Hey Hambini! My wife & I ride a tandem bike (I also ride singles). I've found the effects of wind to be much greater (ie. amplified) riding the tandem vs. riding in the same conditions on a single bike. So headwinds etc. on the tandem cause us to go much slower despite working much harder; and tailwinds generally help push us along faster than the same tailwind would on a single bike. I guess this has a lot to do with surface area etc. It would be really cool to be able to get some sort of scientific analysis of a tandem team - where most of the drag occurs, and where/ways we could improve our aerodynamic efficiency. Cheers man 👍
That vector analysis blew my mind somewhat. If I had actually thought about it it would have made sense to me being from a physics background. The lack of compensation for forward speed versus wind tunnel speed will make a huge difference to the numbers when you factor in the v squared relationship. Without crunching numbers I would hazard a guess to say the numbers regularly presented are often out by 30-50%. This is a massive margin of error. For very low yaw angles it's fine as then you are virtually in wind tunnel like conditions but when you are out on the road I reckon the 30 degree yaw angle wouldn't be very uncommon.
I just think it's all totally fascinating and to share your knowledge in the style of a 5 year old means I learn something from each and every video you make. Good on ya Hambini. I know this reply won't generate any algorithms unlike others but that's a big thumbs up from me pal.
I can ride this position with a herniated lumbar disc. So it aint bad. Had a TT today. Went faster by almost a minute on a 35 min course. Kept my head down and hardly ever looked up. Power was also higher. Am highly de-trained vs last year so training is also bullshit. Just sleep and eat 😛😛 and copious amounts of lockdown Rioja. And no disc wheel. I hate cornering on it in the wet.
Must be nice to only have one herniated disc. C3 - C7 and L3 - S1. Ah the joys of visiting the neurologist to discuss why your powermeter crank and pedals have such odd data!
Oh yes great, Mr Peak Torque, brilliant! Can't wait for the reaction video! Saw his bb video, he replied to say cost was the main factor. Shame you couldn't arrange a joint critique with MAB on aerodynamic theory on TT positions. As a technical cycling journalist no doubt her input would have been invaluable...
So Hambini, you and everyone else knows that I am a fanboy, but 44 seconds in and I must say that I do like the new format, but expect that there will also be "normal service" in future!!!! Love the new material.
With enough extra hold hair spray (approx 20 litres), you can permanently fix your barnet into an aero helmet form. It'll get a bit loose as your bouffant grows out underneath the glue, but think of it as complimentary cushioning. In wind tunnel tests, your ear shape will be a major factor, so staple them to your noggin properly. It'll only hurt when you breathe. Minimal gains ftw. Sincerely, Von Fronkunshteen (Baron)
I use the TT position with my regular dropdown bars when I am doing my downhills. It does make a difference in that position so there would be less drag. But I do use the regular sitting position to create drag with my brake calipers in order to stop the bike. It really works.
You're ace. Intelligent, self-deprecating and entertaining. Can't believe I've wasted my time watching those knob grommets at Gormless Cycling Newbies ......
When you show a side view and pontificate on separation, your comments are valid for the central one inch slice of the object. (that may be generous) If you take a slice of the object just a little off center the whole thing changes. My shoulders are 23 inches wide, what about the other 96% of me? Tuft testing would be cool.
So I had an interesting one, and something that to me always seemed off when I was told it. In the bike shop I worked in we had the cervelo rep come in teaching us about their new bikes and he claimed that using disc brakes allowed them to design a more aero dynamic fork and frame because the air around the wheel was already disturbed and would cause the disc brake caliper's effect on drag to be minimal, and the gain from the improved front of the fork was more beneficial. Now to me this always seemed off, but I kinda trusted it as my belief was they knew more than me and had more resources to test it. But seeing these videos has made me think possibly I'm not quite so stupid and that rim brakes would be more aerodynamic. It would be interesting to know your thought on it.
Why do I have the sneaking suspicion that we palookas will do 30-35 km/h with no forethought and going 40-50 km/h is for 'grownups', not us mere mortal weaklings. The point is- it's the motor, stupid! Pros do amazing average speeds and amazing top speeds because they have bicycle for breakfast, bicycle for lunch, bicycle for supper- 365 days of the year. 3 hours, twice daily- rain, sleet or snow. Fancy equations are good and great. POWER, gained through years and years of excruciating daily, weekly, monthly, yearly work, for years on end: where cycling greatness lies.
@hambini Curious to understand why the Giro Aerohead ultimate is "faster" without vents when the regular Aerohead with vents could continue the attachment as described on the back like the Met helmet.
Hambini, my favor quote from my first boss after graduation (I'm an MechE with a masters) was "you can't train arrows.". Despite my thermodynamics background, he was critiquing somewhat nonsense representation of air flow. In essence he was saying "You can make all the PPTs with arrows on them to represent air movement that you want, but those arrows don't necessarily represent what happens in real physics." I quickly learned due to my background. I'm unsure if you're other experts have the background to learn. For example, one of my children has a physiology and exercise science degree. When I talk aerodynamics with her, she's lost. I won't generalize that all of the physiologist that direct wind tunnel tests are clueless, but when I see some wind tunnel aero tests, I tend to see lots of trained arrows.
@David McMillan Bachelors today are about as useful and qualifying as a high school diploma. You can tell who is fake or not based on the type of experience they've obtained afterward. That's why FLO cycling is a huge red flag. Two guys with bachelor degrees with no practical experience claiming to be aerodynamic experts.
Obree knows alot about cycling. He'd be punching holes in this blokes theories left right and centre Bottom brackets with less friction? What a load of rubbish
Out of the popular manufacturers of triathlon bikes which one would you think has a better more "aerodynamically correct"/better bike..ie Scott Plasma (old/new rim/disc), Canyon Speedmax (old and new rim and disc), Specialized (rim and disc), Q-Roo, etc etc..
I see a lot of people referring to the drag equation what talking about when to get out of an aero position and move into a more powerful but less aero position (about 20km/h) am I correct in thinking that the 20km/h people refer to is net velocity rather than rider velocity so for example if you are riding into a 30km/h head wind you would always be better off staying aero and if you have a 30km/h tail wind you should almost always stay in a more powerful position (unless you are going over 50km/h)
I love this video. I race TT’s, and can hold > 30mph for 10 miles so aero does have some effect at that speed. However, I went to a tunnel for the experience and to see the data. After I was there for about an hour testing positions, and “gaining watts” per the instructors, I asked how this equates to real world situations because the bike was in fact locked into a straight up and down position. They said that the rocking back and forth absolutely matters and people trying to find every last drop of aero gains are wasting time and money, and we had a laugh about my being there as well. You do have gains from being smaller on the bike (not necessarily LOWER, mind you), however, there’s a tradeoff to power output. I’ve reached a point where I have a “comfortable” enough position on the TT bike, and if I can do something to get more power out of my body, I’ll take that over alleged aero gains. Train more, core, flexibility, things that let you stay in your position LONGER, and without stress, will produce more gains. The worst thing I’ve done to do my own aero testing was throw my TT disc rear wheel and 80mm on the front of my road bike, and do a known 50 mile route, varying terrain, and my time/wattage/perceived effort was the same as my 1350 gram training wheels, within a few watts type of thing, not enough to matter. Could be bearings, could be perfect tiny amount of wind that skewed the data, but I can honestly say it made zero difference to me. Body position is key.
@@Sills71 yupp, exactly. The width of a frame is what, 3 inches? Barely measurable. Take someone on the p5x that has their head popped up high vs someone on a steel road frame, no aero, but is fitted and lower, and yeah, there goes thousands of dollars down a toilet.
@@Sills71 There is probably an effect on pedaling stiffness depending on how frame tubes are shaped. But considering how little of the frame is actually exposed to headwind there is little argument to be made in how much you can improve frame aerodynamics for more forward speed. Crosswind could be a consideration but most road bikes seem to be optimized to catch as much crosswind as possible, the opposite of what you'd want...
Potentially stupid unrelated question here... i would assume that wheel manufacturers design wheelsets to work together (front with back). When I ride with 2 mavic 60mms I seem to go fast, but when I have just the rear 60mm in I seem to be really sluggish. Is there a possibility that the non aero front wheel throws off the aerodynamics of the aero rear? Or is it a coincidence and it is purely placebo effect?
Well, the front wheel will likely matter a lot more. Since it's encountering clean-ish air, and often other things have disturbed the air by the time it gets to the back (once it's spoiled, spoiling it some more doesn't have as large of an effect. If it was practical, the front wheel would actually benefit a lot more from a disc than the rear. The problem is that any kind of wind tries to throw the steering all over the place.
Hambini if you take a look at the position of Peak Torque, who is resting his arms on this thing that sits atop his steer, and you think that he is driving fast in that position, whilst the levers of his breaks are waaayyy down and to the sides, don't that give you some thoughts?
Thanks for creating the illustrations & explanatory information & going through it all in a perfectly ordered way. I'm not a time trailer but I do like watching time trials when they happen to be on tv like during the Tour. Be safe. 👍☮️🌞🦠😷🚲
Not so sure about the helmet. I think the reason you see the shorter ones like the kask ones sky were using is because people generally don't look straight ahead all the time. Once you look down with that massive tail on the back it's miles worse.
Excellent point about the drag vs. yaw graphs not increasing the air velocity as yaw angle increases. (What's the point in modeling a stationary bike?)
Regarding basebar - aero bar separation. There's some data out there (CFD and wind tunnel, fwiw) that says that a gap of 40mm or more is more aero. So either have a big gap or slam the aero bars right down to the basebar. Also, some riders put the aero bars right at optimum position and have the base bars as low as they can go for handling around corners and technical descending - equivalent position to the drops on road bike. Not fond of that extended lever and extra shear force on longer bolts, and my TTs aren't technical. So haven't tried it myself.
if it's for civil aerospace, the aircraft is flying so fast that the effect of "wind" is negligible and ignored. If it's in military aircraft that are performing unsteady flight then it's a different kettle of fish and not one where I can comment..
Happy to see that my bikefitter - who is the biomechanical expert and not an aero expert - has fitted me right. A slight rise at the end of the aerobars to relieve pressure from my shoulders (which strangely resulted in more power) but no praying mantis (arms horizontal). He also minimized the spacers under the pads, he said 'you don't need it and many TT-rides add them because it looks cool' 🤪. Furthermore shorter cranks so my saddle could go up to get my back horizontal. I did switch from the Giro Selector (long tail) to the Aerohead (short tail) because I couldn't keep a position in which the selector would stay between my shoulders, most of the times it would end up a few centimeters higher. Curious if it's really a problem?
following Hambini's channel I have learned so much !! ..all the bike tech stuff that my bike dealers never told me ..all the english vocabulary that my english teachers never told me 👍
I have several bikes set up the same, when I change bikes after I have ridden one for awhile, it takes me about a week to get used to it. I have ridden them for years but find this always happens.
Love you aerodynamics video. Would love to see a no rules aero bike design by you. On the topic, couldn't we do "shapes"at skinsuit like motogp, because all chest airflow could maybe help at avoiding detachment at the back? And couldn't skinsuit be attached to helmet by imans or zip?
Is a low center of gravity actually more stable on a single-track vehicle? I've been experimenting with recumbent bikes, and generally the lower, and further forward you are, the more trail you need to make the bike feel stable. Bikes with a seat that's higher and further back are much less twitchy and hard to balance.
Hi Hambini. As a fellow aerodynamicist, I have to say that I love your attitude! Your analysis (through many of your videos) is mostly sound. I only say mostly sound, because I am also unconventional in many respects and have some differences of opinion to the mainstream aerodynamic opinion. That doesn't necessarily mean that I am right and I can say that I have learned a few things from your videos. I am in the strange position of having migrated from very high speed aerodynamics to working with quite low speeds. (ie < 70 knots). I also do a lot of cycling so your analysis interests me greatly. Keep up the good work.
Jean Paul Ballard has stated he sees marginal benefit in a disc wheel over his Swiss Side Hadron Ultimate 800 rear wheel at 45 km/h yaw-weighted at 45km/hr. Think he said up to 2 watts (and only 1 watt at 35 km/hr). Sounded like you thought there might be more? Why is a disc more beneficial for tall riders - stability related?! Funny how Rossi uses Giro older TT helmet and Peak Torque uses their new and improved supposedly faster by c.5w at 45 km/hr!! I know helmets are rider-specific though ;) Would love to see more of these videos - good work as always!!
Any chance you can remove spokes from the equation to avoid turblence, I think the better. If we could safely ride two disc wheels front and back, that would be the best. But a front disc wheel is highly unstable. On the track you do see double-disc wheels fairly often.
@@mikew466 Yes, I don't think there's much doubt at all that the discs are aerodynamically better than spoked wheels - I think the difference is between those who see 1 -2 km/hr difference between deep section spoked wheels and discs, and those who see considerably more
You can give some rules of thumb based on intuition or general physical principles, make predictions with CFD (if looking for deltas on the order of 5--10% or greater), but at the end of the day, fluid dynamics is nonlinear so the only way to know for sure is to test. And yes, a wind tunnel measurement is just a more accurate (and expensive) way of predicting what will happen in the real world, but it is not that. Just because some shape looks sleeker, or seems like it has fewer features to induce early separation, doesn't necessarily mean it will be lower drag.
For TT wannabes like me.... ski extensions? S-Bend extensions? Straight? I can't really do straight (horizontal) extensions well because of numerous wrist injuries, but curious on what is preferable.
What WE really WANT is MORE SPEED. Shit that ACTUALLY WORKS. Most ppl fail 2 realize U R the MAIN source of DRAG and POWER. 4,000€ bike with a rider that makes 200 watts is NOT faster than a 1,000€ bike and 300watts.
this is fascinating but is it true? How come if the low hands position is more aero have we seen almost all riders move to a position with high hands or atleast much higher than flat/parallel hands to elbows?? Also why is the side on view looked at most with riders? surely the wind see's you from the front, and there we can see that getting as narrow as possible would be more aero aswell as having high hands to minimize the space between hands and helmet, so the air can maybe attach effectively and not hit into your stomach which would act as a parachute? thanks hambini please let me know, i just want to get faster!
Another area that cycling aerodynamics have been pushing the past few years is a lower base bar, and a and higher aerobar with tall spacers. Like the Peak Torque guy's handlebars. Supposedly the air is cleaner because it can flow between the gap in the aerobars and the basebar. Whereas with the older setup of the basebar and aerobar together, there is a larger frontal area in that setup and the air is more turbulent. Is all of this really better? Who knows, but I've noticed pros follow trends, so if everyone starts using a certain position or bike setup, everyone copies each other.
Nah. I've found the same thing, sometimes. It might just be that the old saddle is bad, so removing the badness is "good" even if a lot of saddles would seem just as good. I think probably more than a change in saddle, would be something like a change in saddle or bar position, which will feel "wrong" for some time, even if it's ultimately fine long-term.
Hi Hambini. Are you able to do a video where you explain why a lenticular disc wheel is faster than a flat rear disc wheel? Also, do aero overshoes make any difference or are they just a waste of money?
Peak Torque has a lot of similarities to Wout Van Aerts and also Rohan Dennis, size, position, bike and helmet too actually... Two of the fastes people on bikes in the world atm, Wout won the Belgian TT championship, and the iTT in the Dauphine, before he crashed in the tour. Campenaerts and Evenepoel are also fast of course, but they both have a different build and position (much smaller) I wonder if they can really improve much, or if they basically have it right (because they are already winning the TT that they aim to win) They have a pretty high interest in getting it right and don't just listen to the cycling media, they work together with universities etc and do legit testing.
Hey Hambini, you mentioned that you can optimise your equipment for better aerodynamics. No 2 was the handlebars - what would you recommend? I may have missed it in your previous videos or posts about handlebars. Cheers. Chris
Hambini could you please analyse velomobile aerodynamic comparing alpha 7, after 7, milan Sl and snoek ? That are normally the top of the line on aero for velomobile. The velomobile community will be please to have out of the box thinking... Thanks for your video.
with respect to your recommendation that wheels be fitted close to the frame to prevent voids/turbulence, how do you think the ventum tri bike performs aerodynamically? (yes it looks like monkeyspunk).
Would there be a difference in drag between having vents in front of the helmet or not when the head is in a low and good position such as what Rossi has? For example, does it give Bell Javelin that have vents in front of the helmet more drag than it would without those vents?
Hey Hambini.. Another great video! Wanted to ask a question about changing aero wheels. I'm currently using Lightbicycle R45, they are 45mm deep, 25 external, 18 internal. I'm thinking about Lightbicycle AR56, so 56mm deep, 30 external. Model/make doesn't matter but I wanted to ask your thoughts on how much extra 11mm in depth and slightly wider would help?
About flow separation. Does the trailing edge of a wheel significantly contribute to drag. And if so would using and symmetric ovaloid shape on a rim tire combo help with that?
Compared to what the air's had to do before getting off the back tyre to let the rider's body through, I can't see the trailing edge of the back wheel making any usable difference. Also the shape of the tyre has to follow a completely separate set of constraints, namely that it needs to grip the ground and that it's a thin walled pressure vessel holding back a constant pressure on its inner surface, so it will always choose its shape in response to that load. Adding reinforcement to the tyre to change its shape is a possibility - specifically filling in any dig between the rim and the sidewall might be an option (Some wheelsets are doing this to some degree already I think), but the trailing edge of the tyre is the tyre tread, so unless you can make changes without impacting grip and comfort on rough surfaces, it's a big ask that I'd be amazed to see produce a useful payback.
Nicely explained. I do have a question though. I use a Kask Bambino TT helmet with a visor. I do own a Specialized full aero helmet too and use a nopinz skin suit with the number concealed. For real world conditions, in your opinion as a well respected five year old, which do you think is best helmet wise? I wear Oakley Radars with the Specialized lid by the way. Thanks, Steve.
I've pressed spacebar to pause the video so I could get myself a bowl of some delicious rice and a popup message appeared: "Added to Liked videos". Damn those computers are so smart these days.
Excellent thank you. Great Hambini, is the frame (carbon frame) on a 2015 R2 Cervelo any good, how about the BB as I am having a new old stock bike put together for me so test drive. The price is Thanks !Chris from Canada.
More aero advice for useless laymen like me, please :) I'm still trying to determine if horizontal arms allow me as good power generation as raised (mantis) setup. Maybe just a case of getting used to it?
Have you seen the 'wind tunnel' app on the apple App Store. Show airstreams and the turbulence caused as the wind goes around it. very basic but good way to illustrate airflow behaviour.
Don't forget that the rider is moving forward at a reasonable speed, so the overall vector of the flow will be from a generally fore/aft direction. Unless it's really blowing a hooley in which case you're in for a bumpy ride anyway :-)
With your arms in the low TT position should you try to have them together or slightly apart creating a slot affect and so reducing the low pressure behind your upper arms?
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
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Accidentally cast to my neighbours TV. heard the introduction through the wall. I have some apologising to do.
Nearly Spat my tea out🤣🤣🤣🤣
If they didn't collectively keel over due to a heart attack.
If I was your neighbour, we would be sharing beers right now.
Why are you on their wifi?
@@jakewhatling4 their router broke so I let them use mine. However since they all died from a heart attack that wont ne a problem anymore.
After 33 years of riding and studying how aerodynamics work, I have concluded that I ride faster with a tailwind.
That is just GCN BS, don't believe a word of it!
I ride so fast, there is never a tailwind.
I ride even faster with a motor on, and finally concluded that aerodynamics is booolshit.
lol... there is just wind and good days... :)
kids today...sheesh!
For me, the real race is getting to the volume control.
Thanks, as ever.
Hey Hambini! My wife & I ride a tandem bike (I also ride singles). I've found the effects of wind to be much greater (ie. amplified) riding the tandem vs. riding in the same conditions on a single bike. So headwinds etc. on the tandem cause us to go much slower despite working much harder; and tailwinds generally help push us along faster than the same tailwind would on a single bike. I guess this has a lot to do with surface area etc. It would be really cool to be able to get some sort of scientific analysis of a tandem team - where most of the drag occurs, and where/ways we could improve our aerodynamic efficiency. Cheers man 👍
The intro gives me more life than eating after a bonk.
@@abedfo88 well eating after bonking is better than sex so
@@polarnightaudio Better to down some table sugar. Then no bonk.
@@82vitt you think people bonk on purpose?
@@Bayo106 Well, the commenter above suggests they might do :).
Hambini “maybe a bit too far.”
Well there we have it, hell has frozen over.
That vector analysis blew my mind somewhat. If I had actually thought about it it would have made sense to me being from a physics background. The lack of compensation for forward speed versus wind tunnel speed will make a huge difference to the numbers when you factor in the v squared relationship. Without crunching numbers I would hazard a guess to say the numbers regularly presented are often out by 30-50%. This is a massive margin of error. For very low yaw angles it's fine as then you are virtually in wind tunnel like conditions but when you are out on the road I reckon the 30 degree yaw angle wouldn't be very uncommon.
Hambini makes engineering entertaining.
I just think it's all totally fascinating and to share your knowledge in the style of a 5 year old means I learn something from each and every video you make. Good on ya Hambini. I know this reply won't generate any algorithms unlike others but that's a big thumbs up from me pal.
I can ride this position with a herniated lumbar disc. So it aint bad. Had a TT today. Went faster by almost a minute on a 35 min course. Kept my head down and hardly ever looked up. Power was also higher. Am highly de-trained vs last year so training is also bullshit. Just sleep and eat 😛😛 and copious amounts of lockdown Rioja. And no disc wheel. I hate cornering on it in the wet.
Must be nice to only have one herniated disc. C3 - C7 and L3 - S1. Ah the joys of visiting the neurologist to discuss why your powermeter crank and pedals have such odd data!
@@lobuxracer are all those alphanumeric terms Cervelo bike models?
No wonder they're busted.
@@FLMKane 😂🤣😂🤣😂 Sadly, like Hambini, I have an S5, but it has a Hambini BB, so half the battle is won right there.
Must have broken my neck in mtn bike crash 3 months ago. No pain, no disability, just walked out and don't want to know. 60 years old.
Oh yes great, Mr Peak Torque, brilliant! Can't wait for the reaction video! Saw his bb video, he replied to say cost was the main factor. Shame you couldn't arrange a joint critique with MAB on aerodynamic theory on TT positions. As a technical cycling journalist no doubt her input would have been invaluable...
yeah...stress on the ‘input’???😋🤨🤩
Outstanding videos ! Extremely informative, superb communication skills and brilliantly entertaining.
I readjusted my position/posture after watching this vid. Positive results. Thanks.
Well explained, sir. Great watch and very educational. Kudos to you and Peak Torque for cutting through the BS!
So Hambini, you and everyone else knows that I am a fanboy, but 44 seconds in and I must say that I do like the new format, but expect that there will also be "normal service" in future!!!! Love the new material.
I want a pair of Hambini cycling socks!
Yeah, the really tall ones with vertical ridges will reduce drag. He never did make the sock video.
As long as there NOT UCI legal
I'd rock Hambini gear. Choice slogans on the socks. "Aero" stickers. Etc
Need to have mock UCI measuring calipers as part of the logo, 10% oversized and tested away from nearest wind tunnel!
I agree. Cycling socks would be perfect and I'd buy a weeks worth. Tall cuffs for sure.
With enough extra hold hair spray (approx 20 litres), you can permanently fix your barnet into an aero helmet form. It'll get a bit loose as your bouffant grows out underneath the glue, but think of it as complimentary cushioning. In wind tunnel tests, your ear shape will be a major factor, so staple them to your noggin properly. It'll only hurt when you breathe. Minimal gains ftw.
Sincerely,
Von Fronkunshteen (Baron)
dude I was laughing my ass off, thanks I needed that
I use the TT position with my regular dropdown bars when I am doing my downhills. It does make a difference in that position so there would be less drag. But I do use the regular sitting position to create drag with my brake calipers in order to stop the bike. It really works.
5 year old with a big brain
simple sound 🧠🚲
You're ace. Intelligent, self-deprecating and entertaining. Can't believe I've wasted my time watching those knob grommets at Gormless Cycling Newbies ......
When you show a side view and pontificate on separation, your comments are valid for the central one inch slice of the object. (that may be generous) If you take a slice of the object just a little off center the whole thing changes. My shoulders are 23 inches wide, what about the other 96% of me? Tuft testing would be cool.
So I had an interesting one, and something that to me always seemed off when I was told it. In the bike shop I worked in we had the cervelo rep come in teaching us about their new bikes and he claimed that using disc brakes allowed them to design a more aero dynamic fork and frame because the air around the wheel was already disturbed and would cause the disc brake caliper's effect on drag to be minimal, and the gain from the improved front of the fork was more beneficial. Now to me this always seemed off, but I kinda trusted it as my belief was they knew more than me and had more resources to test it. But seeing these videos has made me think possibly I'm not quite so stupid and that rim brakes would be more aerodynamic. It would be interesting to know your thought on it.
Why do I have the sneaking suspicion that we palookas will do 30-35 km/h with no forethought and going 40-50 km/h is for 'grownups', not us mere mortal weaklings. The point is- it's the motor, stupid! Pros do amazing average speeds and amazing top speeds because they have bicycle for breakfast, bicycle for lunch, bicycle for supper- 365 days of the year. 3 hours, twice daily- rain, sleet or snow.
Fancy equations are good and great. POWER, gained through years and years of excruciating daily, weekly, monthly, yearly work, for years on end: where cycling greatness lies.
When does the sock reaming commence?
in about a week. tests all done.
seriously, around 17:00 is that his tan line or a pair of white socks? I think its tan line due to muscle line.....
@@Hambini YASS finally
@@Hambini we still waiting)
@hambini Curious to understand why the Giro Aerohead ultimate is "faster" without vents when the regular Aerohead with vents could continue the attachment as described on the back like the Met helmet.
Hambini, my favor quote from my first boss after graduation (I'm an MechE with a masters) was "you can't train arrows.". Despite my thermodynamics background, he was critiquing somewhat nonsense representation of air flow. In essence he was saying "You can make all the PPTs with arrows on them to represent air movement that you want, but those arrows don't necessarily represent what happens in real physics." I quickly learned due to my background. I'm unsure if you're other experts have the background to learn. For example, one of my children has a physiology and exercise science degree. When I talk aerodynamics with her, she's lost. I won't generalize that all of the physiologist that direct wind tunnel tests are clueless, but when I see some wind tunnel aero tests, I tend to see lots of trained arrows.
Thumb up for trained arrows 👍
The model is only as good as the assumptions made.
@David McMillan Bachelors today are about as useful and qualifying as a high school diploma. You can tell who is fake or not based on the type of experience they've obtained afterward. That's why FLO cycling is a huge red flag. Two guys with bachelor degrees with no practical experience claiming to be aerodynamic experts.
What about analysing Graeme Obrees UCI banned old faithful & superman positions?
Obree knows alot about cycling. He'd be punching holes in this blokes theories left right and centre
Bottom brackets with less friction? What a load of rubbish
Part of the answer here : ruclips.net/video/oJ9H0INZ2_s/видео.html
@@oeympe thank you, Graeme Obree a true star, cheering to rewatch in these BS19 times.
his old faithful tuck position eliminates the undesirable space talked about at 20 mins. copied from downhill skiers, little doubt that it works.
Probably not
Hambini, I like your haircut! One might even describe it as...aerodynamic.
Hair-o-dynamic.
Hambini, I know I should be focusing on your content instead of your looks, but it needs to be said: Your Covid hair is looking majestic af.
Out of the popular manufacturers of triathlon bikes which one would you think has a better more "aerodynamically correct"/better bike..ie Scott Plasma (old/new rim/disc), Canyon Speedmax (old and new rim and disc), Specialized (rim and disc), Q-Roo, etc etc..
There are more than one yaw angle which one are we taking about ? Front wheel, helmet, the frame?
It hasn’t been commented that the video on TrainerRoad’s video where you got that screenshot of Mr Rossi is brilliant as hell
This statement, drag inversely proportion to yaw angle complementing the “time dilation” theory closely.
I see a lot of people referring to the drag equation what talking about when to get out of an aero position and move into a more powerful but less aero position (about 20km/h) am I correct in thinking that the 20km/h people refer to is net velocity rather than rider velocity so for example if you are riding into a 30km/h head wind you would always be better off staying aero and if you have a 30km/h tail wind you should almost always stay in a more powerful position (unless you are going over 50km/h)
That is not something I'm sure of. The companies paying for these tests don't make all of it very clear
one of your finest tutorials.
Did I just watch a half hour power point presentation on aerodynamics, and not fall asleep??? Chapeau Hambini
I love this video. I race TT’s, and can hold > 30mph for 10 miles so aero does have some effect at that speed. However, I went to a tunnel for the experience and to see the data. After I was there for about an hour testing positions, and “gaining watts” per the instructors, I asked how this equates to real world situations because the bike was in fact locked into a straight up and down position. They said that the rocking back and forth absolutely matters and people trying to find every last drop of aero gains are wasting time and money, and we had a laugh about my being there as well. You do have gains from being smaller on the bike (not necessarily LOWER, mind you), however, there’s a tradeoff to power output. I’ve reached a point where I have a “comfortable” enough position on the TT bike, and if I can do something to get more power out of my body, I’ll take that over alleged aero gains. Train more, core, flexibility, things that let you stay in your position LONGER, and without stress, will produce more gains. The worst thing I’ve done to do my own aero testing was throw my TT disc rear wheel and 80mm on the front of my road bike, and do a known 50 mile route, varying terrain, and my time/wattage/perceived effort was the same as my 1350 gram training wheels, within a few watts type of thing, not enough to matter. Could be bearings, could be perfect tiny amount of wind that skewed the data, but I can honestly say it made zero difference to me. Body position is key.
Yet the bike makers will tell (read SELL) you the idea the shape of your frame tubes matters...
@@Sills71 yupp, exactly. The width of a frame is what, 3 inches? Barely measurable. Take someone on the p5x that has their head popped up high vs someone on a steel road frame, no aero, but is fitted and lower, and yeah, there goes thousands of dollars down a toilet.
@@Sills71 There is probably an effect on pedaling stiffness depending on how frame tubes are shaped. But considering how little of the frame is actually exposed to headwind there is little argument to be made in how much you can improve frame aerodynamics for more forward speed. Crosswind could be a consideration but most road bikes seem to be optimized to catch as much crosswind as possible, the opposite of what you'd want...
Would you comment on aerodynamic of rim brake versus disc brake ?
What is better? To lower the bar extensions or remove the void of nothingness in front of your stomach and chest?
Lack of Princess Blanket - dobbed you in.
Potentially stupid unrelated question here... i would assume that wheel manufacturers design wheelsets to work together (front with back). When I ride with 2 mavic 60mms I seem to go fast, but when I have just the rear 60mm in I seem to be really sluggish. Is there a possibility that the non aero front wheel throws off the aerodynamics of the aero rear? Or is it a coincidence and it is purely placebo effect?
Well, the front wheel will likely matter a lot more. Since it's encountering clean-ish air, and often other things have disturbed the air by the time it gets to the back (once it's spoiled, spoiling it some more doesn't have as large of an effect.
If it was practical, the front wheel would actually benefit a lot more from a disc than the rear. The problem is that any kind of wind tries to throw the steering all over the place.
Hambini if you take a look at the position of Peak Torque, who is resting his arms on this thing that sits atop his steer, and you think that he is driving fast in that position, whilst the levers of his breaks are waaayyy down and to the sides, don't that give you some thoughts?
I was wondering, how much of an aerodynamic penalty do you have running disc brakes compared to rim brakes?
Thanks for creating the illustrations & explanatory information & going through it all in a perfectly ordered way. I'm not a time trailer but I do like watching time trials when they happen to be on tv like during the Tour. Be safe. 👍☮️🌞🦠😷🚲
In real life my speed is more or less constant so wouldn't the yawing back and forth simply appear to be an increase in Cd?
Not so sure about the helmet. I think the reason you see the shorter ones like the kask ones sky were using is because people generally don't look straight ahead all the time. Once you look down with that massive tail on the back it's miles worse.
slot/slat aerodynamics? Is that what Ridleys do on their FAST front fork of a Noah aero bikes?
Excellent point about the drag vs. yaw graphs not increasing the air velocity as yaw angle increases. (What's the point in modeling a stationary bike?)
I have no idea why they do it. Other than it is easier
Regarding basebar - aero bar separation. There's some data out there (CFD and wind tunnel, fwiw) that says that a gap of 40mm or more is more aero. So either have a big gap or slam the aero bars right down to the basebar. Also, some riders put the aero bars right at optimum position and have the base bars as low as they can go for handling around corners and technical descending - equivalent position to the drops on road bike. Not fond of that extended lever and extra shear force on longer bolts, and my TTs aren't technical. So haven't tried it myself.
I made a cnc cross brace (3mm thick 7075-t6) to tie the extensions together and take the bending loads off the long bolts.
Can you comment on how the aerospace industry uses wind tunnels for testing? If the parts are static for them how is it helpful?
if it's for civil aerospace, the aircraft is flying so fast that the effect of "wind" is negligible and ignored. If it's in military aircraft that are performing unsteady flight then it's a different kettle of fish and not one where I can comment..
@@Hambini except for take-offs and landings
Could you analyse graham obree different hour record positions thanks
Happy to see that my bikefitter - who is the biomechanical expert and not an aero expert - has fitted me right. A slight rise at the end of the aerobars to relieve pressure from my shoulders (which strangely resulted in more power) but no praying mantis (arms horizontal). He also minimized the spacers under the pads, he said 'you don't need it and many TT-rides add them because it looks cool' 🤪. Furthermore shorter cranks so my saddle could go up to get my back horizontal.
I did switch from the Giro Selector (long tail) to the Aerohead (short tail) because I couldn't keep a position in which the selector would stay between my shoulders, most of the times it would end up a few centimeters higher. Curious if it's really a problem?
If you shrug your shoulders you might be okay
following Hambini's channel I have learned so much !!
..all the bike tech stuff that my bike dealers never told me
..all the english vocabulary that my english teachers never told me 👍
I have several bikes set up the same, when I change bikes after I have ridden one for awhile, it takes me about a week to get used to it.
I have ridden them for years but find this always happens.
Love you aerodynamics video. Would love to see a no rules aero bike design by you. On the topic, couldn't we do "shapes"at skinsuit like motogp, because all chest airflow could maybe help at avoiding detachment at the back? And couldn't skinsuit be attached to helmet by imans or zip?
Is a low center of gravity actually more stable on a single-track vehicle? I've been experimenting with recumbent bikes, and generally the lower, and further forward you are, the more trail you need to make the bike feel stable. Bikes with a seat that's higher and further back are much less twitchy and hard to balance.
Would the 1993 Obree and the 1997 Pinarello Parigina still be fast bikes?
Hi Hambini. As a fellow aerodynamicist, I have to say that I love your attitude! Your analysis (through many of your videos) is mostly sound. I only say mostly sound, because I am also unconventional in many respects and have some differences of opinion to the mainstream aerodynamic opinion. That doesn't necessarily mean that I am right and I can say that I have learned a few things from your videos. I am in the strange position of having migrated from very high speed aerodynamics to working with quite low speeds. (ie < 70 knots). I also do a lot of cycling so your analysis interests me greatly. Keep up the good work.
When is that intro going to stop making my heart fall out of my arse...!?
Jean Paul Ballard has stated he sees marginal benefit in a disc wheel over his Swiss Side Hadron Ultimate 800 rear wheel at 45 km/h yaw-weighted at 45km/hr. Think he said up to 2 watts (and only 1 watt at 35 km/hr). Sounded like you thought there might be more? Why is a disc more beneficial for tall riders - stability related?! Funny how Rossi uses Giro older TT helmet and Peak Torque uses their new and improved supposedly faster by c.5w at 45 km/hr!! I know helmets are rider-specific though ;) Would love to see more of these videos - good work as always!!
Any chance you can remove spokes from the equation to avoid turblence, I think the better. If we could safely ride two disc wheels front and back, that would be the best. But a front disc wheel is highly unstable. On the track you do see double-disc wheels fairly often.
@@mikew466 Yes, I don't think there's much doubt at all that the discs are aerodynamically better than spoked wheels - I think the difference is between those who see 1 -2 km/hr difference between deep section spoked wheels and discs, and those who see considerably more
Double disc in the speed disciplines, Team pursuit, team sprint, but tri spoke when you need to manoeuvre, kerin, 1v1 spring, scratch race etc
Sure J-P B will tell you his product is wonderfull: he's trying to sell it.
Col Duncan he also said that they will bring out a disc wheel early 2021. Guess he would want to sell that one too ;)
You can give some rules of thumb based on intuition or general physical principles, make predictions with CFD (if looking for deltas on the order of 5--10% or greater), but at the end of the day, fluid dynamics is nonlinear so the only way to know for sure is to test. And yes, a wind tunnel measurement is just a more accurate (and expensive) way of predicting what will happen in the real world, but it is not that. Just because some shape looks sleeker, or seems like it has fewer features to induce early separation, doesn't necessarily mean it will be lower drag.
For TT wannabes like me.... ski extensions? S-Bend extensions? Straight? I can't really do straight (horizontal) extensions well because of numerous wrist injuries, but curious on what is preferable.
Very informative video and straight to the point!👍
Hey Hambini, nice video, I heard you are going to make a video about tire widths, is that true? keep it up!
Would it be better to fill that blue area in with highspeed lightweight fat?
Thank you. We need more of this sort of real world anti marketing wank information.
What WE really WANT is MORE SPEED. Shit that ACTUALLY WORKS. Most ppl fail 2 realize U R the MAIN source of DRAG and POWER. 4,000€ bike with a rider that makes 200 watts is NOT faster than a 1,000€ bike and 300watts.
this is fascinating but is it true? How come if the low hands position is more aero have we seen almost all riders move to a position with high hands or atleast much higher than flat/parallel hands to elbows?? Also why is the side on view looked at most with riders? surely the wind see's you from the front, and there we can see that getting as narrow as possible would be more aero aswell as having high hands to minimize the space between hands and helmet, so the air can maybe attach effectively and not hit into your stomach which would act as a parachute?
thanks hambini please let me know, i just want to get faster!
Another area that cycling aerodynamics have been pushing the past few years is a lower base bar, and a and higher aerobar with tall spacers. Like the Peak Torque guy's handlebars. Supposedly the air is cleaner because it can flow between the gap in the aerobars and the basebar. Whereas with the older setup of the basebar and aerobar together, there is a larger frontal area in that setup and the air is more turbulent. Is all of this really better? Who knows, but I've noticed pros follow trends, so if everyone starts using a certain position or bike setup, everyone copies each other.
@@mikew466 yes thats what i heard too about the base bar but obviously hambini thinks other wise
I think praying mantis is a biomechanical compromise. It trades a bit of aero efficiency for a lot more comfort and power.
The last time I got a new saddle I loved it immediately. No break in period required.
I guess I'm delusional.
Nah. I've found the same thing, sometimes. It might just be that the old saddle is bad, so removing the badness is "good" even if a lot of saddles would seem just as good.
I think probably more than a change in saddle, would be something like a change in saddle or bar position, which will feel "wrong" for some time, even if it's ultimately fine long-term.
Hi Hambini. Are you able to do a video where you explain why a lenticular disc wheel is faster than a flat rear disc wheel? Also, do aero overshoes make any difference or are they just a waste of money?
Peak Torque has a lot of similarities to Wout Van Aerts and also Rohan Dennis, size, position, bike and helmet too actually... Two of the fastes people on bikes in the world atm, Wout won the Belgian TT championship, and the iTT in the Dauphine, before he crashed in the tour. Campenaerts and Evenepoel are also fast of course, but they both have a different build and position (much smaller)
I wonder if they can really improve much, or if they basically have it right (because they are already winning the TT that they aim to win) They have a pretty high interest in getting it right and don't just listen to the cycling media, they work together with universities etc and do legit testing.
Hey Hambini, you mentioned that you can optimise your equipment for better aerodynamics.
No 2 was the handlebars - what would you recommend? I may have missed it in your previous videos or posts about handlebars. Cheers. Chris
Mr. Peak Torque has a video on handlebars.
Anybody wondered why GCN didn't collaborate with Hambini ever since their collaboration ? :)
Bikeo Matic I wonder?
Hambini, some say wider tyres roll faster. It sounds counter intuitive. Can you explain in a video?
Pretty informative, could you do a video about weight, inertia and how much it matter wether the weight is in the wheels or in the rider's belly ?
Marvel: Infinity War is the most ambitious crossover event in history
Hambini: ...
John Macaulay Hambini and GCN was pretty ambitious.
This is one of you better videos recently. More like this, less bullshit and personal attacks and more science.
Hambini could you please analyse velomobile aerodynamic comparing alpha 7, after 7, milan Sl and snoek ? That are normally the top of the line on aero for velomobile. The velomobile community will be please to have out of the box thinking... Thanks for your video.
with respect to your recommendation that wheels be fitted close to the frame to prevent voids/turbulence, how do you think the ventum tri bike performs aerodynamically? (yes it looks like monkeyspunk).
Would there be a difference in drag between having vents in front of the helmet or not when the head is in a low and good position such as what Rossi has? For example, does it give Bell Javelin that have vents in front of the helmet more drag than it would without those vents?
Hey Hambini.. Another great video! Wanted to ask a question about changing aero wheels. I'm currently using Lightbicycle R45, they are 45mm deep, 25 external, 18 internal. I'm thinking about Lightbicycle AR56, so 56mm deep, 30 external. Model/make doesn't matter but I wanted to ask your thoughts on how much extra 11mm in depth and slightly wider would help?
You scared my cat. LMAO! She was walking up to me just as you said "Hello Hambini fans!!" She took off!
About flow separation. Does the trailing edge of a wheel significantly contribute to drag. And if so would using and symmetric ovaloid shape on a rim tire combo help with that?
Compared to what the air's had to do before getting off the back tyre to let the rider's body through, I can't see the trailing edge of the back wheel making any usable difference. Also the shape of the tyre has to follow a completely separate set of constraints, namely that it needs to grip the ground and that it's a thin walled pressure vessel holding back a constant pressure on its inner surface, so it will always choose its shape in response to that load.
Adding reinforcement to the tyre to change its shape is a possibility - specifically filling in any dig between the rim and the sidewall might be an option (Some wheelsets are doing this to some degree already I think), but the trailing edge of the tyre is the tyre tread, so unless you can make changes without impacting grip and comfort on rough surfaces, it's a big ask that I'd be amazed to see produce a useful payback.
Nicely explained. I do have a question though. I use a Kask Bambino TT helmet with a visor. I do own a Specialized full aero helmet too and use a nopinz skin suit with the number concealed. For real world conditions, in your opinion as a well respected five year old, which do you think is best helmet wise? I wear Oakley Radars with the Specialized lid by the way.
Thanks, Steve.
Kask bambino helmet was developed for Chris Froome and his head is all over the place.
At 21:54 I completely lost track of what you were saying because your pen was distracting my squirrel-brain. I need to watch that part again, thanks.
I've been experiencing dutch roll while riding. Is this due to poor body position or because I'm cycling while pissed?
Is that anything like Dutch rudder?
“Assume everyone is a fucking idiot until proven otherwise”
*thinks about the words coming out of Hambini’s mouth at that very moment*
Good explaination. Makes things more clear.
Love the videos and the presentation style, quality!
Superb, how bout you do some vids on the claimed aerodynamic benefits of different bike models? Would be great fun...
I've pressed spacebar to pause the video so I could get myself a bowl of some delicious rice and a popup message appeared: "Added to Liked videos". Damn those computers are so smart these days.
Haha! You never fail to try get us jumping off the seat bro. Well done on another entertaining edition of cutting down the weeds.
Excellent thank you.
Great Hambini, is the frame (carbon frame) on a 2015 R2 Cervelo any good, how about the BB as I am having a new old stock bike put together for me so test drive. The price is Thanks !Chris from Canada.
Cervelo is not the greatest manufacture around, and that is being generous.
More aero advice for useless laymen like me, please :) I'm still trying to determine if horizontal arms allow me as good power generation as raised (mantis) setup. Maybe just a case of getting used to it?
yup...like paying taxes!!! 😙😜😝
These videos always crack me up 😂
Hambini when are you gonna finish the charity shop aero bike???!!!’
Hello Hambini 5yo ! Just wondering, most of the time there is not much wind outside (
Rider oscillation is quite significant
Rider oscillation is quite significant
Have you seen the 'wind tunnel' app on the apple App Store. Show airstreams and the turbulence caused as the wind goes around it. very basic but good way to illustrate airflow behaviour.
does a disc wheel not generate a shitton of drag when the wind is not perfectly parallel with the movement?
Don't forget that the rider is moving forward at a reasonable speed, so the overall vector of the flow will be from a generally fore/aft direction. Unless it's really blowing a hooley in which case you're in for a bumpy ride anyway :-)
Do you think you could do a review of some road bike helmets that are aero as people can wear TT helmets all the time
With your arms in the low TT position should you try to have them together or slightly apart creating a slot affect and so reducing the low pressure behind your upper arms?
In an alternate universe Hambini and Malcolm Tucker are best friends.