@@paulbizard3493 True. It's hard to achieve as much as 70% efficiency, but this doesn't matter. On the flat, the needed power output is low anyways, and on hilly terrain, an electric powertrain will recharge and give back 70% of the energy while with a mechanical drivetrain the energy will go to waste. With an energy bank of a couple of kWh, it should be the better choice for most trips.
Thanks, I was curious about this. One point you have shown but IMO not put enough emphasis on. With this you can easily divide power output between multiple wheels (especially interesting for 3+ wheeled vehicles). You can also easily power a steered wheel (I presume that is what gives the cargo bike around 9.30 that amazing maneuverability). Keep up the good work
Electrom Light Electric Vehicle must have been a part of this video. There is a RUclips channel on how that guy creates and the every improvements he makes.
I was screaming internally the entire time. "Digital"means of or relating to numerical digits or fingers. It has nothing to do with methods of power generation.
& this is objectively analog right? Unless it’s just a computer recording your break intensity & directing an equivalent level of power from the battery, with no direct, variable, connection between pedals & engine.
Right. I thought who came up with calling this "digital". There's nothing digital about it. Whoever thought to call it digital needs to learn its meaning.
@@Padlock_Steve It's genuinely dangerous to use bikes for travel here. I've had two different cyclists die close to places I've lived because they got hit by cars. Bikes in the U.S(at least in the south) are something you take to trails or parks.
Given how inefficient the drivetrain is, you might as well skip the pedals and call it a motorcycle! The pedaling is just to qualify as a pedelec for legal purposes, while the battery and motor does almost all the work.
Remember, that efficiency of 95% for derailleur bikes is fresh out of the workshop. Drive it for a week/month in bad weather and things change. This might not be the right thing for a peak performance bike that gets constant maintenance. But think about a commuter bike, that gets serviced once/twice a year the story is quite different.
@@etherealicer True, but I don't think it ever drops below 90%, even for a really dirty chain and worn teeth. 58% efficiency really is terrible, and that's not even accounting for the extra weight. Still, it probably has a niche somewhere. Public electric bikes schemes seems like a good use case
@@jackroutledge352 It also is not accounting for recuperation. I don't know the numbers (and a quick google search I did has not revealed anything). For me, I can see about 10% loss of speed* (though a good part also comes from poor tire pressure) and I do pretty regular maintenance (oiling / pumping up the tires). I do annual oil change on my rohloff speed hub, as it is combined with more thorough maintenance which usually results in 15-20% better speed. * I daily commute for 2.6km in any weather.
@@jackroutledge352 The day I do my maintenance, my bike is usually in better shape than the average commuter bike (But I'm also pushing it going roughly 30km/h top speed, not bad for an 18kg steel mule). No idea how these losses translate to efficiency, but I think there is a quite significant loss. Of course this is very hypothetical and anecdotal. Really curious about actual every day efficiency of bikes.
@@etherealicer the efficiency of an external chain bicycle drivetrain with a high quality chain with the right lubricant, clean, fresh… is a little over 98%. Dirt, wear, poor lubrication… do lower this but in poor conditions typically stay well above 90% for a bicycles’ chain drivetrain. There is no comparison between a digital drive and chain bicycle drivetrain in efficiency. A 58% efficiency rating is abysmal - think 1-1.5 flat tires for something significantly heavier that costs more. A high torque electric motor is heavy due to copper and copper is expensive. Besides a good mechanical system is typically more durable/longer lasting than a digital electronic version. Hand crank car windows will typically perform without any needed maintenance or parts replacement whereas electric windows will be needing multiple maintenance services and a few parts replaced. The simpler option is typically going to be the more durable and efficient. Digital drive bicycles only come close to being a good choice when talking about e-bikes. Will future innovations possibly change that? Yes. That said in 1890 bicycles featured a diamond shaped frame based around hollow tubing, power went to the rear wheel based on a chain, wheels were made with tensioned wire spokes and featured air filled rubber tires. The best bicycles today typically have the same features. Yes some bikes will have a belt drive. So magical game changing innovations can happen but don’t count on them in our lifetimes. Given the poor execution of many “innovations“ that I see in newer bikes I dread actual changes. Frames are commonly out of alignment, poor welds, poorly aligned bearing raced, sloppy tolerances… are typical issues with new bikes. So if a drive system which looses 21x more energy, requires the bicycle to be significantly heavier while being more expensive and most likely harder to work on is something which sounds like an amazing innovation to you and deserving your money than go for it. Yes 21x more energy 98% vs 58% or 2% vs 42% loss.
could be a vice versa promo vid: "now we can use chain drives!- they have almost double the efficency than our regular digital(actually not digital) drives. They are lighter, cheaper, easier to manufacture and everybody can repair them themselves and you will NEVER have to charge them!.... what a time to be alive!!"
Exactly, as an Engineer .. this idea of absolutely STUPID. But could make some sense for a plug in battery powered bike that would occasionally be pedaled.
@@KrustyKlown ok so this is what i dont get then. Mr engineer, why is it that diesel eletric on trains exist? Ik, i also dont get how it is better than a drivetrain but its like the only way they do it. How come?
Omg it would be incredibly hard to drive such a bike with so much energy loss! Imagine how much more pleasant it would be to switch back to a normal bike and immediately discover your strength can propel you so much faster and easier! I can't see why anyone would accept lower energy efficiency. Battery power assist is what people want.
Exactly. A clean chain is 98% effective. A great electric motor is 90-ish %, plus the generator at your feet, making a total efficiency of what, 80% in near ideal conditions? No one would want to ride a bike with a chain that only got 80% because it would feel like a brick.
I'm working on a far better breakthrough in bicycles: A hand crank, attached to a generator, that charges a battery, that powers an electric burner, that boils water to produce steam, that is channeled into a turbine, that spins a generator, that charges up a battery, that powers a light, that shines on a greenhouse, that grows lettuce, that's fed to rabbits, that run on large hamster wheels, that are mounted on the rear rack, and connected to your rear hub via belt drive. There's a basket on the front of the bike that holds the lettuce that you feed to the rabbits as you cruise along. It's not quite as efficient as a chain drive, but you don't have to worry about grease.
Another benefit: AWD bike with traction control (for commute in slippery snowy conditions). Also front and rear motors may be optimized for different speed/torque.
I think an AWD ebike would be a very very interesting thing to handle obstacles with. You could climb a lot of obstacles with some watts pulling you up by the front wheel!
The conventional systems have been refined over many innovations and iterations for many decades. Bikes today are surprisingly more efficient and better than the bikes we rode as kids. But electric-powered and electric-assisted bikes will always appeal to people who lack strength and endurance.
I think you hit the nail on the head. I have made 2 electric bikes from kits and bought one prefab model. I could see this design excelling for those who just city cruise or easy trail riding which could also easily be done with existing chain drive pedal assist. Nevertheless, it’s an interesting concept.
Great video! I built my first digital drive trike in 1986 and dismissed it because it only showed about 50% efficiency. Things haven't changed too much.
Things often get more expensive and complicated to start with, then when they're at the mass market stage they're cheaper than the alternative - I see this being one of those. If it catches on it will end up being significantly cheaper due to the types of parts and engineering tolerances required vs the current chains and cogs.
@@krane15 But technology is supposted to give us benefits. Like the bulb over the candle. This gives no real advantages. Single speed bike, even not geared specificaly for the rider and conditions is going to be better.
@@M_Jaggard You really think bicycle chain has more precise manufacturing tolerances than generator or electric motor..? Or that one day a simple chain will be more expensive to manufacture than an electric motor or generator..?
love my shiny chain, the chain sound, the shifting sound. Bring a chain break and you will always get home if the rear derailleur gets wrecked...shorten the chain and make a single gear to ride home. I also still drive a 5 spd car ...love it, its perfect. Whats the cost of fixing a digital drive , whats the reliability? Can I fix it myself out on the road ? Exactly...no thanks.
A bicycle with digitally controlled fully electric drivetrain. I think "electric drivetrain bike" would have been a much better name used in this video.
On a normal bicycle you don't have to push through the dead spots of the crank rotation at all. You can also pedal harder with one foot than the other. Pedal resistance on a chain drive bicycle is infinitely variable at any time without needing settings, you only push when you want to, and if you don't push, you can still keep rotating the pedals.
This is still an energy-consuming process because you are not fully relaxed during pedal rotation. Digital bicycles could provide a more efficient way to spend your energy rotating pedals. Personally, I think the efficiency could achieve 90-95% with the right digital control system.
@@Anonymous-sb9rr You could adjust circuit to charge capacitors/battery when inertia push your bycicle forward. If the current flow is adjusted right you won't feel the difference in applying force. Also some energy of bicycle could be applied to decrease pedal resistance for more smooth pedalling. Like the narrator said, technology is more suitable for electric vehicles with batteries.
Great video. I can definitely see this being useful for electric bikes, particularly applications like delivery bikes. The efficiency will need to improve a lot for it to be serious competition to conventional drivetrain.
At this point, just get an electric moped to commute, this digital drive system seems just like a legal technicality to get electric cars and light trucks into bike lanes.
This is a bit of a flawed stance isn't it? Most parts on a normal bike are required for its operation too. If your chain fails, or your gears fail, your normal bike would be pretty useless as well. There is something to be said for not overcomplicating an elegant design, tho. This digital drive system currently seems to have significant wdisadvantages in comparison to the old system, but both have many single points of failure. One could probably argue that the digital drive one has more redundancies than a normal bike, as it could use motor braking when normal brakes fail. Or that it could run without the generator pedals for a while if there is juice in the battery.
@@MrJoerT Sorry I don't subscribe to the idea that adding electronics/electricity to proved design is a step in the right direction. 50 years down the line a regular bike may still be operational, this: without an industry to produce replacement parts, you can kiss it goodbye. I like my gear resilient, not fancy.
The best use of this would be a 2wd otherwise nah. What I could accept is a super capacitor that charges at regen and discharges to the hub motor at maybe 100w maximum as a "KERS" variant instead of a full electric bike. would make sense in a city environment with a lot of stop and go. And the super capacitor would be integrated in the frame as it does not need external charging.
A 2WD bike with this technology would be even worse, it would be less efficient, more heavy, and would take twice the effort to pedal because there is twice the number of motors.
@@theyeetus1428 Yes I know, but other than an extreme case where you actually need 2wd, I dont see a point of this type at all, as a 1wd setup it just doesnt have enough advantage vs standard way. But there is no other solution for 2wd so that is the only viable application.
Great idea, and then when your battery runs out you can use you can pedal like crazy to compensate for the huge losses in the system. Just keep using a chain, it's what you need in a bike.
@@davidmowbray4230 My e-bike has a ratchet mechanism to automatically engage and disengage the motor, so there is basically no additional resistance when pedalling unassisted. Isn't every e-bike like that?
@@StefanReich they're just heavier. Regen brakes would be good for getting some energy back but i'd use a solar panel on the back before pedaling to generate electricity.
@@skirnir-atf they used to make electric bikes with the assisting motor in the front wheel, making them essentially awd bikes. They mostly don't exist anymore, because it's not comfortable nor safe to have too much weight in the front wheel, and because a bicycle with a driven front wheel is dangerous. If the front wheel loses grip you almost always fall down, and if it's slippery out a driven front wheel loses grip easily. Nowadays you pretty much only see rear hub motors and middle motors.
I can see this system being more popular on Velomobiles due to the more complicated chain setups those seem to have. There's a recumbant or two that uses it too, but they're made-to-order things.
Yes! I was thinking this could be great for recumbent ebikes. They otherwise need *really* long chains - with extra cogs to guide them - and belt drives aren't suitable
I ride a trike and I'm not terribly interested in switching to a drive train that is heavier, less efficient, more expensive and can't be fixed DIY in the field. It might be a good option for people who need an electric assist due to limited mobility or elderly folks but that's about it. I tend to do pretty long rides (50+ miles) and I highly value the capability to fix nearly any mechanical problem roadside. Just knowing that I will be stranded if something goes wrong with my drive system is enough to turn me off from switching to a 'digital drive'.
This could be a great solution as a regen/Top-up for an E-Bike, but not as a replacement for a direct drive (like a chain or belt) on a regular bicycle. The one big feature missing from E-Bikes is regen braking. This at least would give you the option to add a few watt/Hours to the battery on easy sections of a ride.
There is a fair amount of slow speed balance and control that is "felt" through a physical connection between the drive wheel and the crank also. I would like to try riding one of these to feel the difference
@@MidwestFarmToys Low speed balance. Above about 2 kph I couldn't care less about a non direct link between my feet and the rear wheel, but below this speed you actually rely on forward thrust to keep balance. If you had a unicycle powered like this, it would be unrideable. There is a mechanical relationship with this and bicycles
@@MidwestFarmToys It not a problem at all. Unless your consider advancements in technology a problem. It is the nature of all thing to evolve or advance unless you're a Luddite and want to remain in the dark ages. This is just another possible step forward in bicycle evolution.
@@MidwestFarmToys yes I agree, converting mechanical energy into electrical and back to mechanical again, is overly complicating a simple design and to me seems..... excessive. Mid you I'll argue that an automatic transmission is bordering on extravagance too.
I can see the advantages, much like electrical cars, it has the best potential in a city with lots of stop and go for regenerative braking, and a relatively low top speed. The concept is interesting, and I'd love to see where it goes. To an extent, I can see hooking your bike to an external battery.
Interesting concept, however calling it "digital drive" is quite the misnomer - the signal doesn't need to be digital (0/1) here, it can be analog as well. The grand difference is that the power is transferred by electricity, not mechanical movement, therefore the name should reflect that.
@@xe-wf5iv I disagree - driving a motor via PWM would qualify as running it digitally in my mind, and technically you could PWM the generator side as well. Not a big fan of the naming, since I doubt it will always be PWM though, hence my original comment.
@@Ox4C4A No, PWM is analog, because PWM does not represent a numerical (digital) value. The fact that the signal has 2 signal levels, does not mean it is digital. Furthermore, the duty cycle of a PWM signal has an infinite number of steps between 0 and 100% if you generate it witih a common PWM driver, like an NE555 for instance. You can, however, convert a digital signal (such as the output from a digital RPM counter of the pedals) into an analog PWM signal to proportionally send drive energy to the wheel motor. In that case, there will only be as many duty cycle values as the number of binary bits you reserve to represent the power level. All the processing to control and generate the PWM signal, are digital in any modern vehicle. There is an exception: somewhere in the 1980s, some smart guys developed a way to encode bytes of data in such a way that they would form a correct PWM signal, but also actually represent bytes of data that you can feed straight into computer memory or disk storage. They used this to digitally record analog music cassettes. The natural lowpass characteristic of the tape recording heads ensured that what got onto the tape wasn't the raw PWM signal, but a smoothed out normal analog signal. At least that's what i remember from that article. It's very interesting, worth trying to look up if you enjoy early computer tech.
When I was commuting daily by bike as a student, my yearly maintenance costs were less than 150 euros (most of that was a yearly service by a mechanic). That is insanely cheap for something that I used every day, rain or snow. There is a great strength in the simplicity of the chain drivetrain: it makes it easy to learn how to service it, and straightforward to produce spare parts, you can even learn to do it yourself. Compare that to the nightmare of modern car maintenance, where even software errors can (at least temporarily) brick your car.
If you combine it with an ebike with proper motor controls (including torque sensor), I cannot help but wonder how good a front or all wheel wheel drive would be. We saw in rallying that all wheel drive was absolutely the way to go for control in difficult circumstances, so it could make sense for bicycles too. I just don't like the ones that do it currently, because the motors are never properly controlled and just go full torque the moment they're activated.
I actually think a torque sensor is the wrong way to go. Why? Because in many situations you want to be able to modulate your speed. If the only way to slow down is to work less, you cannot build up power for that next hill. And if you don't save up, you will fail to make it up that hill. A hand throttle and optimizing your cadence and output you're willing to put in, could allow you ride with almost as much efficiency and certainty as you currently get with a parallel (traditional) pedalec. I think this video started out with the right concerns, that weight and efficiency losses mean we'll continue to use chains and belts.
@@karlInSanDiego You are absolutely correct. I immediately fell back to my "I hate these on normal bikes" mindset when I started thinking about front wheel drive. I do think they could be quite interesting and possibly advantageous though.
All wheel drive bicycles already exist - and have for decades. Look up christini all wheel drive bicycles. They have more control descending and improved drive traction for climbing. They work. So far the design hasn’t taken off. It doesn’t look like they will anytime soon.
Yupp, but kiss it. Pedals drive generator and charge battery. Battery drives motor. 1 gear , like a Tesla. Gears and chain on an ebike are just plain weird. Huge thanks .
All wheel drive is not needed unless you ride up and down soft sandy beaches. A military combat situation where you need to sprint with a burst of speed would be helpful. I would like to build a all-wheel drive bike just for off road fun…
I think having a motor to help you speed up from a stop, or while riding uphill, as well as regenerative breaking are a good idea. But I'd make it a hybrid, so that there are both the chain system as well as the motor and a generator, so you get the efficiency of a chain drive, but some advantages of the digital drive.
@@digitalspecter It says you need a different type of motor called direct drive motor for regen brake, which is heavier than normal motors. It also adds resistance on pedals, and creates heat when it brakes. All that for around 5% of battery saving.
@@aaaaaaaard9586 a lot of ebikes have direct drive motors, they're cheaper than mid drive. They're a bit heavier but way more reliable and don't require replacing your chain as often. A big benefit of them is when you're using the regen braking is slows you down without wearing out your break pads.
Weight distribution favours rear wheel drive. Body position while peddling will always put more or most of your weight on the rear wheel, so it really does make the most sense to keep the drive power in the back. Similar but opposite to why the front brake is more effective than the rear. The second disadvantage in a hypothetical front wheel drive bike is if you lay down too much power, you'd lose steering control and could easily lead to the front wheel washing out. Back to the brake comparison, front brake control is a mountain bikers most important skill. Managing that the front brake is capable of the majority of your stopping power when riding downhill, with the risk of locking up the front wheel is an art. Could there be a use case for 2x2 bikes, where both wheels have power? Possibly, but they'd be few and far between. If riding in low traction environments like snow or gravel, there could be someone out there that would benefit from a front wheel that could deliver power. More so with utility bikes or heavier enclosed bikes like in the video. My 2 cents.
Recumbent bikes with FWD do exist but you are creating more problems than solving them. In those cases you either have to sacrifice turning by having a regular steering on front as well or having a reduced turning radius with rear wheel steering.
I think the hybrid concept is great; you can control the bike speed independently of your pedaling speed. I could see an athlete commuting to work, really putting in a tough workout, yet his bike is moving at a moderate pace along a busy bike path. And, of course, you could have it where you're pedaling at a moderate, constant pace, while modulating your bike speed according to traffic conditions. I've been a fan of the generator/motor/chainless concept for some time now, and this video does a great job of discussing the pluses and minuses of current technology.
Only problem you need to use the energy at somepoint if you generate all the time. Like you need to recharge an e-bike you drain all the time. You also could partially short circuit the motor and dicipate the effort in heat. But that's kind of a waste. Also if everybody drives a view watt extra a day for 30min this adds up to an significant amount of power over a year.
You mean, like gears on a normal chaindriven bike? You've literally described exactly what gears do. You can't have the energy input constantly greater than the energy output (ignoring drivetrain efficiency).. Even if you had super capacitors or a battery to store additional energy, these would eventually reach a state of maximum charge and you'd be back at square one. The use case you've described is already achievable with gearing and the addition of a dynamo light or dragging the brakes.
@@MrHaggyy i dont think you can short circuit the motor very long. the energy will go towards heating up the wires. you can short the motor on a resistor though.
@@MrHaggyy i dont's think spending energy is a problem at all. when your battery is full it will just stop charging, and your generator will do nothing. and i seriously doubt there will be a case of "too much energy" ever.
the biggest problem with independent of your feet controls for speed is, weel, it's independence. you'll need a gas crank on your handlebars and to relearn hardwired "pushing pedals make you go brr". which could take a lot of fun out of the cycling experience.
I thought this when I saw the emergency closing cranks for water tight doors on ships. I used to work in ship building. You simply rotate a crank and two very large cables transfer the electricity generated to the door motor that closes or opens the door depending on the direction. It essentially is the same thing.
@@K1989L Actually quite digital for the controller driving the motor. For efficiency a synchronous motor is needed which means digital controller has to generate a variable frequency waveform. The controller has to be aware of current speed and current power requirement.
@@K1989L Synchronous motor where the digital controller does all the work. Full time electric cars have no gears. It is all magically done by the digital controller.
I truly appreciate this thorough review of the digital drivetrain for bicycles. What I like most is the fact that when pedaling I would be able to keep the cadence the same regardless of terrain. Also regenerative breaking and recouperation of energy when going downhill is awesome.
Yeah, no... People like you don't seems to understand that electric motors and generators are far from having a perfect efficiency, you'll basically need to force about 2x more to get the same speed as normal bicycle so I'm not sure that's a very good tradeoff just to get a tiny bit of regenerative braking once in a while...
@@Alfred-NeumanElectric motors nowadays, at least ones suitable for this, are over 95% efficient. This goes for both the driving motor and the generator. The motor controller can and usually is over 93% efficient, up to 97% efficient. This is literally more efficient than belt drive. Make it recumbent and enclosed, and it would be way better (faster) than a usual bike, more efficient at speed, and with a small battery, better overall for commutes.
@@vladlu6362 But is it worth sacrificing repairability ? Especially when there is a lot less data on the reliability of this technology. On my cheap bike if something breaks I can fix it myself in less than an hour for pretty cheap. If the motor or generator breaks, it's gonna be an expensive repair if it's even possible.
Great video! The use case I have always thought this would be best for is an e-bike recumbent because regular recumbents have to have super-long chains to get all the way from the crank back to the back wheel which are kind of annoying. "Digital" bikes will have lots of fancy electronics but really you just need two dials: how much crank resistance you want and how fast you want to go; and something to tell you the range you have left given what you have set those two dials to.
Agree, for a recumbent it really would be a big advantage. The aero advantages would compensate for the inefficiency, the power transfer wouldn't be nearly as tricky as a mechanical recumbent (thus the relative weight penalty is less than in the upright case), you could easily add rear suspension which is a big boon for recumbent, and the electric drive makes the startup less daunting.
This is the first such a comprehensive video on digital drives, congrats. Think there is a great future in it, with further tech advancements. One special drive I have recently seen is "Revonte" - a hybrid, stepless automated drive and gearshift - it works like Toyota Prius - and imho it will be a killer drive until digital drives fully mature, with same "software defined platform" benefits as with the digital drive. Can't wait until those bikes hit the production!
There twitter is abandandonded in 2019 and there recent blogging is not persuasive.... very delayed even channel here is 2021 arguing "artnered with EAV, Lavelle bikes, and Tunturi bikes. "
This will not have "a great future", chains have an efficiency of about 97%. That is insanely high, quite literally nothing compares to it. So it would be really dumb to throw that simple efficiency away
Love the channel. Currently among the most professionally produced content anywhere with well researched detail, stunning visuals and great explanation across the world of cycling. May you continue to enjoy every success.
Jesus chill out, it's decent but this is a pretty amateur voice over ontop of stock footage, no need to make it sound like the Interstellar of cycling content
Comprehensively researched and well explained, as always. And I agree with your conclusion: it's not an alternative drive train for unassisted bikes but it will likely displace the mechanical transmission bits on e-bikes.
If you had said 'some bikes', you could be correct. Bikes in general? Not a chance. This is a solution looking for a problem. Bicycles when invented and bicycles in 2022, still the most efficient mode of human powered transportation. Why throw that efficiency out the window? This will be super duper niche, and ultimately will be a complete failure.
@@joeshmoe7967 the way most people ride it it is quite inefficient, most average people pedal 200W and have the middrives in turbo, and Bosch CX peak at around 700-750W infact, not the "250W" European limit that means you got 200W pedal power and 700W assistance so 900W total, if you went to this mode it would be like 820W (200W effort but 40% loss, 120W) and the 700W your consumption wouldn't increase as the power is limited, still a marginal difference in the end. not only that's great but you'll have the ability to fine-tune the feeling of the pedals, your preferred cadence etc in software as you can vary how much power the pedals generate basically, and you've got none of the issues a normal drivetrain would/could have (derailleur adjustment, chain cleaning, chain skipping, or just no changing gears in general) it's like having a cvt without a cvt.
@@theyeetus1428 in cars, yes, on ebikes it's just too expensive in cars the problem is that people want to hear shifting noises, which is retarded in my opinion, why would you pick something less efficient? but whatever since i've got a bbshd on my ebike i haven't ever shifted as it has a great rpm and power range, it can climb hills and reach 40km/h in gear 3/7 (it's limited to 25km/h cuz of Europe trash rules but it can), but since it's power limited (battery current limit) rather than increasing in power as it goes faster (motor current limit) it's perfect, sort of, more torque and power wouldn't hurt but it's fine at 1500W electric cars (no shifting) and no-shift ebikes (enough power or cvt) are the best either way. I mean nobody should want to really slow down cuz of a normal uphill, it makes the ride even more boring
Stunning! A bicycle chain has an efficiency of about 90%. The power efficiency of an electric motor as well as the generator Is about 70%. So you have to push twice as hard to get the same power on the wheel. Admittedly you could add battery storage and use the energy of regenerative breaking to the battery. However an efficient generator, motor and Batteries will weigh in at a substantially higher weight than the traditional drive train. So bicycle frames are made out of light weight materials and then we load them up with heavy clutter. I guess someone might say it is a great idea, but apart from playing with new tech, it doesn't make sense on a pushbike. The economics will probably look better if you add the generator to an electric bike.
70% is not half of 90%, this statement alone should be reason enough to not take you seriously. The rest is also just guesses, not even educated ones. I’m so tired of people playing experts on things they have watched a single RUclips video on.
@@foximacentauri7891 so nice to be fast checked. If have taken my numbers out of my old electronics reference book. Please share YOUR sources and explain how a bicycle chain manages 30% energy loss. Then we can see who can be taken seriously.
That is what people said when others put chains and pedals on their walking bikes😉 In all seriousness. No drive-train lasts that long without maintenance and parts-replacement (unless you don't use it).
@@jedibusiness789 The kind of maintenance that is not required in a system like this (well, you still have to maintain your tire pressure). I'm talking about replacing the chain/cassette/derailleur(s)/chain-ring(s)/gear-cables and then adjusting it, so the gears change properly again. There are really only 2 components that will break on an e-bike (from the e-drive, commonly it is actually the chain/derailleur part that breaks). Motor controller and of course your cables/connections. Both are easy to fix, they take very little skill and won't cost much (certainly not more than replacing your chain/derailleur). There is pretty much no need for specialized tools (maybe some torx-bits depending on your model, but that is not more special than a chain-breaker). Longevity and ability to repair is really not a concern. Efficiency is (though it would be really interesting to see a comparison to a bike that has been used for a while and including recuperation).
@@etherealicer If efficiency is important, this dual motor is far away from the solution with over 40% power loss. A normal chain drive bike that has been beat to hell would never lose more than a few percent of efficiency.
I could totally see this style of drive train replacing chain drives on E-bikes. You could even ad a sturdy kickstand and convert it to an exercise bike to charge the battery.
Regen braking on a bike is useful for a mountain decent, but for rolling hills you don't want to curtail downward momentum by using regen braking. It's why almost no one in the e-bike world bothers. You rarely want that effect, and it's also got an efficiency loss. I appreciate this primer. Too often people assume it's an obvious evolution of bikes. but that weight and efficiency penalty are not worth it in most instances. The Podbike, Arcimoto Mean Lean Machine, and some other velomobile type startups are using indirect series electric drive too. These rely on big batteries to make up for the fact that you're losing so much efficiency to the double conversion at the same time that you've encumbered yourself with much more vehicle weight.
will be probable the regen work with an special brake lever or adapter that will works with brakes with some adjusting. so instead fadding brakes on reductions the regen act and when you need power the brakes act. this will be increase the pads durability and range to modulate. but the cost and weight is the problem
WTH are you talking about? Regen braking is activated just like braking. Regen braking has nothing to do with chainless drivetrain. You just need a hub motor without freewheel. I have regen on my e-bike. There is a contact on my brake lever, and then I choose the braking intensity with the accelerator. In a city environement (Paris), when I use regen as much as possible, I get 15% of my energy back. 10% when I'm not really into it. In mountainous environement, you get around 30% back. What's great about regen, is that you wear your brake way less (like with EV's), that mean way less maintnance on the bike, that the biggest argument for regen. About the chainless drivetrain, I'm on par with you. Having 2 engines instead of one + a belt system for example, is way more fragile and complex. If your electronic fails, you can't move anymore, with a physical drive train, your bike is still a bike.
If your bike is not an ebike, then this whole concept is total nonsense. Nothing can compete with a chain drive. But if you have an e-bike anyway, then maybe it could make sense. But having, essentially, two motors will be a disadvantage.
I think I'd always rather have a pedal assist e-bike with a regular chain. The chainless electric bike seems like a novelty that exchanges efficiency for some cool factor. Which granted some of them do look cool and futuristic. An ebike with regenerative braking to me seems like the best path forward for bikes. Or just ride something cheap and human powered that won't get stolen, that's probably the most cost effective. Ebikes are already being banned on lots of trails in the US unfortunately, and likely digital fall under that same ban.
ebikes are banned because the battery can allow the bikes to move faster than a normal riders speed. US law regulate then to under 25 mph unassisted but people alter them , thus the ban.
For a regular bike, a mechanical electrically assisted drivetrains makes more sense. But for e-cargo-bikes, this type of drivetrain can be much better than anything chain based.
@@danc2014: I don't know where you're living, but Michigan allows E-bikes on its trails, for the most part. The way the statutes are written is that an E-bike is restricted in top speed, but for some reason, a human-powered bike isn't? I can get a 26" 21-speed MTB up to 45 mph on flat land, with slight variations on pavement. Which, by the way, is the actual speed limit on some roads around my area. Point is, I see no point to restricting E-bikes according to motor rating or top speed, when anything below a 11.1 kw power output rating is not allowed on interstate highways and freeways only (i.e., limited-acess highways). And Interestingly enough, the only type of vehicle whatsoever that's rated at some kind of class are commercial vehicles, based on GVW; number of passengers that can be carried; and number of axles. Not even cars & trucks are regulated by motor size or horsepower, which discriminates against E-bikes, given that speed limits exist for a reason, and most E-bikes have speedometers. So my question is, why not just simply say, "E-bikes are e-bikes, no matter what the power output is, and the only obligation an e-bike rider has is to adhere to the speed limit of whatever road they're on, and that they are prohibited from all limited-access highways"? The rules for E-bikes just seem arbitrary and discriminatory, is all I am saying.
As a tech head this is friggen amazing... As someone who loves the simplicity and the ability to maintain a bike at low cost and low knowledge(as in a car takes way more time to effectively maintain a car than to learn how to completely work on a bike) is in-valuable.. This "evolution" just means normal people can no longer work on their bikes. Imagine you have a 1hr by bike commute and your bike breaks down, whatchu gonna go, call roadside geek squad for a bicycle??
Really interesting stuff. I have to say I don’t like the idea of it not having that quick engagement you get with a physical connection to the back wheel. People who are very casual won’t notice, but it would undoubtedly bother long time riders a lot if it doesn’t feel like what they’re used to. I’ve seen it already where riders do a few revolutions before a 4-wheel bike van starts to move.
I think the way with this would be like Tesla did with cars. Instead of trying to make it “feel” like a traditional bicycle they should fully lean into the advantages of digital drive and embrace the differences.
@@christill I hope some takes this up I think there’s a lot of potential here. I already got plenty ideas. For example if you had a digital drive bike with an electronic, daul-sided, kickstand; you could create a bike with launch control! The kickstand goes down and you pedal in place building up surge capacitors. Then with something like a thumb throttle you could launch it. The kickstand would retract instantly as the motors spin on full power! This would be hella fun and kinda funny to go from pedaling in place to taking off like a rocket. But it’d also be practical for commuters. You come to a light and can keep you pace a cadence going then take off back to your pre-set commute speed right away.
well the problem with the 4 wheel bike van you mention is cadence sensing, if it is torque sensing it is instantaneous dependant on controller settings ofcourse
I just came back from Japan after staying away from traveling for about 4 years. Previously in Japan, rather heavy bikes used to carry children were commonplace. This year, 2022, only 4 years later, more than 90% of these bike have become electric. This phenomenon was observed in the Yokohama area most likely due to hills and to the on-time culture. I do not doubt that given a few more years that this new type of digital drive will appear in Japan.
I don't think so, this feels very much reminiscent of the CVT era in cars, in theory it's better but in reality it just doesn't get adopted as much for various reasons (response time, feeling, etc)
Keep the chain but add the digital drive to the front wheel, and synchronize it to the pedaling, that would be an awesome bicycle (at least for me ) able to climb difficult obstacles.
I will say that it'd need a back motor aswell, it just isn't smart to have a lot of power on just the front wheel as it can slip out easily, then 2WD would be better
Front wheel driven electric bicycles already exist, but they are less popular because acceleration feels less natural as you're pulled forward and they make steering more difficult. It's cheaper though than motors at the crankset.
@@Frrk hmm i would disagree with that, a Chinese 500W peak torque sensing middrive will be around €300 a torque sensing bottom bracket for a front or rear wheel motor controller often runs for €80, that is without the controller, motor, wheel etc. when you're talking about cadence sensing, sure, but even then it's still hard to beat the €300 middrive
@@Frrk truthfully most middrives are made by European brands, which also like a large part of the money as profit if ya know what i mean, which is understandable as it's actually very expensive to pay European employee's, atleast in Belgium, The Netherlands, Germany and France, eastern min wages are much lower for example for the min wage of a few years back in Belgium (€1650 a month) the companies had to pay out €2200 or more to the recipients as the rest goes to the taxes
A bike that comes with an integrated upright stand could also have a mode built in where you could charge the battery while peddling in place. Say if you had a commute that was kind of awful you could still pedal it in a session or two during the day, storing your mechanical energy for the next time you ride but not having to get all of your pedaling in at once. This could similarly have the perk of being able to act as a mobile charging station for smaller electronics using this same idea.
I've designed a similar idea for a pedal generator and battery-powered electric motor-driven Kayak. My system does use digital control for the BLDC motor as they are more efficient than brushed DC motors. The overall idea is simply to extend the battery life.
Maybe there are more advantages: less need for rare earths and less weight (which also results in greater battery life). The downside, is you need to convert the DC battery to an AC current and a more electronically complex control system of the motor torque and velocity.
@@Sergio_Loureiro My design just uses a sensorless BLDC motor for prop and one for generator. I'm not concerned about rare earth magnets. This is just a hobby project for my own use. 3 ph AC is automatically created in the generator but then is rectified to DC for battery charging and the prop motor driver. A pretty simple design. :) Prop motor speed is simple in software. No need for constant torque control in such a system.
you either have speed or you have torque you have to choose one if you dont have multiple gearing to use that or your bike quickly becomes a motorcycle legally
@@MrHaggyy no, the maximum power transferred is when the load resistance matches the internal resistance, so this would mean max power transfer at a lower load, lower efficiemcy for same load
"super capacitors as they are lighter" If one compares the amount of power per gram of the two storage solutions (batteries vs super caps), super caps weigh much much more than a battery with comparable energy capacity. Super capacitors have miniscule power storage compared with batteries. Tom Stanton made a video showing a super cap powered ebike *(Super Capacitor Bike).* It was pretty terrible. I watched a bit of the video just now (while finding the title) and I see Tom had also built the motor. It's possible with better components a super cap bike would perform better than the one shown by Tom but I doubt it would work well. If you're going to the trouble of adding a motor and generator to a bike, you'd probably want to use real batteries to maximize the benefits of using an electric drive.
The hall effect, in combination with a supercapacitor, can bring up the efficiency of an electric drivetrain to about 80%. It's not as good as a chain, but most people care about getting to the place that they're going instead of having peak efficiency.
Ever since I purchased a drive shaft bike years ago I have not been a big fan of chains. The simplicity and reliability of drive shaft renders chain drive obsolete in my view. The concept described in this video is very interesting. I have thought about a similar drive years ago but was under the impression the losses of efficiency would be so great as to make the idea impractical. I see in this video that many of those obstacles are being overcome and that is very exciting. Thank you so much for posting this video.
With a throttle you can pedal at any speed you want and have a smooth ride so I don't think it is a bad trade-off. They spend too much time mimicking conventional bicycles when they could have a easier time building the RollsRoyce of bikes.
Great video, but I disagree with the statement that digital drive e-bikes will be better in poor weather - at least in winter conditions like the photo shown as you said that. Battery output drops massively in cold weather, so you could conceivably bike somewhere, park your bike outside, and return to a dead battery a few hours later. Then you'd have to pedal your heavy, battery-equipped bike purely via the inefficient digital drive to get home. I've been driving an electric car for the last seven years, and a cold-soaked battery on a return trip is something I'm very familiar with.
Thanks for adding the complete pros/cons that so many ignore. Electric transmission (non e-bike), is less efficient and needs a battery and e-bike powered transmission (power delivery) system to really show any promise. But, that is certainly a really cool option. I designed a hybrid bike for an international bike design competition in 2006, so the ideas have been around before the tech was there. I can see a company like Canyon really pushing the future on this front. One important note to add: Adding electronics and batteries inherently make the bikes far less sustainable due to the increased materials/batteries/maintenance. And yes, these are specifically electric, but can incorporate digital control.
“E-bikes” aka electric bikes already exist. That’s a motor and battery + chain and pedals. These bikes are technically also electric driven but the name is taken so… lol. Plus “digital drive” is a good name for it given the chains and gears that normally drive a bike are gone and “digitized” in a sense.
First of all, this drive system has nothing to do with "digital." It is electric. Second of all, putting a battery on these bikes does not solve the efficiency issue. In fact, it will make it worst as mechanical power from the peddle must first be converted into electrical power and then to chemical power (batteries) and then back to electrical power and then back to mechanical. Adding more and more batteries will only contribute to further increase in weight. In the extreme cases, it is like someone installing a foot peddle generator to charge the batteries on an electric car. (Probably a dumb idea if you think about how much peddling (energy) to get yourself anywhere.) If the design mostly relies on the energy that is stored in the batteries, then it is essentially a batteries powered bike.
"derailleur gears and chains have improved incrementally over a century and have well and truly proven themselves to be lightweight, high-performance, efficient, and cheap to produce." You said it so well it was almost a poetic endorsement of bicycle chain drive systems that I personally find to be a sweet spot overall ..
When i was a young man I was very fit and one of the reasons was that I cycled 30 km each way to and from work. Having technology do the work for me would make things easier but I would lose most of the benefit of exercise. I also used to swim 2km and run 10 km per day.....I guess the future will invent something to make this easier as well. Still, I would love to give this a go, now that I am old and not so mobile.....maybe this could re-invent my passion for exercise that I once had?
@@Ulbre my point is just that as technology advances, it becomes normalized. you don't even think about shoes as "using technology to make walking easier" but it that's absolutely what they are.
I don't think you got the point. You will still have to pedal this bike. A bike like this with just the generator and motor would not have any more power than what you provide.
and regen will be an easy option...love the idea. Combine it with a decent battery to overcome the disadvantages in system losses and you have the ultimate bike imo. I've often thought about this concept and wondered how long it would be before it was put the market.
I've had an idea for years about putting a system like this in an enclosed recumbent design. you could even out the pedaling intensity so you're not all sweaty commuting to work, plug charge, solar, or use it as a stationary bike to work off lunch and charge system, then pedal as much as you want with a surplus of energy. system like this with a decent battery would afford creature comforts like heat and audio due to reduced range anxiety, allowing people to cycle when they wouldn't due to weather and hilly terrain
Any idea how slow a solar panel charges? A night rider could let the bike charge “over day” I guess. Also need more coal energy to make a solar panel than what coal directly delivers. I am looking for a coal fired bicycle. It is the most “green” of all.
I think a bundle of super-capacitors could be a really cool alternative to a battery as well. Charge them just off the regenerative breaking and have a button on the handle to discharge them one at a time as a "boost" where the bike runs under its own power for a few seconds. Capacitors have a much longer lifetime than a battery and don't suffer the power loss over time or in cold weather. Having several boost charges to help you get up hills or get back up to speed from a stop would be very useful. And so long as you were using your boosts as frequently as you charged them you'd technically be getting that efficiency return from regenerative breaking just the same as a battery. Ofc It would also be very video-gamey in a fun way.
I don't think bicycles typically spend enough time braking to generate enough electricity to do much meaningful work. Especially not one as slow as these would be, given the poor efficiency.
@@tonyb9735 this. the amount of energy that can be recouped via regenerative braking (obviously) correlates to the amount of energy that you waste on braking. with a car this can be significant because in the city traffic, you are bringing 1-2 tonnes of weight to a complete stop from like 30-50km/h all the time. But cycles weigh significantly less and most cyclists ride with a bit of foresight to minimize the braking that is required. on long downhill roads you may be able to collect some energy, but then again on most downhill passages i pedal a bit to get faster instead of constantly braking.
I especially liked the contraption with the solar panels on it; they would also give some protection from rain and snowstorms. I can only imagine how much fun it would be to ride this thing 15 miles to work during a winter storm in Boston, MA where I live. Thank you for opening my mind to possibilities I never knew existed.
Recumbent bike design with a chain/belts has always been a challenge. There will be some neat designs out of this. Though the never spoken about flat tires will still stop wide use.
Great Video! It's interesting your analysis on digital drive bikes is similar to what I found on Electric vs Hybrid vs Gas cars. The gas cars can reign supreme at very specific speeds based on their transmission and on flat terrain with no stops. Hybrids and Electrics both handle the stops as well as down hill sections wonderfully with regenerative breaking. Hybrids are great as some can offer redundancy not often talked about or utilized well helping with major issues since they can essentially have 2 drive trains. Whereas Electrics only have one to deal with and so can reduce complexity. Though not weight since batteries weigh more than gas.
Well done video and I agree with your thoughts about not really practical for regular bikes but very likely a great fit for E-bikes. I’m about 9000 miles into riding a BikeE recumbent with the Grin rear wheel 212 ready to roll kit. Wonderful set up but the chain length and maintenance are my biggest challenge, not to mention that I need a 70 tooth front sprocket to peddle the speeds above 20 mph. I want a generator crank!
Regenerative braking is a nice feature, but nearly all bicycles have a freewheeling rear hub, and that has a lot of advantages, too. Remember that air resistance is a powerful "brake" on a cyclist going downhill at typical speeds. With sufficient regenerative braking, one would have to pedal more, or use the motor. That's one reason few e-bikes have regenerative braking.
I don't think that you'd need to have the regenerative braking active whenever the rider stopped pedalling. It could be controlled, by the rider, with a digital brake lever
@@pedalinpete - Yes, but the less Regen is used, the less value it provides relative to the cost of installing it. At any event, Regen braking should be activated with the brake levers, so the bike can still freewheel. The freewheel hub is one of the most energy efficient parts of a bike, and due to physics, no other vehicle besides a bike and a train roll as far without power.
@@pacificostudios Regen is worth it even if it used battery. Magnetic braking is maintenance free, intrinsically anti locking and works the same in all weather conditions. Also the brake lever feel does not change over time. Bicycle brakes are super annoying to work on and are very high maintenance.
@@difflocktwo - Don't forget that Regen braking cannot actually stop a vehicle because braking force falls to near zero at low speed. Some form of friction brake is needed to actually stop a bike safely, even if that's your foot.
@@pacificostudios You can use a bit of battery to stop. Think about "reverse". Basically you can use battery to drive the motor in reverse to keep braking force high even when it doesn't regenerate. Many shared scooters use battery to lock the wheels if you try to move them.
What if: we left the rear wheel driven directly by the pedals (eliminating conversion from mechanic to electric and back to mechanic), and installed the motor hub on the front wheel instead? This is the setup for the parallel hybrid (in contrast to the Serial hybrid in the video). I think the motor can be used for regenerative braking and biking uphill. For the regenerative braking part, supercapacitors are more adequate than batteries, because they can charge quickly. Batteries can be added to extend the range of the motor when you don't pedal. In addition, you can start charging the batteries when the downhill ride is long and regen charging exceeds the supercapacitor's capacity. My aim is to keep the motor disengaged when you don't use it. It engages on regenerative braking or when you decide to use it. My experience with the standard e-bikes is that pedaling without the batteries is difficult even at walking speed. Just to start moving on a flat terrain necessitates standing on the pedal! I can pedal uphill quite well with pedal-powered bikes, but I find e-bikes much harder to ride even on a flat terrain without batteries. Clearly there are some efficiency losses here!
Good idea. This is how the Tesla Semi works. Rear motor optimised for 60mph, front two motors are mechanically disengaged except for acceleration and regen braking (and maybe counter jack knifing).
Efficiency of chain and sprocket is over 99%. Efficiency of inverter is around 95%, and efficiency of electric motors is 91% in best case conditions with average is closer to 70%, both times two for generator and motor separately, for the total loss of useful leg power of 27% at best and 55% average - just for the sake of a gimmick. There's a very good reason chain drive hasn't been replaced with anything else for so long. The closest competitor is timing belt, and it's ~1% less efficient by itself and you're stuck with hub gearbox which incurs another ~5% efficiency penalty (or no gearbox at all).
The moment there is a battery and an electric motor on a bike, there is no technical reason for it not to be capable of "driving on its own". It is only a legal thing that the motor stops operating when you stop pedaling. This is true for all e-bikes. So while a motor only driving the bike without added mechanical input from the user (using electrical input instead) may be seem different, it actually really isnt. And because the motor does a large part of the work in the first place on e-cargo-bikes, it also is shockingly unimportant how much input energy the human actually provides.
I have a better idea: why not put the VR goggles on and rotate a stationary mounted set of pedals. Behold: the ultimate digital bike, the bike of the future!
I really like this idea for city cycling. In some of the major cities it often feels like you are waiting for traffic lights half the time. You just need a three-wheeler bicycle to make it work. Also riding downhill, you could recharge your battery, where now you often just stop pedaling. Outside the cities some people use recumbent bicycles. Those have very long chains, so the difference in efficiency might be a bit smaller. I am currently in the Philippines, where in some cities you see a lot of electric tricycles which they call ebikes. Most of them don't even have pedals. As I am used to cycling, and like the workout, I would be more likely to buy one with pedals. Range anxiety is a thing for me, especially since batteries here lose range very quickly.
Some more points I like to note. 1. There is an e-bike named Electrom which is a recumbent design with an electric drive. This bike features a clutch at the pedals and the electric drive, allowing it to switch between a normal electric drive with the electric motor driving the chain and a series electric drive, where you pedal to recharge the battery. Such a clutch allows you to both do regenerative braking, charging using your pedals and using the more efficient traditional bicycle design with chain. Of course, such a design is going to be expensive and heavy. 2. Note that the chain drive electric bicycle design is not the most efficient design. If you want to go for a design that can provide more power, one of the things you can do is move the electromotor to the wheel, to increase efficiency. 3. For a city bike design with regenerative braking, you might want to switch to a design with a capacitor. The downside to a capacitor is the much lower energy density, meaning that you can only use it for accelerating after braking (or maybe something like a 1 km range), but the efficiency is higher, so you would not need to charge your e-bike. Braking provides a lot of power during a short amount of time, something a battery might not be able to handle as well.
This is a very interesting idea... I think I agree with the take that these will start to become more common in e.g. larger more stable cargo bikes as battery charging could be done at optimal leg speeds even when stopped. For things with two wheels though I don't see this being all that appealing, since you are relying more on regen and downhill movement to recharge the battery. For example I know I would always rather have something direct drive when starting from a stop for stability reasons, since this is one of the main reasons I prefer commuting on a bike and not e.g. my moped. The weight and CG will also matter quite a bit in that scenario... but many of the bikes shown here had top mounted batteries. Seems like the current products out there are a little miss-aimed for the market of traditional cyclists... maybe we see this becoming more popular with new riders but I think this will be a hard sell for traditional drivetrain owners (even on ebikes).
Very interesting. With regards motor control, there’s a company called EXRO that has patented and in production modules to take care of this. I think if they brought it down to 48V it would solve a lot of these issues.
Very nice overview, however I do feel you loose a lot of control over your bike. As a cyclist, the ability to determine how much power you provide on your pedals is pretty important. Thinking about steeps hills and such. I would image it feels pretty weird to have a difference in peddling speed and the bicycle speed. Would love to try it out though!
Maybe we need a dual mode drive - when you pedal forward, you drive a fixed gear belt (at your typical cruising speed). When you pedal backward, you power a digital drive. The belt drives the rear wheel, while the digital drive generator/motor drives the front wheel. This dual mode system is still very simple, but you don't sacrifice efficiency at your typical cruising speed.
A decent thing for the next gen of cargo/delivery bikes doing last mile stuff. For propelling a solitary human and their backpack over any distance that's a massively inefficient lump of complex solution to solve a challenge already comprehensively solved a century ago, and recently tweaked with e-assist. The argument about chain and derailleur is no longer valid with belt drive and modern hub gearing. It misses the point of why the bicycle (and e-assist) is so efficient - they take the force of our strongest muscles (quads and glutes), and using leverage and gearing transmit and multiply that energy into forward motion. This doesn't do any of that.
Regenerative braking on an ebike isn’t all that it’s cracked up to be. I’ve wrenched and sold bikes with that feature - I wasn’t impressed. With a car weight to drag ratio is much more favorable compared to a bicycle so you don’t get much extra benefit. With ebikes that offer regen braking or while coasting - if you run out of battery it’s worse than pedaling a bike with a flat tire and heavy whereas a regular ebike is just heavy. Regenerative braking systems favor hub motors vs mid drive as well. As someone with 20+ years of bike industry experience - I wouldn’t buy an ebike with regenerative braking. If you want bicycle efficiency aerodynamics are where it’s at. At 14mph/22.6kph 70% of your energy goes to air friction and it gets exponentially worse as speeds increase. The real improvements in efficiency are aerodynamics.
@@stefhirsch6922 you're right for flat riding, but it's a completely different story in the mountains. On a steep mountain descent, you lose a large amount of energy with little advantage - a bit of a thrill, but not actually much time saved relatively speaking, if the next climb is a
@@leftaroundabout ebikes with regen braking that are used without power assistance are worse than riding a bike with a flat tire. They just aren’t good and don’t work. So lots of extra drag, significantly reduced efficiency and greater weight are not your friend when climbing steep hills. Extra fitness, easier gearing and standard electric power assist (or gas) are all strategies which work. A system with at best a 58% efficiency compared to 98% displays a clear winner. That translates to a 42% loss vs a 2% loss. A system which is 21x less efficient, significantly heavier and more expensive doesn’t seem like a performance upgrade to me. Until generators and batteries/charging systems are significantly more efficient regenerative braking is a crap idea. The juice isn’t worth the squeeze. Bicycles haven’t changed much in the past 130+ years for a reason (unless we are talking about aerodynamic fairings or recumbent bikes). They work. Lever driven propulsion vs a crankset which rotates the pedals in a circular motion to transfer the power through a chain or drive belt to the rear wheel are the most reliable, durable and efficient that have ever been attempted. Diamond frame configurations rule bike designs now as they did for over a century - they are the strongest, best handling, lightest… that have been tried. The bicycle is the most efficient method of transportation due to its intelligent elegant design. Replacing an incredibly efficient, lightweight and durable design for a Rube Goldberg abomination isn’t progress. Seriously when adding bearing drag from the rear hub, pedals and bottom bracket to the frictional losses to a chain drivetrain would still be 96-97% efficient. A car will have over double that amount.
@@stefhirsch6922 perhaps _some_ e-bikes have more drag than a flat tyre... but that's because they're bad e-bikes, not because they have regen braking. Many especially of the cheaper models seem to be based on industrial motor designs, where price and longevity have priority before efficiency and weight - the exact opposite of what you get with performance bike components. Electric motors, even powerful ones, can run with very little friction. A bigger problem is the torque required, which generally necessitates a gearbox, and again these are often way less efficient as they could be. In principle this could be replaced by an encased belt- or chain reduction, and then you would get the same efficiency advantages of mechanical drive trains. Or even just a better dimensioned / better tolerance / better lubricated gearbox. FWIW, even my cheap e-scooter has regen braking and still coast decently with the electrics shut off. The actual problem is that it's cheaper for the manufacturers to put a freewheel after the gearbox and compensate for losses of the electric drive with a bigger battery, than to optimise the system to be good at regen braking, and most e-bike buyers evidently don't care either, since they anyway charge the bike from the wall plug after every ride. I quite agree that mechanical bikes are great and I won't buy an e-bike any time soon - but they do have two things that keep annoying me: *1.* derailleur drivetrains are a maintenance nightmare, especially in cold, wet climates, especially if (like me) you like to ride in mud or on salted winter roads *2.* mechanical brakes are a bit sad, not only wasting all that energy you've preciously laboured on the way up, but also wearing out in the process. (And, they too are a bit temperamental, with dirt/oil contamination ruining the response.) So _if_ I were to buy an e-bike, it would have to have properly working regen braking too.
@@leftaroundabout most of the maintenance issues with externals drivetrains and derailleurs are A. contamination and B. lack of lubrication. Try fully degreasing your chain (yes it requires removing it from your bike and either putting it into a plastic tub with degreaser and shaking vigorously for a minute or an ultrasonic cleaner with degreaser, rinsing blowing it clean with a compressor nozzle and relubricating with a better lubricant. Ive had good luck with “dumonde tech lite” lube - follow the instructions exactly. For shift wire housing middle burn cable oilers are a great option. For rim brakes in the wet I recommend koolstop brake pads (black for dry, dual compound for mixed conditions and salmon/orange for wet). For disc brakes semi metallic are going to last longer. Try out galfer brand, swissstop, or koolstop. Most brake pads are typically “organic” or resin which are quieter but don’t last as long or stop as well. *Good* mechanical or even rim brakes which are set up properly stop just fine. I’m a fan of shimano bike parts but their brake pads for rim brakes kinda suck. If I bought a new bike with shimano rim brakes I would immediately take them off and throw them in the trash. They wear out rims and don’t stop well while wearing out quick.
I think the two main problems are efficiency (obviously you addressed this), and everyone's familiarization with chain bikes. If they change the concept to having you control the motor with a hand throttle like a motorcycle, I think it would help because then people could auto-pilot pedaling and focus speed control to their hand, an entirely different limb, eliminating the coordination issues and eliminating the need for fake gears since speed would be controlled independently of pedal speed
Bicycle drive trains using chains or belts are 95%+ efficient. This means, our high torque but limited power legs do not need to work hard to propel the bicycle forward. Any gear mechanism or electrical generator/motor system added to the system between our legs and the pedals connected to the wheels, reduces the efficiency well below the 95%+ efficiency of the chain or belt direct drive. This means, it feels harder when pedaling to go the same speed. Digital drive doesn't sit right with me. Let me know what you think.
The main application may be heavy cargo E bikes, where most of the used power don't come from the rider anyways. It eliminates the need of having a direct chain connection, which gives more design freedom and eliminates the need of having a differential on a cargo bike with 2 rear wheels. On a normal bike the only advantage is less maintenance, which is "paid" with less efficiency. I think the Twike (a hybrid between a small car and a bike) used such a system long ago
I can't see it ever hitting efficiency needed to replace a conventional drive (whether chain, belt, or crankshaft) on a bike without an additional power source, but on electrically assisted bikes it can start to make sense, particularly on cargo bikes where not having a chain may enable interesting geometries or allow more cargo space. Even if most of the power is coming from the battery, I feel there's something about pedaling to control your speed that gives you a connection to the road that cars and motorbikes (and bicycles with throttles) lack.
I freak out every time you call it "digital" drive. Electric drive would be better fitting because the concept sticks out for using electrons instead of chain to transfer energy. The controller is just there to increase efficiency. About efficiency: 80% is pretty low for a motor, there are standards for motor efficiency that go up to 97% and beyond. I don't know how well that number can be maintained with variable rpm thougt. Also, 10% transfer losses are a bit conservative and could be improved upon. One solution we might see is two motors front and back: One more for torque, one for speed, both for 4wd-equivalent better tracktion and reduced wear on tyres. Brake usage and wear is also greatly reduced, I guess it should be ok to shave the rear brake of and just have a (smaller, lighter) front brake. With optimisations to the frame the weight penalty will likely be reduced further.
The motor driving the wheel could be up to 90% efficient. Most of the loss will be on the generation side. That motor is going to have a lot of loss from the variability of the rpm. Efficiency in generators drops off exponentially the further away you are from its peak power output. Then once you add on the transmission losses that 60% is bang on what you would expect. Obviously you could improve that slightly, but don't expect anything more than a few percent.
Do you want to work twice as much on a bike, than this electric (not digital) drivetrain seems perfect for you! The efficiency of an electric motor is about 80%. The efficiency of the generator is about 60%. Thus only 48% of the energy can be used to accelerate. In comparison the mechanical efficiency of a bike is about 99%.
Bafang have recently released a 3-speed hub motor with automatic shifting, which might be a good fit for a digital bicycle. As long as bicycles don't exceed 30 km/h in the city, and are compact, quiet, and safe for people around them, I don't really care how they're powered. But I also like the idea of compulsory workout a bit. Nice video!
People will always find ways to make them go faster. Like, when the Bosch smart system came out, it didn't even take a week to find speedboxes for it. Fair point, though, they should be locked when they're delivered, and will be for sure. Countries wouldn't give the green light otherwise
Based on your informative video, I fully expect that the digital ebikes will be in production, and will have a really important place in our cycling world. I feel that it will be a long time however due to cost and development, before there is a significant advancement in expansion market share for the digital ebikes, but give all of obstacles, there is enough positives to succeed, and I would greatly consider owning one, as long as cost and weight are controlled so that the senior population can afford, and handle the weight of such a bike. The cost and weight are now and important for myself and my wife in those areas. Based this video, I feel that the greatest benefit may be the physical therapy aspects, as well regenerative health care as a side benefit from an enjoyable exercise experience. AWESOME VIDEO!!!! Keep them coming!
The real reason why you won't see it in production anytime soon is bike laws. These bikes would simply have to be too slow to be legal without a moped license. A shame because these bikes would offer a smoother ride than any other bike.
@@colin1780 losing the front is a guaranteed fall with rear drive. with front - not so much, you just push on the gas and regain control. have you tried riding any front wheel driven two-wheeler?
@@swancrunch i work in a bike shop and front wheel motor driven bikes are known to be less stable. Going on ice or losing grip will mean that all your weight will fall to the front. Rear will most likely just make you drift a little
If you could dial a pedal load in like a turbo trainer I think it could be very good. You could set the pedal load at say 150w and then use the battery to drive the bike.
I think, that's exactly what this thing do. NOnetheless, it adds complexity compared to a normal chaingear (or belt gear), and reduce hugely efficiency. It's useless.
what could be the efficiency of a well designed hydraulic drive ? with dual pistons driven by the pedal crank and similar arrangement at the wheel, perhaps with 4 pistons instead of 2. and gearing could be infinitely variable by mechanically automatically varying the conrod length. a small lever could vary the amount of effort you want to put into peddling and your speed would be automatically adjusted accordingly. as hydraulic drive ticks the boxes of lightweight, reliable, self lubricating , fully enclosed, and cheap to produce.
Hydraulic drive efficiency are generally also around 50/60%, and that's with turbines. Should be checked for such a small device, but counting this could have been used anytime in the past 200 years and is not a currently known popular method, I guess the results are not very good.
Yay! Recumbent bikes without a long, heavy, dirty chain would be great. Also, correct me if I'm wrong, the first chain drive bikes were less efficient than the latest models. Hundreds of years and thousands of little improvements here and there and we've got some really amazing chain drive options. The more people use electric drive over hundreds of years and thousands of little improvements, it could be amazing. Keep up the good work.
I don't think I have hundreds of years to wait for all of that to go down. It's probably a lost cause tbh. I can't imagine anything close to one to one transmission happening without some kind of clarketech being involved. Gotta admit it's a clean looking setup. I could see motorcycle guys eating this up if the efficiency was better.
mechanical drivetrains are far better than any kind of electrical drivetrain. why are we making these costly drivetrains when we have something that already works better anyway?
![BRASIL vs. URUGUAY [1-1] | RESUMEN | ELIMINATORIAS SUDAMERICANAS | FECHA 12](http://i.ytimg.com/vi/-hWBAuxF1eY/mqdefault.jpg)
I might be wrong... but I think this is the FIRST video explaining digital drive bicycles on RUclips!! How cool is that?! 😎
Viral 🤞
A bit more than pretty cool. But the power efficiency of the digital drive is not cool at all...
@@paulbizard3493
True. It's hard to achieve as much as 70% efficiency, but this doesn't matter. On the flat, the needed power output is low anyways, and on hilly terrain, an electric powertrain will recharge and give back 70% of the energy while with a mechanical drivetrain the energy will go to waste. With an energy bank of a couple of kWh, it should be the better choice for most trips.
Thanks, I was curious about this.
One point you have shown but IMO not put enough emphasis on.
With this you can easily divide power output between multiple wheels (especially interesting for 3+ wheeled vehicles). You can also easily power a steered wheel (I presume that is what gives the cargo bike around 9.30 that amazing maneuverability).
Keep up the good work
Electrom Light Electric Vehicle must have been a part of this video. There is a RUclips channel on how that guy creates and the every improvements he makes.
I need to point out that not everything that involves electricity is “digital”. This is an ELECTRIC drivetrain.
I was screaming internally the entire time. "Digital"means of or relating to numerical digits or fingers. It has nothing to do with methods of power generation.
& this is objectively analog right? Unless it’s just a computer recording your break intensity & directing an equivalent level of power from the battery, with no direct, variable, connection between pedals & engine.
Right. I thought who came up with calling this "digital". There's nothing digital about it. Whoever thought to call it digital needs to learn its meaning.
Yes this is a series hybrid drive. The electronic control is digitally implemented but that is not essential to the concept. An annoying name.
@@yerald_a from the description there is definitely a computer involved. The pedals are just a dynamo for charging up the battery.
What a great concept~ You can get double the cardio for half the distance traveled!
almost as good as an indoor excercise bike!
@@Padlock_Steve you missed the joke so badly it's not even funny
@@Padlock_Steve It's genuinely dangerous to use bikes for travel here. I've had two different cyclists die close to places I've lived because they got hit by cars. Bikes in the U.S(at least in the south) are something you take to trails or parks.
What i thought....cannot be efficient or we would be all using it already
@@robertcowher I can’t stress enough that there are LOADS of US cities that heavily emphasize bike use
Given how inefficient the drivetrain is, you might as well skip the pedals and call it a motorcycle! The pedaling is just to qualify as a pedelec for legal purposes, while the battery and motor does almost all the work.
Remember, that efficiency of 95% for derailleur bikes is fresh out of the workshop. Drive it for a week/month in bad weather and things change. This might not be the right thing for a peak performance bike that gets constant maintenance. But think about a commuter bike, that gets serviced once/twice a year the story is quite different.
@@etherealicer True, but I don't think it ever drops below 90%, even for a really dirty chain and worn teeth. 58% efficiency really is terrible, and that's not even accounting for the extra weight.
Still, it probably has a niche somewhere. Public electric bikes schemes seems like a good use case
@@jackroutledge352 It also is not accounting for recuperation.
I don't know the numbers (and a quick google search I did has not revealed anything). For me, I can see about 10% loss of speed* (though a good part also comes from poor tire pressure) and I do pretty regular maintenance (oiling / pumping up the tires). I do annual oil change on my rohloff speed hub, as it is combined with more thorough maintenance which usually results in 15-20% better speed.
* I daily commute for 2.6km in any weather.
@@jackroutledge352 The day I do my maintenance, my bike is usually in better shape than the average commuter bike (But I'm also pushing it going roughly 30km/h top speed, not bad for an 18kg steel mule). No idea how these losses translate to efficiency, but I think there is a quite significant loss.
Of course this is very hypothetical and anecdotal. Really curious about actual every day efficiency of bikes.
@@etherealicer the efficiency of an external chain bicycle drivetrain with a high quality chain with the right lubricant, clean, fresh… is a little over 98%. Dirt, wear, poor lubrication… do lower this but in poor conditions typically stay well above 90% for a bicycles’ chain drivetrain. There is no comparison between a digital drive and chain bicycle drivetrain in efficiency. A 58% efficiency rating is abysmal - think 1-1.5 flat tires for something significantly heavier that costs more. A high torque electric motor is heavy due to copper and copper is expensive. Besides a good mechanical system is typically more durable/longer lasting than a digital electronic version. Hand crank car windows will typically perform without any needed maintenance or parts replacement whereas electric windows will be needing multiple maintenance services and a few parts replaced. The simpler option is typically going to be the more durable and efficient. Digital drive bicycles only come close to being a good choice when talking about e-bikes. Will future innovations possibly change that? Yes. That said in 1890 bicycles featured a diamond shaped frame based around hollow tubing, power went to the rear wheel based on a chain, wheels were made with tensioned wire spokes and featured air filled rubber tires. The best bicycles today typically have the same features. Yes some bikes will have a belt drive. So magical game changing innovations can happen but don’t count on them in our lifetimes. Given the poor execution of many “innovations“ that I see in newer bikes I dread actual changes. Frames are commonly out of alignment, poor welds, poorly aligned bearing raced, sloppy tolerances… are typical issues with new bikes. So if a drive system which looses 21x more energy, requires the bicycle to be significantly heavier while being more expensive and most likely harder to work on is something which sounds like an amazing innovation to you and deserving your money than go for it. Yes 21x more energy 98% vs 58% or 2% vs 42% loss.
could be a vice versa promo vid:
"now we can use chain drives!- they have almost double the efficency than our regular digital(actually not digital) drives. They are lighter, cheaper, easier to manufacture and everybody can repair them themselves and you will NEVER have to charge them!.... what a time to be alive!!"
Crazy what we can do with modern technology
I'm sold!
Wait until they add solar panel 😂😂😂
They forgot you need a motor at the front for regen while breaking.
glad I dont have to make this comment...
so much stuff feels like two steps back to be able to sell one step forward again.
The electrical loss is so much greater here and would be super underpowered compared to the pedaling being done
A man of culture
This needs to be upvoted.
Exactly, as an Engineer .. this idea of absolutely STUPID. But could make some sense for a plug in battery powered bike that would occasionally be pedaled.
Age! For those not as young... Could utilize, operate, and actually be able to do...
@@KrustyKlown ok so this is what i dont get then. Mr engineer, why is it that diesel eletric on trains exist? Ik, i also dont get how it is better than a drivetrain but its like the only way they do it. How come?
Omg it would be incredibly hard to drive such a bike with so much energy loss! Imagine how much more pleasant it would be to switch back to a normal bike and immediately discover your strength can propel you so much faster and easier! I can't see why anyone would accept lower energy efficiency. Battery power assist is what people want.
Exactly. A clean chain is 98% effective.
A great electric motor is 90-ish %, plus the generator at your feet, making a total efficiency of what, 80% in near ideal conditions? No one would want to ride a bike with a chain that only got 80% because it would feel like a brick.
I would accept it if it had 80% efficiency
@@tarsvanhoof3766 Especially going uphills with your heavy load won't work on a electric motor but on a chain which your strength matters a lot.
@@tarsvanhoof3766 its actually much less efficient than 80%, closer to 60%. would never be adopted in my opinion.
One thing where it excel is on going uphill. The pedaling is generally the same, so you don't have to exert yourself.
I'm working on a far better breakthrough in bicycles: A hand crank, attached to a generator, that charges a battery, that powers an electric burner, that boils water to produce steam, that is channeled into a turbine, that spins a generator, that charges up a battery, that powers a light, that shines on a greenhouse, that grows lettuce, that's fed to rabbits, that run on large hamster wheels, that are mounted on the rear rack, and connected to your rear hub via belt drive. There's a basket on the front of the bike that holds the lettuce that you feed to the rabbits as you cruise along. It's not quite as efficient as a chain drive, but you don't have to worry about grease.
😅🐰💩
efficiency = 10^-10
Are you looking fpor sponsorship? I'm all in.
😂😂😂😂😂😂😂
😂😂😂😂😂
Another benefit: AWD bike with traction control (for commute in slippery snowy conditions). Also front and rear motors may be optimized for different speed/torque.
I think an AWD ebike would be a very very interesting thing to handle obstacles with. You could climb a lot of obstacles with some watts pulling you up by the front wheel!
There is no benefits in such system if you lost 50% of energy into generator and then again in motor.
cycling on ice / sand perhaps
Combine AWD with traction control and fat tyres and you end up with a bike that can ride in the sand. Aka beach bike.
@@bobsnabby2298 50% loss is too much, but 20-30% would be fine, having in mind this has benefit for e-bikes, not traditional ones
Because of weight and simplicity, I think a basic pedal assist system is going to be the best choice for a while.
The conventional systems have been refined over many innovations and iterations for many decades. Bikes today are surprisingly more efficient and better than the bikes we rode as kids.
But electric-powered and electric-assisted bikes will always appeal to people who lack strength and endurance.
@@pwnmeisterage very true
Also they cost more and r not worth it anymore
I think you hit the nail on the head. I have made 2 electric bikes from kits and bought one prefab model. I could see this design excelling for those who just city cruise or easy trail riding which could also easily be done with existing chain drive pedal assist. Nevertheless, it’s an interesting concept.
@@pwnmeisterage or are just plain lazy
Personally I would just put the hub motor at the pedals.
Great video! I built my first digital drive trike in 1986 and dismissed it because it only showed about 50% efficiency. Things haven't changed too much.
Capacitor instead of battery?
things did change A LOT. but yes it will never come on a level of a chain drive.
@@jebise1126 you cant know that
😕 ~30% increase in efficiency is not to bad considering there is barely any market for this tech.
Sorry, I got through about 5 minutes and lost interest. I could make a more efficient digital drive in my sleep.
Absolutely greatest way to complicate things unnecessarily, and to hike up the bicycle prices!
Takes a moron to make something more complicated, takes a genius to make something simple
-idk who said it
Things often get more expensive and complicated to start with, then when they're at the mass market stage they're cheaper than the alternative - I see this being one of those. If it catches on it will end up being significantly cheaper due to the types of parts and engineering tolerances required vs the current chains and cogs.
You mean like technology? Can you name any tech that isn't more complicated?
@@krane15 But technology is supposted to give us benefits. Like the bulb over the candle. This gives no real advantages. Single speed bike, even not geared specificaly for the rider and conditions is going to be better.
@@M_Jaggard You really think bicycle chain has more precise manufacturing tolerances than generator or electric motor..? Or that one day a simple chain will be more expensive to manufacture than an electric motor or generator..?
love my shiny chain, the chain sound, the shifting sound. Bring a chain break and you will always get home if the rear derailleur gets wrecked...shorten the chain and make a single gear to ride home. I also still drive a 5 spd car ...love it, its perfect. Whats the cost of fixing a digital drive , whats the reliability? Can I fix it myself out on the road ? Exactly...no thanks.
The use of the word "digital" is 100% wrong in this context. What you mean is electrical.
He got his millions of views out of us idiots, so who cares.
At.least they didn't call it a smart bike
Well, maybe if it uses a synchronous motor with a square tooth wave DC pulse width modulated generated power signal off the crank? 🤣🤣🤣🤣🤣
Could aaaaaaaaalmost call that a binary signal….
Baahahahahahaha
It just sends a constant 101010101010101010101010101010101010101010101010101 🤣🤣🤣
A bicycle with digitally controlled fully electric drivetrain. I think "electric drivetrain bike" would have been a much better name used in this video.
On a normal bicycle you don't have to push through the dead spots of the crank rotation at all. You can also pedal harder with one foot than the other. Pedal resistance on a chain drive bicycle is infinitely variable at any time without needing settings, you only push when you want to, and if you don't push, you can still keep rotating the pedals.
Also you could have a strap on the pedal of your good leg to help the other.
This is still an energy-consuming process because you are not fully relaxed during pedal rotation. Digital bicycles could provide a more efficient way to spend your energy rotating pedals. Personally, I think the efficiency could achieve 90-95% with the right digital control system.
@@gguy156 On a digital drivetrain you still have to rotate through the dead spot, so where is the advantage?
@@Anonymous-sb9rr You could adjust circuit to charge capacitors/battery when inertia push your bycicle forward. If the current flow is adjusted right you won't feel the difference in applying force. Also some energy of bicycle could be applied to decrease pedal resistance for more smooth pedalling. Like the narrator said, technology is more suitable for electric vehicles with batteries.
@@gguy156 Putting regenerative braking on an electric bicycle that still has a chain, would have the same result.
I like the digital drive for a commuter bike. Nothing will ever replace the standard bike for fun or efficiency.
I actually doubt the speed that it can get to for commuting in some areas
If it is only 25 kph then you won't be able to get into roads
True! Agreed! Btw, if you're riding you should get an nta helmet like xnito or bern hudson, cpsc helmets aren't really safe
Great video. I can definitely see this being useful for electric bikes, particularly applications like delivery bikes. The efficiency will need to improve a lot for it to be serious competition to conventional drivetrain.
At this point, just get an electric moped to commute, this digital drive system seems just like a legal technicality to get electric cars and light trucks into bike lanes.
Replace the standard bike? Well except the ebike! 😉🤣
I LOVE the idea of a bicycle that becomes entirely useless when the motor dies. It's such a neat novelty~
This is a bit of a flawed stance isn't it? Most parts on a normal bike are required for its operation too. If your chain fails, or your gears fail, your normal bike would be pretty useless as well.
There is something to be said for not overcomplicating an elegant design, tho.
This digital drive system currently seems to have significant wdisadvantages in comparison to the old system, but both have many single points of failure. One could probably argue that the digital drive one has more redundancies than a normal bike, as it could use motor braking when normal brakes fail. Or that it could run without the generator pedals for a while if there is juice in the battery.
@@MrJoerT Sorry I don't subscribe to the idea that adding electronics/electricity to proved design is a step in the right direction. 50 years down the line a regular bike may still be operational, this: without an industry to produce replacement parts, you can kiss it goodbye. I like my gear resilient, not fancy.
@@neobscura Fair enough. 🙂
Just buy an electric motorcycle😂 no stupid pedaling😂
@@jasmijnariel What about AN ELECTRIC MOPED. Huh ?! BEST OF WORST WORLDS !
The best use of this would be a 2wd otherwise nah. What I could accept is a super capacitor that charges at regen and discharges to the hub motor at maybe 100w maximum as a "KERS" variant instead of a full electric bike. would make sense in a city environment with a lot of stop and go. And the super capacitor would be integrated in the frame as it does not need external charging.
When can u have it ready?
@@fastinradfordable Depends what youre willing to pay, R&D and prototypes are costly!
A 2WD bike with this technology would be even worse, it would be less efficient, more heavy, and would take twice the effort to pedal because there is twice the number of motors.
@@theyeetus1428 Yes I know, but other than an extreme case where you actually need 2wd, I dont see a point of this type at all, as a 1wd setup it just doesnt have enough advantage vs standard way. But there is no other solution for 2wd so that is the only viable application.
Great idea, and then when your battery runs out you can use you can pedal like crazy to compensate for the huge losses in the system.
Just keep using a chain, it's what you need in a bike.
It's already twice as hard to ride an electric bike with a flat battery with a chain without more power loss.
And what about AWD bike?
Here I see good chance to make pedal drive AWD bike
@@davidmowbray4230 My e-bike has a ratchet mechanism to automatically engage and disengage the motor, so there is basically no additional resistance when pedalling unassisted. Isn't every e-bike like that?
@@StefanReich they're just heavier. Regen brakes would be good for getting some energy back but i'd use a solar panel on the back before pedaling to generate electricity.
@@skirnir-atf they used to make electric bikes with the assisting motor in the front wheel, making them essentially awd bikes. They mostly don't exist anymore, because it's not comfortable nor safe to have too much weight in the front wheel, and because a bicycle with a driven front wheel is dangerous. If the front wheel loses grip you almost always fall down, and if it's slippery out a driven front wheel loses grip easily.
Nowadays you pretty much only see rear hub motors and middle motors.
I can see this system being more popular on Velomobiles due to the more complicated chain setups those seem to have. There's a recumbant or two that uses it too, but they're made-to-order things.
Yes! I was thinking this could be great for recumbent ebikes. They otherwise need *really* long chains - with extra cogs to guide them - and belt drives aren't suitable
I ride a trike and I'm not terribly interested in switching to a drive train that is heavier, less efficient, more expensive and can't be fixed DIY in the field. It might be a good option for people who need an electric assist due to limited mobility or elderly folks but that's about it. I tend to do pretty long rides (50+ miles) and I highly value the capability to fix nearly any mechanical problem roadside. Just knowing that I will be stranded if something goes wrong with my drive system is enough to turn me off from switching to a 'digital drive'.
This could be a great solution as a regen/Top-up for an E-Bike, but not as a replacement for a direct drive (like a chain or belt) on a regular bicycle.
The one big feature missing from E-Bikes is regen braking. This at least would give you the option to add a few watt/Hours to the battery on easy sections of a ride.
The slight gain would hardly be worth the cost or added complexity.
regen braking is available on conventional e-bikes
There is a fair amount of slow speed balance and control that is "felt" through a physical connection between the drive wheel and the crank also. I would like to try riding one of these to feel the difference
That's the digital part. Establishing that bridge.
@@MidwestFarmToys Low speed balance. Above about 2 kph I couldn't care less about a non direct link between my feet and the rear wheel, but below this speed you actually rely on forward thrust to keep balance.
If you had a unicycle powered like this, it would be unrideable.
There is a mechanical relationship with this and bicycles
@@MidwestFarmToys It not a problem at all. Unless your consider advancements in technology a problem. It is the nature of all thing to evolve or advance unless you're a Luddite and want to remain in the dark ages. This is just another possible step forward in bicycle evolution.
@@AJ-oj5eu telll us you've never had your feet tied down to your pedals without saying it.
@@MidwestFarmToys yes I agree, converting mechanical energy into electrical and back to mechanical again, is overly complicating a simple design and to me seems..... excessive.
Mid you I'll argue that an automatic transmission is bordering on extravagance too.
I can see the advantages, much like electrical cars, it has the best potential in a city with lots of stop and go for regenerative braking, and a relatively low top speed. The concept is interesting, and I'd love to see where it goes. To an extent, I can see hooking your bike to an external battery.
regenerative braking only recovers 5% (10% max) of the braking energy or so due to the inefficient generator that recovers the waste energy
could you pedal while driving slow and when the battery is charged a bit drive without pedaling?
That is poppycock.@@davebing11
Interesting concept, however calling it "digital drive" is quite the misnomer - the signal doesn't need to be digital (0/1) here, it can be analog as well.
The grand difference is that the power is transferred by electricity, not mechanical movement, therefore the name should reflect that.
It is always analog. You can't drive a motor digitally. The name digital drive makes zero sense. Its just an e-bike that removes the chain.
@@xe-wf5iv I disagree - driving a motor via PWM would qualify as running it digitally in my mind, and technically you could PWM the generator side as well. Not a big fan of the naming, since I doubt it will always be PWM though, hence my original comment.
@@Ox4C4A No, PWM is analog, because PWM does not represent a numerical (digital) value. The fact that the signal has 2 signal levels, does not mean it is digital.
Furthermore, the duty cycle of a PWM signal has an infinite number of steps between 0 and 100% if you generate it witih a common PWM driver, like an NE555 for instance.
You can, however, convert a digital signal (such as the output from a digital RPM counter of the pedals) into an analog PWM signal to proportionally send drive energy to the wheel motor. In that case, there will only be as many duty cycle values as the number of binary bits you reserve to represent the power level. All the processing to control and generate the PWM signal, are digital in any modern vehicle.
There is an exception: somewhere in the 1980s, some smart guys developed a way to encode bytes of data in such a way that they would form a correct PWM signal, but also actually represent bytes of data that you can feed straight into computer memory or disk storage. They used this to digitally record analog music cassettes. The natural lowpass characteristic of the tape recording heads ensured that what got onto the tape wasn't the raw PWM signal, but a smoothed out normal analog signal.
At least that's what i remember from that article. It's very interesting, worth trying to look up if you enjoy early computer tech.
When I was commuting daily by bike as a student, my yearly maintenance costs were less than 150 euros (most of that was a yearly service by a mechanic). That is insanely cheap for something that I used every day, rain or snow. There is a great strength in the simplicity of the chain drivetrain: it makes it easy to learn how to service it, and straightforward to produce spare parts, you can even learn to do it yourself. Compare that to the nightmare of modern car maintenance, where even software errors can (at least temporarily) brick your car.
If you combine it with an ebike with proper motor controls (including torque sensor), I cannot help but wonder how good a front or all wheel wheel drive would be.
We saw in rallying that all wheel drive was absolutely the way to go for control in difficult circumstances, so it could make sense for bicycles too. I just don't like the ones that do it currently, because the motors are never properly controlled and just go full torque the moment they're activated.
I actually think a torque sensor is the wrong way to go. Why? Because in many situations you want to be able to modulate your speed. If the only way to slow down is to work less, you cannot build up power for that next hill. And if you don't save up, you will fail to make it up that hill. A hand throttle and optimizing your cadence and output you're willing to put in, could allow you ride with almost as much efficiency and certainty as you currently get with a parallel (traditional) pedalec. I think this video started out with the right concerns, that weight and efficiency losses mean we'll continue to use chains and belts.
@@karlInSanDiego You are absolutely correct. I immediately fell back to my "I hate these on normal bikes" mindset when I started thinking about front wheel drive.
I do think they could be quite interesting and possibly advantageous though.
All wheel drive bicycles already exist - and have for decades. Look up christini all wheel drive bicycles. They have more control descending and improved drive traction for climbing. They work. So far the design hasn’t taken off. It doesn’t look like they will anytime soon.
Yupp, but kiss it. Pedals drive generator and charge battery. Battery drives motor. 1 gear , like a Tesla. Gears and chain on an ebike are just plain weird. Huge thanks .
All wheel drive is not needed unless you ride up and down soft sandy beaches. A military combat situation where you need to sprint with a burst of speed would be helpful.
I would like to build a all-wheel drive bike just for off road fun…
I think having a motor to help you speed up from a stop, or while riding uphill, as well as regenerative breaking are a good idea. But I'd make it a hybrid, so that there are both the chain system as well as the motor and a generator, so you get the efficiency of a chain drive, but some advantages of the digital drive.
I heard regenerative drive system is too heavy and expensive to put on a bike. Also it’s not digital!!
@@aaaaaaaard9586 It's not, electric motor can act as a generator too. My previous e-bike had regenerative brakes.
@@digitalspecter It says you need a different type of motor called direct drive motor for regen brake, which is heavier than normal motors. It also adds resistance on pedals, and creates heat when it brakes. All that for around 5% of battery saving.
Those have been around for ages.
@@aaaaaaaard9586 a lot of ebikes have direct drive motors, they're cheaper than mid drive. They're a bit heavier but way more reliable and don't require replacing your chain as often. A big benefit of them is when you're using the regen braking is slows you down without wearing out your break pads.
If you think about, this could allow for front-wheel-drive bikes. Good idea? Bad idea? I don't know but it's certainly interesting to think about.
Most electric scooters are FWD, I don't know if it makes a big difference for commuting as you're never (hopefully) at the limit of traction.
Weight distribution favours rear wheel drive. Body position while peddling will always put more or most of your weight on the rear wheel, so it really does make the most sense to keep the drive power in the back. Similar but opposite to why the front brake is more effective than the rear.
The second disadvantage in a hypothetical front wheel drive bike is if you lay down too much power, you'd lose steering control and could easily lead to the front wheel washing out. Back to the brake comparison, front brake control is a mountain bikers most important skill. Managing that the front brake is capable of the majority of your stopping power when riding downhill, with the risk of locking up the front wheel is an art.
Could there be a use case for 2x2 bikes, where both wheels have power? Possibly, but they'd be few and far between. If riding in low traction environments like snow or gravel, there could be someone out there that would benefit from a front wheel that could deliver power. More so with utility bikes or heavier enclosed bikes like in the video. My 2 cents.
@@sumoneskid possibly a 2x2 could provide the torque needed at a lower motor weight?
Recumbent bikes with FWD do exist but you are creating more problems than solving them. In those cases you either have to sacrifice turning by having a regular steering on front as well or having a reduced turning radius with rear wheel steering.
Pretty sure the first bicycle with pedals were front-wheel drive and they changed the design because they weren't as stable.
idk, adding a batery and motor to a bike sounds like a good idea until you realise that its just a slow motorbike and you don't really need to pedal
It is certainly the first that I've seen. And now I really want to try one; the idea of indoor training which charges a powerwall is just great!
😂 add a bike to grid voltage converter and you could paticipate to your electricity consumption.
What are you going to do cycle 7 hours and produce a kw? Wow you earned yourself 35 cents.
I think the hybrid concept is great; you can control the bike speed independently of your pedaling speed. I could see an athlete commuting to work, really putting in a tough workout, yet his bike is moving at a moderate pace along a busy bike path.
And, of course, you could have it where you're pedaling at a moderate, constant pace, while modulating your bike speed according to traffic conditions.
I've been a fan of the generator/motor/chainless concept for some time now, and this video does a great job of discussing the pluses and minuses of current technology.
Only problem you need to use the energy at somepoint if you generate all the time. Like you need to recharge an e-bike you drain all the time.
You also could partially short circuit the motor and dicipate the effort in heat. But that's kind of a waste.
Also if everybody drives a view watt extra a day for 30min this adds up to an significant amount of power over a year.
You mean, like gears on a normal chaindriven bike?
You've literally described exactly what gears do.
You can't have the energy input constantly greater than the energy output (ignoring drivetrain efficiency).. Even if you had super capacitors or a battery to store additional energy, these would eventually reach a state of maximum charge and you'd be back at square one.
The use case you've described is already achievable with gearing and the addition of a dynamo light or dragging the brakes.
@@MrHaggyy i dont think you can short circuit the motor very long. the energy will go towards heating up the wires. you can short the motor on a resistor though.
@@MrHaggyy i dont's think spending energy is a problem at all. when your battery is full it will just stop charging, and your generator will do nothing.
and i seriously doubt there will be a case of "too much energy" ever.
the biggest problem with independent of your feet controls for speed is, weel, it's independence. you'll need a gas crank on your handlebars and to relearn hardwired "pushing pedals make you go brr". which could take a lot of fun out of the cycling experience.
I thought this when I saw the emergency closing cranks for water tight doors on ships. I used to work in ship building. You simply rotate a crank and two very large cables transfer the electricity generated to the door motor that closes or opens the door depending on the direction. It essentially is the same thing.
I'd also argue that it isn't "digital" it is very analog. Just electric.
The gearing is determined by the coiling. So it will be single speed and that's it. No easy way to have gear in this system.
@@K1989L isn't it pretty easy to control speed of an electric motor tho?
@@K1989L Actually quite digital for the controller driving the motor. For efficiency a synchronous motor is needed which means digital controller has to generate a variable frequency waveform. The controller has to be aware of current speed and current power requirement.
@@K1989L Synchronous motor where the digital controller does all the work. Full time electric cars have no gears. It is all magically done by the digital controller.
I truly appreciate this thorough review of the digital drivetrain for bicycles. What I like most is the fact that when pedaling I would be able to keep the cadence the same regardless of terrain. Also regenerative breaking and recouperation of energy when going downhill is awesome.
Yeah, no... People like you don't seems to understand that electric motors and generators are far from having a perfect efficiency, you'll basically need to force about 2x more to get the same speed as normal bicycle so I'm not sure that's a very good tradeoff just to get a tiny bit of regenerative braking once in a while...
@@Alfred-NeumanElectric motors nowadays, at least ones suitable for this, are over 95% efficient. This goes for both the driving motor and the generator. The motor controller can and usually is over 93% efficient, up to 97% efficient.
This is literally more efficient than belt drive.
Make it recumbent and enclosed, and it would be way better (faster) than a usual bike, more efficient at speed, and with a small battery, better overall for commutes.
@@vladlu6362 But is it worth sacrificing repairability ? Especially when there is a lot less data on the reliability of this technology. On my cheap bike if something breaks I can fix it myself in less than an hour for pretty cheap. If the motor or generator breaks, it's gonna be an expensive repair if it's even possible.
Great video! The use case I have always thought this would be best for is an e-bike recumbent because regular recumbents have to have super-long chains to get all the way from the crank back to the back wheel which are kind of annoying. "Digital" bikes will have lots of fancy electronics but really you just need two dials: how much crank resistance you want and how fast you want to go; and something to tell you the range you have left given what you have set those two dials to.
Agree, for a recumbent it really would be a big advantage. The aero advantages would compensate for the inefficiency, the power transfer wouldn't be nearly as tricky as a mechanical recumbent (thus the relative weight penalty is less than in the upright case), you could easily add rear suspension which is a big boon for recumbent, and the electric drive makes the startup less daunting.
Electom is a company in Canada making recumbent, digital drive e-bikes. The channel Fort9 made a video about it some months ago.
@@max-zv7sf I think you mean Electrom.
This is the first such a comprehensive video on digital drives, congrats. Think there is a great future in it, with further tech advancements. One special drive I have recently seen is "Revonte" - a hybrid, stepless automated drive and gearshift - it works like Toyota Prius - and imho it will be a killer drive until digital drives fully mature, with same "software defined platform" benefits as with the digital drive. Can't wait until those bikes hit the production!
Why not just ride a quality 'normal' bike. Adding 'digital' really does nothing but add complexity that is just not needed.
There twitter is abandandonded in 2019 and there recent blogging is not persuasive.... very delayed even channel here is 2021 arguing "artnered with EAV, Lavelle bikes, and Tunturi bikes. "
This will not have "a great future", chains have an efficiency of about 97%. That is insanely high, quite literally nothing compares to it. So it would be really dumb to throw that simple efficiency away
Love the channel. Currently among the most professionally produced content anywhere with well researched detail, stunning visuals and great explanation across the world of cycling. May you continue to enjoy every success.
Jesus chill out, it's decent but this is a pretty amateur voice over ontop of stock footage, no need to make it sound like the Interstellar of cycling content
@@chrisogrady28 Says the nobody with 134 subs...lol
The information seems to be inaccurate.
Fascinating and well made video! Seriously cool....but don't think you slipped that groaner past us at the 4:56 mark. HARRR!!
mighty morphin...
Comprehensively researched and well explained, as always. And I agree with your conclusion: it's not an alternative drive train for unassisted bikes but it will likely displace the mechanical transmission bits on e-bikes.
No it won't. You first...lol.
If you had said 'some bikes', you could be correct. Bikes in general? Not a chance. This is a solution looking for a problem. Bicycles when invented and bicycles in 2022, still the most efficient mode of human powered transportation. Why throw that efficiency out the window?
This will be super duper niche, and ultimately will be a complete failure.
@@joeshmoe7967 the way most people ride it it is quite inefficient, most average people pedal 200W and have the middrives in turbo, and Bosch CX peak at around 700-750W infact, not the "250W" European limit
that means you got 200W pedal power and 700W assistance so 900W total, if you went to this mode it would be like 820W (200W effort but 40% loss, 120W) and the 700W
your consumption wouldn't increase as the power is limited, still a marginal difference in the end.
not only that's great but you'll have the ability to fine-tune the feeling of the pedals, your preferred cadence etc in software as you can vary how much power the pedals generate basically, and you've got none of the issues a normal drivetrain would/could have (derailleur adjustment, chain cleaning, chain skipping, or just no changing gears in general)
it's like having a cvt without a cvt.
@@BH4x0r Yeah and CVTs were a failure too.
@@theyeetus1428 in cars, yes, on ebikes it's just too expensive
in cars the problem is that people want to hear shifting noises, which is retarded in my opinion, why would you pick something less efficient? but whatever
since i've got a bbshd on my ebike i haven't ever shifted as it has a great rpm and power range, it can climb hills and reach 40km/h in gear 3/7 (it's limited to 25km/h cuz of Europe trash rules but it can), but since it's power limited (battery current limit) rather than increasing in power as it goes faster (motor current limit) it's perfect, sort of, more torque and power wouldn't hurt but it's fine at 1500W
electric cars (no shifting) and no-shift ebikes (enough power or cvt) are the best either way.
I mean nobody should want to really slow down cuz of a normal uphill, it makes the ride even more boring
Stunning!
A bicycle chain has an efficiency of about 90%.
The power efficiency of an electric motor as well as the generator Is about 70%. So you have to push twice as hard to get the same power on the wheel. Admittedly you could add battery storage and use the energy of regenerative breaking to the battery. However an efficient generator, motor and Batteries will weigh in at a substantially higher weight than the traditional drive train. So bicycle frames are made out of light weight materials and then we load them up with heavy clutter. I guess someone might say it is a great idea, but apart from playing with new tech, it doesn't make sense on a pushbike.
The economics will probably look better if you add the generator to an electric bike.
Dirty chain has about 90% efficiency so right, drivetrain like in the video is not worth it at all.
You have your body weight and your payload. Couple of kgs won't matter for many people, unless you want to do a race.
Bravo
70% is not half of 90%, this statement alone should be reason enough to not take you seriously. The rest is also just guesses, not even educated ones. I’m so tired of people playing experts on things they have watched a single RUclips video on.
@@foximacentauri7891 so nice to be fast checked. If have taken my numbers out of my old electronics reference book. Please share YOUR sources and explain how a bicycle chain manages 30% energy loss.
Then we can see who can be taken seriously.
the idea is simple: take what can work for 200 years and make it work until the next update
That is what people said when others put chains and pedals on their walking bikes😉
In all seriousness. No drive-train lasts that long without maintenance and parts-replacement (unless you don't use it).
True, yet anyone that can handle a brush, spray cleaner and lube can do maintenance.
@@jedibusiness789 The kind of maintenance that is not required in a system like this (well, you still have to maintain your tire pressure).
I'm talking about replacing the chain/cassette/derailleur(s)/chain-ring(s)/gear-cables and then adjusting it, so the gears change properly again.
There are really only 2 components that will break on an e-bike (from the e-drive, commonly it is actually the chain/derailleur part that breaks). Motor controller and of course your cables/connections. Both are easy to fix, they take very little skill and won't cost much (certainly not more than replacing your chain/derailleur). There is pretty much no need for specialized tools (maybe some torx-bits depending on your model, but that is not more special than a chain-breaker).
Longevity and ability to repair is really not a concern. Efficiency is (though it would be really interesting to see a comparison to a bike that has been used for a while and including recuperation).
@@etherealicer If efficiency is important, this dual motor is far away from the solution with over 40% power loss. A normal chain drive bike that has been beat to hell would never lose more than a few percent of efficiency.
I could totally see this style of drive train replacing chain drives on E-bikes. You could even ad a sturdy kickstand and convert it to an exercise bike to charge the battery.
Regen braking on a bike is useful for a mountain decent, but for rolling hills you don't want to curtail downward momentum by using regen braking. It's why almost no one in the e-bike world bothers. You rarely want that effect, and it's also got an efficiency loss.
I appreciate this primer. Too often people assume it's an obvious evolution of bikes. but that weight and efficiency penalty are not worth it in most instances. The Podbike, Arcimoto Mean Lean Machine, and some other velomobile type startups are using indirect series electric drive too. These rely on big batteries to make up for the fact that you're losing so much efficiency to the double conversion at the same time that you've encumbered yourself with much more vehicle weight.
will be probable the regen work with an special brake lever or adapter that will works with brakes with some adjusting. so instead fadding brakes on reductions the regen act and when you need power the brakes act. this will be increase the pads durability and range to modulate. but the cost and weight is the problem
WTH are you talking about?
Regen braking is activated just like braking.
Regen braking has nothing to do with chainless drivetrain.
You just need a hub motor without freewheel.
I have regen on my e-bike.
There is a contact on my brake lever, and then I choose the braking intensity with the accelerator.
In a city environement (Paris), when I use regen as much as possible, I get 15% of my energy back. 10% when I'm not really into it.
In mountainous environement, you get around 30% back.
What's great about regen, is that you wear your brake way less (like with EV's), that mean way less maintnance on the bike, that the biggest argument for regen.
About the chainless drivetrain, I'm on par with you.
Having 2 engines instead of one + a belt system for example, is way more fragile and complex.
If your electronic fails, you can't move anymore, with a physical drive train, your bike is still a bike.
If your bike is not an ebike, then this whole concept is total nonsense. Nothing can compete with a chain drive. But if you have an e-bike anyway, then maybe it could make sense. But having, essentially, two motors will be a disadvantage.
I think I'd always rather have a pedal assist e-bike with a regular chain.
The chainless electric bike seems like a novelty that exchanges efficiency for some cool factor. Which granted some of them do look cool and futuristic.
An ebike with regenerative braking to me seems like the best path forward for bikes.
Or just ride something cheap and human powered that won't get stolen, that's probably the most cost effective. Ebikes are already being banned on lots of trails in the US unfortunately, and likely digital fall under that same ban.
ebikes are banned because the battery can allow the bikes to move faster than a normal riders speed. US law regulate then to under 25 mph unassisted but people alter them , thus the ban.
@@danc2014 If they would be similar strict about cars who legally are capable of highway speeds in inner city...
For a regular bike, a mechanical electrically assisted drivetrains makes more sense. But for e-cargo-bikes, this type of drivetrain can be much better than anything chain based.
@@danc2014: I don't know where you're living, but Michigan allows E-bikes on its trails, for the most part.
The way the statutes are written is that an E-bike is restricted in top speed, but for some reason, a human-powered bike isn't? I can get a 26" 21-speed MTB up to 45 mph on flat land, with slight variations on pavement. Which, by the way, is the actual speed limit on some roads around my area.
Point is, I see no point to restricting E-bikes according to motor rating or top speed, when anything below a 11.1 kw power output rating is not allowed on interstate highways and freeways only (i.e., limited-acess highways).
And Interestingly enough, the only type of vehicle whatsoever that's rated at some kind of class are commercial vehicles, based on GVW; number of passengers that can be carried; and number of axles.
Not even cars & trucks are regulated by motor size or horsepower, which discriminates against E-bikes, given that speed limits exist for a reason, and most E-bikes have speedometers. So my question is, why not just simply say, "E-bikes are e-bikes, no matter what the power output is, and the only obligation an e-bike rider has is to adhere to the speed limit of whatever road they're on, and that they are prohibited from all limited-access highways"? The rules for E-bikes just seem arbitrary and discriminatory, is all I am saying.
Been working for diesel trains for over 100 years
Because there’s no mechanical drivetrain that can handle the loads involved. Simplicity always wins.
And weight isn't an issue.
As a tech head this is friggen amazing... As someone who loves the simplicity and the ability to maintain a bike at low cost and low knowledge(as in a car takes way more time to effectively maintain a car than to learn how to completely work on a bike) is in-valuable.. This "evolution" just means normal people can no longer work on their bikes. Imagine you have a 1hr by bike commute and your bike breaks down, whatchu gonna go, call roadside geek squad for a bicycle??
Really interesting stuff. I have to say I don’t like the idea of it not having that quick engagement you get with a physical connection to the back wheel. People who are very casual won’t notice, but it would undoubtedly bother long time riders a lot if it doesn’t feel like what they’re used to.
I’ve seen it already where riders do a few revolutions before a 4-wheel bike van starts to move.
I think the way with this would be like Tesla did with cars. Instead of trying to make it “feel” like a traditional bicycle they should fully lean into the advantages of digital drive and embrace the differences.
@@Noadvantage246 Yeah maybe. I try to always be open minded, so we’ll see.
@@christill I hope some takes this up I think there’s a lot of potential here.
I already got plenty ideas. For example if you had a digital drive bike with an electronic, daul-sided, kickstand; you could create a bike with launch control! The kickstand goes down and you pedal in place building up surge capacitors. Then with something like a thumb throttle you could launch it. The kickstand would retract instantly as the motors spin on full power!
This would be hella fun and kinda funny to go from pedaling in place to taking off like a rocket. But it’d also be practical for commuters. You come to a light and can keep you pace a cadence going then take off back to your pre-set commute speed right away.
well the problem with the 4 wheel bike van you mention is cadence sensing, if it is torque sensing it is instantaneous dependant on controller settings ofcourse
I just came back from Japan after staying away from traveling for about 4 years. Previously in Japan, rather heavy bikes used to carry children were commonplace. This year, 2022, only 4 years later, more than 90% of these bike have become electric. This phenomenon was observed in the Yokohama area most likely due to hills and to the on-time culture. I do not doubt that given a few more years that this new type of digital drive will appear in Japan.
I don't think so, this feels very much reminiscent of the CVT era in cars, in theory it's better but in reality it just doesn't get adopted as much for various reasons (response time, feeling, etc)
Keep the chain but add the digital drive to the front wheel, and synchronize it to the pedaling, that would be an awesome bicycle (at least for me ) able to climb difficult obstacles.
I will say that it'd need a back motor aswell, it just isn't smart to have a lot of power on just the front wheel as it can slip out easily, then 2WD would be better
Front wheel driven electric bicycles already exist, but they are less popular because acceleration feels less natural as you're pulled forward and they make steering more difficult. It's cheaper though than motors at the crankset.
@@Frrk hmm i would disagree with that, a Chinese 500W peak torque sensing middrive will be around €300
a torque sensing bottom bracket for a front or rear wheel motor controller often runs for €80, that is without the controller, motor, wheel etc.
when you're talking about cadence sensing, sure, but even then it's still hard to beat the €300 middrive
@@BH4x0r That does make sense, from a components perspective. I just looked at advice on biking sites where it was claimed.
@@Frrk truthfully most middrives are made by European brands, which also like a large part of the money as profit if ya know what i mean, which is understandable as it's actually very expensive to pay European employee's, atleast in Belgium, The Netherlands, Germany and France, eastern min wages are much lower
for example for the min wage of a few years back in Belgium (€1650 a month) the companies had to pay out €2200 or more to the recipients as the rest goes to the taxes
A bike that comes with an integrated upright stand could also have a mode built in where you could charge the battery while peddling in place. Say if you had a commute that was kind of awful you could still pedal it in a session or two during the day, storing your mechanical energy for the next time you ride but not having to get all of your pedaling in at once. This could similarly have the perk of being able to act as a mobile charging station for smaller electronics using this same idea.
You would always need to pedal a lot more than what you get out
I've designed a similar idea for a pedal generator and battery-powered electric motor-driven Kayak. My system does use digital control for the BLDC motor as they are more efficient than brushed DC motors. The overall idea is simply to extend the battery life.
Maybe there are more advantages: less need for rare earths and less weight (which also results in greater battery life). The downside, is you need to convert the DC battery to an AC current and a more electronically complex control system of the motor torque and velocity.
@@Sergio_Loureiro My design just uses a sensorless BLDC motor for prop and one for generator. I'm not concerned about rare earth magnets. This is just a hobby project for my own use. 3 ph AC is automatically created in the generator but then is rectified to DC for battery charging and the prop motor driver. A pretty simple design. :) Prop motor speed is simple in software. No need for constant torque control in such a system.
Hub to crank radius/ratio could solve some of these uphill issues, and even be great for higher speeds.
you either have speed or you have torque you have to choose one if you dont have multiple gearing to use that or your bike quickly becomes a motorcycle legally
This would be a great candidate for the use of super capacitors as they are lighter and should store plenty enough to get you going at the lights
They also have lower resistance then a battery. So you will see a gain in efficiency.
@@MrHaggyy no, the maximum power transferred is when the load resistance matches the internal resistance, so this would mean max power transfer at a lower load, lower efficiemcy for same load
"super capacitors as they are lighter"
If one compares the amount of power per gram of the two storage solutions (batteries vs super caps), super caps weigh much much more than a battery with comparable energy capacity.
Super capacitors have miniscule power storage compared with batteries. Tom Stanton made a video showing a super cap powered ebike *(Super Capacitor Bike).* It was pretty terrible.
I watched a bit of the video just now (while finding the title) and I see Tom had also built the motor. It's possible with better components a super cap bike would perform better than the one shown by Tom but I doubt it would work well.
If you're going to the trouble of adding a motor and generator to a bike, you'd probably want to use real batteries to maximize the benefits of using an electric drive.
@@locomotive9000This kinda doesn't work when you have a non-linear power supply sitting between the source and load.
The hall effect, in combination with a supercapacitor, can bring up the efficiency of an electric drivetrain to about 80%. It's not as good as a chain, but most people care about getting to the place that they're going instead of having peak efficiency.
The ultimate solution looking for a problem
Ever since I purchased a drive shaft bike years ago I have not been a big fan of chains. The simplicity and reliability of drive shaft renders chain drive obsolete in my view. The concept described in this video is very interesting. I have thought about a similar drive years ago but was under the impression the losses of efficiency would be so great as to make the idea impractical. I see in this video that many of those obstacles are being overcome and that is very exciting. Thank you so much for posting this video.
With a throttle you can pedal at any speed you want and have a smooth ride so I don't think it is a bad trade-off. They spend too much time mimicking conventional bicycles when they could have a easier time building the RollsRoyce of bikes.
Wonder what it would ‘feel’ like as riders get a lot of info via pedals,drivetrains tyres etc. Sound too.
That is only part of the problem.
Great video, but I disagree with the statement that digital drive e-bikes will be better in poor weather - at least in winter conditions like the photo shown as you said that. Battery output drops massively in cold weather, so you could conceivably bike somewhere, park your bike outside, and return to a dead battery a few hours later. Then you'd have to pedal your heavy, battery-equipped bike purely via the inefficient digital drive to get home. I've been driving an electric car for the last seven years, and a cold-soaked battery on a return trip is something I'm very familiar with.
You assumed there is a battery. Could be a capacitor bank.
Thanks for adding the complete pros/cons that so many ignore. Electric transmission (non e-bike), is less efficient and needs a battery and e-bike powered transmission (power delivery) system to really show any promise. But, that is certainly a really cool option. I designed a hybrid bike for an international bike design competition in 2006, so the ideas have been around before the tech was there. I can see a company like Canyon really pushing the future on this front.
One important note to add: Adding electronics and batteries inherently make the bikes far less sustainable due to the increased materials/batteries/maintenance.
And yes, these are specifically electric, but can incorporate digital control.
It is very cool! But aren't you mixing up digital with electrical?
“E-bikes” aka electric bikes already exist. That’s a motor and battery + chain and pedals. These bikes are technically also electric driven but the name is taken so… lol. Plus “digital drive” is a good name for it given the chains and gears that normally drive a bike are gone and “digitized” in a sense.
Great power rangers jump cut!
First of all, this drive system has nothing to do with "digital." It is electric. Second of all, putting a battery on these bikes does not solve the efficiency issue. In fact, it will make it worst as mechanical power from the peddle must first be converted into electrical power and then to chemical power (batteries) and then back to electrical power and then back to mechanical. Adding more and more batteries will only contribute to further increase in weight. In the extreme cases, it is like someone installing a foot peddle generator to charge the batteries on an electric car. (Probably a dumb idea if you think about how much peddling (energy) to get yourself anywhere.) If the design mostly relies on the energy that is stored in the batteries, then it is essentially a batteries powered bike.
"derailleur gears and chains have improved incrementally over a century and have well and truly proven themselves to be lightweight, high-performance, efficient, and cheap to produce."
You said it so well it was almost a poetic endorsement of bicycle chain drive systems that I personally find to be a sweet spot overall ..
Great video! I’ll stick with my chains and belt, but this was great content, as ever! 👌
When i was a young man I was very fit and one of the reasons was that I cycled 30 km each way to and from work.
Having technology do the work for me would make things easier but I would lose most of the benefit of exercise.
I also used to swim 2km and run 10 km per day.....I guess the future will invent something to make this easier as well.
Still, I would love to give this a go, now that I am old and not so mobile.....maybe this could re-invent my passion for exercise that I once had?
try running 10km per day without shoes and then let me know if our technology ruined the experience or improved it
@@janthran as i said, I am now old and not so mobile....so I will not try running 10km per day with or without shoes, because I know I cannot :(
@@Ulbre my point is just that as technology advances, it becomes normalized. you don't even think about shoes as "using technology to make walking easier" but it that's absolutely what they are.
I don't think you got the point. You will still have to pedal this bike. A bike like this with just the generator and motor would not have any more power than what you provide.
@@wimharter I think I totally got the point whereas you totally missed the point of my comment....but hey, you lot are out there!!!!
and regen will be an easy option...love the idea. Combine it with a decent battery to overcome the disadvantages in system losses and you have the ultimate bike imo. I've often thought about this concept and wondered how long it would be before it was put the market.
Add I a capacitor and you can carlect more regenerative energy
You'll never fully overcome those losses though. This will always be a less efficient form of cycling.
I've had an idea for years about putting a system like this in an enclosed recumbent design. you could even out the pedaling intensity so you're not all sweaty commuting to work, plug charge, solar, or use it as a stationary bike to work off lunch and charge system, then pedal as much as you want with a surplus of energy. system like this with a decent battery would afford creature comforts like heat and audio due to reduced range anxiety, allowing people to cycle when they wouldn't due to weather and hilly terrain
Any idea how slow a solar panel charges? A night rider could let the bike charge “over day” I guess. Also need more coal energy to make a solar panel than what coal directly delivers. I am looking for a coal fired bicycle. It is the most “green” of all.
@@jusuftheeagle6772 I was just saying it's an available option, not the be all end all
alas, heaters use crazy amounts of power. A small fan heater would take a couple of roided up Lance Armstrongs to power it
I think a bundle of super-capacitors could be a really cool alternative to a battery as well. Charge them just off the regenerative breaking and have a button on the handle to discharge them one at a time as a "boost" where the bike runs under its own power for a few seconds. Capacitors have a much longer lifetime than a battery and don't suffer the power loss over time or in cold weather. Having several boost charges to help you get up hills or get back up to speed from a stop would be very useful. And so long as you were using your boosts as frequently as you charged them you'd technically be getting that efficiency return from regenerative breaking just the same as a battery. Ofc It would also be very video-gamey in a fun way.
I don't think bicycles typically spend enough time braking to generate enough electricity to do much meaningful work. Especially not one as slow as these would be, given the poor efficiency.
@@tonyb9735 this. the amount of energy that can be recouped via regenerative braking (obviously) correlates to the amount of energy that you waste on braking. with a car this can be significant because in the city traffic, you are bringing 1-2 tonnes of weight to a complete stop from like 30-50km/h all the time. But cycles weigh significantly less and most cyclists ride with a bit of foresight to minimize the braking that is required. on long downhill roads you may be able to collect some energy, but then again on most downhill passages i pedal a bit to get faster instead of constantly braking.
Regen braking is like 15% efficiency often times, whatever that's worth
I especially liked the contraption with the solar panels on it; they would also give some protection from rain and snowstorms. I can only imagine how much fun it would be to ride this thing 15 miles to work during a winter storm in Boston, MA where I live. Thank you for opening my mind to possibilities I never knew existed.
lol
Recumbent trikes. or tadpole trikes/bikes. they are really cool and you can build one yourself :D
Recumbent bike design with a chain/belts has always been a challenge. There will be some neat designs out of this. Though the never spoken about flat tires will still stop wide use.
Great Video! It's interesting your analysis on digital drive bikes is similar to what I found on Electric vs Hybrid vs Gas cars. The gas cars can reign supreme at very specific speeds based on their transmission and on flat terrain with no stops. Hybrids and Electrics both handle the stops as well as down hill sections wonderfully with regenerative breaking. Hybrids are great as some can offer redundancy not often talked about or utilized well helping with major issues since they can essentially have 2 drive trains. Whereas Electrics only have one to deal with and so can reduce complexity. Though not weight since batteries weigh more than gas.
Well done video and I agree with your thoughts about not really practical for regular bikes but very likely a great fit for E-bikes. I’m about 9000 miles into riding a BikeE recumbent with the Grin rear wheel 212 ready to roll kit. Wonderful set up but the chain length and maintenance are my biggest challenge, not to mention that I need a 70 tooth front sprocket to peddle the speeds above 20 mph. I want a generator crank!
Regenerative braking is a nice feature, but nearly all bicycles have a freewheeling rear hub, and that has a lot of advantages, too. Remember that air resistance is a powerful "brake" on a cyclist going downhill at typical speeds. With sufficient regenerative braking, one would have to pedal more, or use the motor. That's one reason few e-bikes have regenerative braking.
I don't think that you'd need to have the regenerative braking active whenever the rider stopped pedalling. It could be controlled, by the rider, with a digital brake lever
@@pedalinpete - Yes, but the less Regen is used, the less value it provides relative to the cost of installing it. At any event, Regen braking should be activated with the brake levers, so the bike can still freewheel. The freewheel hub is one of the most energy efficient parts of a bike, and due to physics, no other vehicle besides a bike and a train roll as far without power.
@@pacificostudios Regen is worth it even if it used battery. Magnetic braking is maintenance free, intrinsically anti locking and works the same in all weather conditions. Also the brake lever feel does not change over time. Bicycle brakes are super annoying to work on and are very high maintenance.
@@difflocktwo - Don't forget that Regen braking cannot actually stop a vehicle because braking force falls to near zero at low speed. Some form of friction brake is needed to actually stop a bike safely, even if that's your foot.
@@pacificostudios You can use a bit of battery to stop. Think about "reverse". Basically you can use battery to drive the motor in reverse to keep braking force high even when it doesn't regenerate. Many shared scooters use battery to lock the wheels if you try to move them.
What if: we left the rear wheel driven directly by the pedals (eliminating conversion from mechanic to electric and back to mechanic), and installed the motor hub on the front wheel instead? This is the setup for the parallel hybrid (in contrast to the Serial hybrid in the video). I think the motor can be used for regenerative braking and biking uphill. For the regenerative braking part, supercapacitors are more adequate than batteries, because they can charge quickly. Batteries can be added to extend the range of the motor when you don't pedal. In addition, you can start charging the batteries when the downhill ride is long and regen charging exceeds the supercapacitor's capacity.
My aim is to keep the motor disengaged when you don't use it. It engages on regenerative braking or when you decide to use it. My experience with the standard e-bikes is that pedaling without the batteries is difficult even at walking speed. Just to start moving on a flat terrain necessitates standing on the pedal! I can pedal uphill quite well with pedal-powered bikes, but I find e-bikes much harder to ride even on a flat terrain without batteries. Clearly there are some efficiency losses here!
Good idea. This is how the Tesla Semi works. Rear motor optimised for 60mph, front two motors are mechanically disengaged except for acceleration and regen braking (and maybe counter jack knifing).
Efficiency of chain and sprocket is over 99%. Efficiency of inverter is around 95%, and efficiency of electric motors is 91% in best case conditions with average is closer to 70%, both times two for generator and motor separately, for the total loss of useful leg power of 27% at best and 55% average - just for the sake of a gimmick.
There's a very good reason chain drive hasn't been replaced with anything else for so long. The closest competitor is timing belt, and it's ~1% less efficient by itself and you're stuck with hub gearbox which incurs another ~5% efficiency penalty (or no gearbox at all).
Depends if you want peddle assist, or the motor to take over - in which case you will have an electric moped.
The moment there is a battery and an electric motor on a bike, there is no technical reason for it not to be capable of "driving on its own". It is only a legal thing that the motor stops operating when you stop pedaling.
This is true for all e-bikes. So while a motor only driving the bike without added mechanical input from the user (using electrical input instead) may be seem different, it actually really isnt. And because the motor does a large part of the work in the first place on e-cargo-bikes, it also is shockingly unimportant how much input energy the human actually provides.
Bicycle concepts to seat-tubes be like "we don't do that here"
some of these seat ideas are wacky but i do wish people would adopt what kuberg does on their electric motorcycles
I have a better idea: why not put the VR goggles on and rotate a stationary mounted set of pedals. Behold: the ultimate digital bike, the bike of the future!
I really like this idea for city cycling. In some of the major cities it often feels like you are waiting for traffic lights half the time. You just need a three-wheeler bicycle to make it work. Also riding downhill, you could recharge your battery, where now you often just stop pedaling.
Outside the cities some people use recumbent bicycles. Those have very long chains, so the difference in efficiency might be a bit smaller.
I am currently in the Philippines, where in some cities you see a lot of electric tricycles which they call ebikes. Most of them don't even have pedals. As I am used to cycling, and like the workout, I would be more likely to buy one with pedals. Range anxiety is a thing for me, especially since batteries here lose range very quickly.
Some more points I like to note.
1. There is an e-bike named Electrom which is a recumbent design with an electric drive. This bike features a clutch at the pedals and the electric drive, allowing it to switch between a normal electric drive with the electric motor driving the chain and a series electric drive, where you pedal to recharge the battery. Such a clutch allows you to both do regenerative braking, charging using your pedals and using the more efficient traditional bicycle design with chain. Of course, such a design is going to be expensive and heavy.
2. Note that the chain drive electric bicycle design is not the most efficient design. If you want to go for a design that can provide more power, one of the things you can do is move the electromotor to the wheel, to increase efficiency.
3. For a city bike design with regenerative braking, you might want to switch to a design with a capacitor. The downside to a capacitor is the much lower energy density, meaning that you can only use it for accelerating after braking (or maybe something like a 1 km range), but the efficiency is higher, so you would not need to charge your e-bike. Braking provides a lot of power during a short amount of time, something a battery might not be able to handle as well.
This is a very interesting idea... I think I agree with the take that these will start to become more common in e.g. larger more stable cargo bikes as battery charging could be done at optimal leg speeds even when stopped. For things with two wheels though I don't see this being all that appealing, since you are relying more on regen and downhill movement to recharge the battery. For example I know I would always rather have something direct drive when starting from a stop for stability reasons, since this is one of the main reasons I prefer commuting on a bike and not e.g. my moped. The weight and CG will also matter quite a bit in that scenario... but many of the bikes shown here had top mounted batteries. Seems like the current products out there are a little miss-aimed for the market of traditional cyclists... maybe we see this becoming more popular with new riders but I think this will be a hard sell for traditional drivetrain owners (even on ebikes).
that is a very bas idea. 50% efficiency there is no point at all that this thing exist.
take a chain or electric motor, but this thing between the 2.
Very interesting. With regards motor control, there’s a company called EXRO that has patented and in production modules to take care of this. I think if they brought it down to 48V it would solve a lot of these issues.
But efficiency. wayyyy to poor.
Very nice overview, however I do feel you loose a lot of control over your bike. As a cyclist, the ability to determine how much power you provide on your pedals is pretty important. Thinking about steeps hills and such. I would image it feels pretty weird to have a difference in peddling speed and the bicycle speed. Would love to try it out though!
I see no correlation between bike speed and rate of sale.
Maybe we need a dual mode drive - when you pedal forward, you drive a fixed gear belt (at your typical cruising speed). When you pedal backward, you power a digital drive.
The belt drives the rear wheel, while the digital drive generator/motor drives the front wheel.
This dual mode system is still very simple, but you don't sacrifice efficiency at your typical cruising speed.
it's not digital. it's not powered by ones and zeroes
@Armament Armed Arm Carbohydrate-electric (diesel/electric are both the energy carrier, no?)
A decent thing for the next gen of cargo/delivery bikes doing last mile stuff.
For propelling a solitary human and their backpack over any distance that's a massively inefficient lump of complex solution to solve a challenge already comprehensively solved a century ago, and recently tweaked with e-assist.
The argument about chain and derailleur is no longer valid with belt drive and modern hub gearing.
It misses the point of why the bicycle (and e-assist) is so efficient - they take the force of our strongest muscles (quads and glutes), and using leverage and gearing transmit and multiply that energy into forward motion.
This doesn't do any of that.
Agreed, this definitely veers into the territory of "just get an e-motorcycle/scooter at that point" territory
You mostly just convinced me that regular e-bikes should also feature regenerative braking
Regenerative braking on an ebike isn’t all that it’s cracked up to be. I’ve wrenched and sold bikes with that feature - I wasn’t impressed. With a car weight to drag ratio is much more favorable compared to a bicycle so you don’t get much extra benefit. With ebikes that offer regen braking or while coasting - if you run out of battery it’s worse than pedaling a bike with a flat tire and heavy whereas a regular ebike is just heavy. Regenerative braking systems favor hub motors vs mid drive as well. As someone with 20+ years of bike industry experience - I wouldn’t buy an ebike with regenerative braking. If you want bicycle efficiency aerodynamics are where it’s at. At 14mph/22.6kph 70% of your energy goes to air friction and it gets exponentially worse as speeds increase. The real improvements in efficiency are aerodynamics.
@@stefhirsch6922 you're right for flat riding, but it's a completely different story in the mountains. On a steep mountain descent, you lose a large amount of energy with little advantage - a bit of a thrill, but not actually much time saved relatively speaking, if the next climb is a
@@leftaroundabout ebikes with regen braking that are used without power assistance are worse than riding a bike with a flat tire. They just aren’t good and don’t work. So lots of extra drag, significantly reduced efficiency and greater weight are not your friend when climbing steep hills. Extra fitness, easier gearing and standard electric power assist (or gas) are all strategies which work. A system with at best a 58% efficiency compared to 98% displays a clear winner. That translates to a 42% loss vs a 2% loss. A system which is 21x less efficient, significantly heavier and more expensive doesn’t seem like a performance upgrade to me. Until generators and batteries/charging systems are significantly more efficient regenerative braking is a crap idea. The juice isn’t worth the squeeze. Bicycles haven’t changed much in the past 130+ years for a reason (unless we are talking about aerodynamic fairings or recumbent bikes). They work. Lever driven propulsion vs a crankset which rotates the pedals in a circular motion to transfer the power through a chain or drive belt to the rear wheel are the most reliable, durable and efficient that have ever been attempted. Diamond frame configurations rule bike designs now as they did for over a century - they are the strongest, best handling, lightest… that have been tried. The bicycle is the most efficient method of transportation due to its intelligent elegant design. Replacing an incredibly efficient, lightweight and durable design for a Rube Goldberg abomination isn’t progress. Seriously when adding bearing drag from the rear hub, pedals and bottom bracket to the frictional losses to a chain drivetrain would still be 96-97% efficient. A car will have over double that amount.
@@stefhirsch6922 perhaps _some_ e-bikes have more drag than a flat tyre... but that's because they're bad e-bikes, not because they have regen braking. Many especially of the cheaper models seem to be based on industrial motor designs, where price and longevity have priority before efficiency and weight - the exact opposite of what you get with performance bike components.
Electric motors, even powerful ones, can run with very little friction. A bigger problem is the torque required, which generally necessitates a gearbox, and again these are often way less efficient as they could be. In principle this could be replaced by an encased belt- or chain reduction, and then you would get the same efficiency advantages of mechanical drive trains.
Or even just a better dimensioned / better tolerance / better lubricated gearbox. FWIW, even my cheap e-scooter has regen braking and still coast decently with the electrics shut off.
The actual problem is that it's cheaper for the manufacturers to put a freewheel after the gearbox and compensate for losses of the electric drive with a bigger battery, than to optimise the system to be good at regen braking, and most e-bike buyers evidently don't care either, since they anyway charge the bike from the wall plug after every ride.
I quite agree that mechanical bikes are great and I won't buy an e-bike any time soon - but they do have two things that keep annoying me: *1.* derailleur drivetrains are a maintenance nightmare, especially in cold, wet climates, especially if (like me) you like to ride in mud or on salted winter roads *2.* mechanical brakes are a bit sad, not only wasting all that energy you've preciously laboured on the way up, but also wearing out in the process. (And, they too are a bit temperamental, with dirt/oil contamination ruining the response.)
So _if_ I were to buy an e-bike, it would have to have properly working regen braking too.
@@leftaroundabout most of the maintenance issues with externals drivetrains and derailleurs are A. contamination and B. lack of lubrication. Try fully degreasing your chain (yes it requires removing it from your bike and either putting it into a plastic tub with degreaser and shaking vigorously for a minute or an ultrasonic cleaner with degreaser, rinsing blowing it clean with a compressor nozzle and relubricating with a better lubricant. Ive had good luck with “dumonde tech lite” lube - follow the instructions exactly. For shift wire housing middle burn cable oilers are a great option. For rim brakes in the wet I recommend koolstop brake pads (black for dry, dual compound for mixed conditions and salmon/orange for wet). For disc brakes semi metallic are going to last longer. Try out galfer brand, swissstop, or koolstop. Most brake pads are typically “organic” or resin which are quieter but don’t last as long or stop as well. *Good* mechanical or even rim brakes which are set up properly stop just fine. I’m a fan of shimano bike parts but their brake pads for rim brakes kinda suck. If I bought a new bike with shimano rim brakes I would immediately take them off and throw them in the trash. They wear out rims and don’t stop well while wearing out quick.
I think the two main problems are efficiency (obviously you addressed this), and everyone's familiarization with chain bikes. If they change the concept to having you control the motor with a hand throttle like a motorcycle, I think it would help because then people could auto-pilot pedaling and focus speed control to their hand, an entirely different limb, eliminating the coordination issues and eliminating the need for fake gears since speed would be controlled independently of pedal speed
Bicycle drive trains using chains or belts are 95%+ efficient. This means, our high torque but limited power legs do not need to work hard to propel the bicycle forward. Any gear mechanism or electrical generator/motor system added to the system between our legs and the pedals connected to the wheels, reduces the efficiency well below the 95%+ efficiency of the chain or belt direct drive. This means, it feels harder when pedaling to go the same speed. Digital drive doesn't sit right with me. Let me know what you think.
The main application may be heavy cargo E bikes, where most of the used power don't come from the rider anyways. It eliminates the need of having a direct chain connection, which gives more design freedom and eliminates the need of having a differential on a cargo bike with 2 rear wheels.
On a normal bike the only advantage is less maintenance, which is "paid" with less efficiency.
I think the Twike (a hybrid between a small car and a bike) used such a system long ago
What I think is you didn't watch the whole video.
@@Pastamistic I watched the whole video and they are right. So what do you mean? This system is super inefficient for sending power to the wheel.
I can't see it ever hitting efficiency needed to replace a conventional drive (whether chain, belt, or crankshaft) on a bike without an additional power source, but on electrically assisted bikes it can start to make sense, particularly on cargo bikes where not having a chain may enable interesting geometries or allow more cargo space. Even if most of the power is coming from the battery, I feel there's something about pedaling to control your speed that gives you a connection to the road that cars and motorbikes (and bicycles with throttles) lack.
I freak out every time you call it "digital" drive. Electric drive would be better fitting because the concept sticks out for using electrons instead of chain to transfer energy. The controller is just there to increase efficiency.
About efficiency: 80% is pretty low for a motor, there are standards for motor efficiency that go up to 97% and beyond. I don't know how well that number can be maintained with variable rpm thougt. Also, 10% transfer losses are a bit conservative and could be improved upon. One solution we might see is two motors front and back: One more for torque, one for speed, both for 4wd-equivalent better tracktion and reduced wear on tyres. Brake usage and wear is also greatly reduced, I guess it should be ok to shave the rear brake of and just have a (smaller, lighter) front brake. With optimisations to the frame the weight penalty will likely be reduced further.
The motor driving the wheel could be up to 90% efficient. Most of the loss will be on the generation side. That motor is going to have a lot of loss from the variability of the rpm. Efficiency in generators drops off exponentially the further away you are from its peak power output. Then once you add on the transmission losses that 60% is bang on what you would expect. Obviously you could improve that slightly, but don't expect anything more than a few percent.
Do you want to work twice as much on a bike, than this electric (not digital) drivetrain seems perfect for you!
The efficiency of an electric motor is about 80%. The efficiency of the generator is about 60%. Thus only 48% of the energy can be used to accelerate. In comparison the mechanical efficiency of a bike is about 99%.
Bafang have recently released a 3-speed hub motor with automatic shifting, which might be a good fit for a digital bicycle. As long as bicycles don't exceed 30 km/h in the city, and are compact, quiet, and safe for people around them, I don't really care how they're powered. But I also like the idea of compulsory workout a bit. Nice video!
People will always find ways to make them go faster.
Like, when the Bosch smart system came out, it didn't even take a week to find speedboxes for it.
Fair point, though, they should be locked when they're delivered, and will be for sure. Countries wouldn't give the green light otherwise
Terrific content Alee! Thank you. Good stuff. Seems interesting but the chain will not be dethroned!
Based on your informative video, I fully expect that the digital ebikes will be in production, and will have a really important place in our cycling world. I feel that it will be a long time however due to cost and development, before there is a significant advancement in expansion market share for the digital ebikes, but give all of obstacles, there is enough positives to succeed, and I would greatly consider owning one, as long as cost and weight are controlled so that the senior population can afford, and handle the weight of such a bike. The cost and weight are now and important for myself and my wife in those areas. Based this video, I feel that the greatest benefit may be the physical therapy aspects, as well regenerative health care as a side benefit from an enjoyable exercise experience. AWESOME VIDEO!!!! Keep them coming!
The real reason why you won't see it in production anytime soon is bike laws. These bikes would simply have to be too slow to be legal without a moped license. A shame because these bikes would offer a smoother ride than any other bike.
I think I’ll stick with my analog bikes. But you do you.
you could also do a front wheel drive which would hugely improve stability in a muddy/snowy terrain.
That is absolutely not what happens with a two wheeled bike. Losing the front will guarantee falling
@@colin1780 losing the front is a guaranteed fall with rear drive. with front - not so much, you just push on the gas and regain control.
have you tried riding any front wheel driven two-wheeler?
@@swancrunch i work in a bike shop and front wheel motor driven bikes are known to be less stable. Going on ice or losing grip will mean that all your weight will fall to the front. Rear will most likely just make you drift a little
If you could dial a pedal load in like a turbo trainer I think it could be very good. You could set the pedal load at say 150w and then use the battery to drive the bike.
I think, that's exactly what this thing do.
NOnetheless, it adds complexity compared to a normal chaingear (or belt gear), and reduce hugely efficiency. It's useless.
what could be the efficiency of a well designed hydraulic drive ?
with dual pistons driven by the pedal crank and similar arrangement at the wheel, perhaps with 4 pistons instead of 2.
and gearing could be infinitely variable by mechanically automatically varying the conrod length.
a small lever could vary the amount of effort you want to put into peddling and your speed would be automatically adjusted accordingly.
as hydraulic drive ticks the boxes of lightweight, reliable, self lubricating , fully enclosed, and cheap to produce.
Hydraulic drive efficiency are generally also around 50/60%, and that's with turbines. Should be checked for such a small device, but counting this could have been used anytime in the past 200 years and is not a currently known popular method, I guess the results are not very good.
Yay! Recumbent bikes without a long, heavy, dirty chain would be great.
Also, correct me if I'm wrong, the first chain drive bikes were less efficient than the latest models.
Hundreds of years and thousands of little improvements here and there and we've got some really amazing chain drive options.
The more people use electric drive over hundreds of years and thousands of little improvements, it could be amazing.
Keep up the good work.
I don't think I have hundreds of years to wait for all of that to go down. It's probably a lost cause tbh. I can't imagine anything close to one to one transmission happening without some kind of clarketech being involved.
Gotta admit it's a clean looking setup. I could see motorcycle guys eating this up if the efficiency was better.
mechanical drivetrains are far better than any kind of electrical drivetrain. why are we making these costly drivetrains when we have something that already works better anyway?
What's digital about it? Electric, yes. Electronic, maybe. Digital? Nope.
Agree, it’s a real misnomer! Content is great, though.
Why not just get one of those electric scooters so you don't even need to pedal