Follow up video-Could one get the same "make the bike feel like its on a canal path" result by 1) Tipping saddle 2) Move saddle forward 3) Lower handlebar 4)Lengthening stem?
Wondering if it makes any difference to put a 650B on the front of a climbing bike, and 700C on the back - with same tires etc. - compared to a 2 x 700C wheels. And would it be UCI legal in a race.
Would a 60 tooth chainring even fit? That's more or less what my folding bike did to get a useable speed range on a 20" wheel, and even then useable is spinning out somewhere in the mid-20mph range.
I love these experiments! Now do the opposite with Andrew Feather. He likes climbing out of the saddle so put a small wheel on the back and see if he goes any faster on the flats.
Connor, you need to compensate for the change in the fork trail by reducing the headtube angle as the front wheel diameter is reduced. This experiment made each smaller wheel steering more twitchy by reducing the fork trail. The alternative would be a fork with more rake to maintain the trail. The logic of maintaining the steering / handling will influence your confidence to apply power.
I live in a very hilly area with lots of 9-15% climbs, so this is an interesting idea to me. I have a few different size wheels that I could swap out to see how this works around here.
I live in a hilly area too. I find I can go uphill easier on my 20-inch wheel bike (20 at the front and 20 at the back!). Maybe part of the reason is that it seems quicker to revolve the cranks back up to their high position, thereby being able to exert downward force on the pedals quicker and more often than I can do on my 700c bikes.
Rotational Mass is a big issue on very steep climbs. If you are constantly accelerating a wheel back up to speed (as when you are out of the saddle "pedalling squares" on a steep climb) then a large diameter wheel will take more power than a smaller diameter to spin up to speed. Multiply this by the number of pedal strokes you use and it can be quite significant. That's why I'd go for the very lightest rim & tyre on a Hill Climb bike. An Aero rim & tyre combination are more beneficial on the flat, where you aren't constantly accelerating with every pedal stroke. That 36" wheel and fat tyre combination (never mind the knobbly tread pattern) is a big old rotational mass to keep spinning up to speed. It's a big flywheel, which may be useful on a 1 hour track record attempt, but not at 5 mph on a steep hill.
I was thinking along the same lines, he would have probably done better with a smaller wheel like a 27.5 or 26 on the back and a 20 front. And maybe some lower gearing.
The heavier wheel will also have more inertia and acts like a flywheel (more energy store=slower decceleration). Of course lighter wheels are an advantage in climbs but I don't think it has to do with inertia but just added weight.
I love seeing GCN do this kinda thing ... I do silly things as I can (like the drop-bar fatbike in my profile), but there few folks that have the catalog of bikes/parts to do what GCN does. Thanks and keep it coming!
I think the key difference you’ve shown is the position over the bb makes a pretty big difference. I read some discussion about Pogacar changing his fit last offseason to have a more forward position on the bike so on very steep climbs like he can be more comfortable and potentially produce more power. I think a device to change your seat position would be really interesting. Like a dropper post but forwards and upwards.
@@Aniqa101exactly, the standard position would be the rear and then you’d pull the saddle forward whenever you’d be on TT bars for long enough periods of time
I now ride my Gravelbike with a 650b/27,5" wheel in the back and 700c/29" in the front. This gives me a shorter gear ratio in the back, as the total wheel diameter is smaller. I really feel it gives more confidence and grip on loose gravel when going downhill, as the effective angle of the bike is a little slacker, but makes weirdly a big difference. And it has now waaay more grip in the rear, as the tire is wider too. I now can stand up on loose or wet steep gravel uphills, where i before needed to stay seated. Rolling resistance got better too, with a Continental Race king in the back probably without an aero penalty. I can fully recommend 2 different wheel sizes, but the other way round as in the video. ;)
Hmm... My "gravel bike" is a 26" mountain bike which I modified by getting rid of the front suspension and mounting dropbars and road shifters. I could easily put a 29" wheel with 2" tires in the front end. We have a lot of very loose gravel on our roads around here, so anything that would make the downhills feel more in control would be welcome. The 26" wheel in the back is definitely a help for climbing.
never quite understood why on mtbs a 29" in the front and a 27.5" is called a mullet - if anything thats a reverse mullet... now this monstrosity is a real mullet bike! :D
@@alfonshasel1995 a mullet is business in the front (short), party in the back (long). an mtb mullet is party at the front, business in the back. now imagine that for a hairstyle :D
I would love to see the monster bike versus a unicycle 36er. At most everything unicycles are not particularly competitive but for climbing I feel like they have an advantage.
I’m not sure. We had a guy enter our university club’s hill climb competition on a unicycle, many years ago. I think it’s fair to say that whatever advantage a unicycle may have offered, he failed to capitalise on it, coming last by quite a margin. Then, just for fun, we disqualified him, based on our reading of the RTTC rules on how many brakes he was supposed to have. 😂
@@Steve.M Surely the rules state that each wheel must have a brake, so one wheel, one brake? Of course, if the rules explicity state "bicycle" it must have two wheels.
hahah yes not going to lie, I did have one too many coffees when thinking this idea up.. Load of fun filming and personally, a surprising conclusion too!! Thanks for watching
Really enjoyed this video by Connor. I was fascinated by the results and wonder whether we will see any one off specials emerge for hill climbing ( I have the impression that the rules on bike spec are much more relaxed for hill climbs? ). Great video, and Connor was the perfect presenter for this challenge.
When I was a kid I used to put a 20" BMX wheel with knobby tires on the front of my road bike (26" tires) sometimes just for kicks. It did seem to be a little easier to pedal up hills (I grew up in a very hilly town), and it seemed more stable and controllable on rough dirt roads. The main problem was no front brakes (the fork crown mounted rim brake couldn't reach the 20" wheel of course, and even if it could have, the distance between the pads was too small to fit onto the 1.75" wide BMX rims).
I think this is brilliant. Yes, it's a bit of fun and makes a great video, but it's also the kind of creative thinking that can lead to advances. If you have an idea like this, you've got to check it out. The worst that can happen is it doesn't work but you have a bit of fun. If it does work ... who knows? Go Conor! 😆
I put a suspension fork on my ridgid mountain bike, which increased the trail number and raised the front end a bit. It's definitely harder to climb the steep stuff with the new configuration.
Steep seat tubes has been a revolution in MTB for people who ride in real steep places, 78 sta and a long wheelbase is the best, I run 24x51 as well which is the business, drop forks were really nice for this in the past as well!
Really enjoyed your experiment & I certainly need help on the climbs! Take a look at '1984 Olympic Team 100km Funny Bike' & I think you'll have what you need for the next stage, It'll have 18mm tubs on as well which might help. Maybe something smaller than a 66t chainring ..... - Raleigh at the cutting edge!!
Conor, you are always entertaining no matter what you are doing. I experiment with the inverse of this on the trainer all the time with a front wheel angle block that puts you into various climbing postures and it does make a difference. Your method seems more fun.
There's a lot of sense in this. Physics of the situation on the incline ofc means that the ideal vehicle for any given gradient would have different geometry when designed specifically for that aspect of traverse. If you had a bike that could magically grow and shrink the radius of it's wheels and alter height and angle of saddle post/handlebars to fit the dynamics of a situation you ofc would utilize that feature and not ride on static frame. The best static design is always a compromise that account for the overall use situation, not the best design for any specific dynamic.
I work as a messenger and collegues of mine have developed some kind of mini cargo bike with 20" front wheels. They extend their forks so the overal position is the same but by lowering their the top of their wheel they are able to have a really deep front rack
A nooby here so excuse what you may think as silly questions. What are the rules on the Grand Tours? Are teams allowed to vary wheel sizes with their 8 team members? On a stage with a long, steep climb would it not be advantageous for the the teams top climber(s) to maybe have the front wheel 1-2" smaller than the back so they have a small mechanical advantage on the climb? It seems to me that the name of the game in these big races is the concept of marginal gains - so if a team ( member ) could have a 1-2% advantage in efficiency when climbing would this not make sense to do? OR ... would the advantage going uphill just be lost on the flat / downhill sections?? Great vid by the way - I like Conor's light hearted approach to life / cycling.
Great experiment; I’ve wondered about that myself. I also wondered about the descent, but Connor added that bit in, too. From a practical perspective, would a road bike “mullet” bring any real benefits in a mixed elevation ride? The clear benefit on a climb would be more than offset in flats and descents, making it a “curiosity“ rather than a normal setup. But I certainly see some of the hill-climbing specialists-who compete in climb-only events-incorporating some of this into their setups.
Great video! The idea however, is not new: my old 26" Stevens MTB, with RockShox Reba front fork, could do it! You could adjust the working length of the telescope, and at the same time reduce the height of the front by several centimeters. This feature and the lockout together made climbing more comfortable and more efficient.
great video, but surely the smaller wheels help cos of less weight too, so you should be carrying the weight difference, so you and bike have the same total weight at the start to the finish
A very moderate "smaller wheel in front" idea for Andrew Feather in an uphillrace is to make a tiny difference , using larger tyre behind. He could have a 21mm wide tyre in front and a 28 mm tyre behind.
Thinking about trying 27.5 wide front wheel and a 700c back wheel. The theory would be the wider tire for taking on road bumps while keeping the feel of the 700c for power. Since my gravel frame came with both wheelsets, it might be worth trying.
Moulton bikes have for decades made high end bikes with small wheels. Reduced rotational inertia relative to standard wheels makes the bikes feel more responsive, seemingly accelerating more quickly perhaps. I believe smaller wheels have less aero drag (at least in isolation, not sure about total bike system). Perhaps a more 'typical' feeling body position relative to gravity direction (small front wheel on steep incline) enables the rider to feel comfortable working closer to the limit as opposed to working at the limit when positioning and handling are unfamiliar and uncertain.
Tire rolling resistance scales just like slope or gradient, so you want the lowest possible rolling resistance. I haven't measured the rolling resistance of small diameter tires in a while but, in general, small diameter tires aren't designed for the lowest rolling resistance.
Imagine the Tour de France with a mountain top finish where a bunch of riders switch to a bike like this at the bottom of the final climb. They swap bikes in a TT that goes uphill so not out of the realms of possibility where pros are looking for every marginal gain. They could even just swap out the front wheel for that matter rather than swap bikes!
Yeah, I have a problem with steep climbs. There is one nearby with a hairpin bend in mid climb. Going up and turning in the hairpin makes me feel like I'm extremely close to falling off my bike and tumbling down the hill. I hate this feeling...
I’ve been tinkering w/ the idea of a tandem built for a woman who weighs about half what her Yeti weighs. It’s always seemed to me that the more powerful of the two on a tandem should be the stoker, & it’s not like a woman can’t steer or decide when she needs the brakes or otherwise “captain” the vessel. Anywho, that’s had me thinking along the lines of a 700C rear wheel, or maybe a 29er w/ a 650B up front & not a lot of bottom bracket drop for a fairly up-there-tall position, especially in the back - maybe place the bracket heights at or just below a line between the spindles w/ the top tube(s) parallel to that line, etc.
You might want to try this with a regular fork, I think the 20" wheels won't even be necessary to get the full effect. I'm curious if such a construction is UCI legal, especially in regards to the saddle being very far forward on the flat.
Have to invent a bike with an extendable fork. You could adjust down when climbing and back on the flat. But front wheel will need to be smaller always. Maybe 24-27 set up.
Answer = Telescoping forks with an intermediate sized wheel (e.g. 24...22?) that is effectively that small when raised and is "normal" when extended for the flat, or even effectively larger for going downhill.
Over several years i tried to compare the speed of a racing bike with an recumbent bike at a 2.5km long hill with about 7-8% gradient. The difference was less than 5%. Both bike were about 10Kilo and the Bent has bader tires. so i assume more rolling resistance for the recumbent and the reasons for the slightly lower speed. My result: when you are used to the riding position all bikes have equal speed. So i am astounded over your huge speed difference.
I think there is one part you didn't look at: tires. Those 27.5 mtb wheels had downhill tires. The 20 inch wheel also had rough tires. El alto has more like xc mtb tires, these have less rolling resistance. Should have used similar tires on El alto as well, or other wheels with more xc type tires to match El Alto. Fun experiment though!
You see this sort of miss-matching wheels in a lot of recumbents, though they have their frames made so that the body position is ergonomic and aerodynamic.
Maybe not only the wheels make a difference when going uphill but also the groupset. If you switch from the Shimano Dura Ace groupset to the Shimano Viagra groupset, you might go upwards quite faster - and longer.
Interesting! Now please do a comparison between riding this and riding the same climb indoor with Kickr Move but _without_ Kickr Climb. Because this looks a lot like climbing usually feels while riding indoors.
When I clicked I was expecting to see some sub 5 kg carbon bike you borrowed from someone at the Hill Climb champs'. I was not expecting THAT 😮. p.s. Conor will be receiving the cleaning bill to get the mouth full of coffee I spat across my living room out of the carpet.🤣
Fascinating outcome. However, I do feel that this needs further investigation, such as Connor repeating the experiment on different bikes. Would a 700c rear wheel match with a narrow small front wheel? What about an adjustable fork, like a variable travel suspension fork to change the head angle when going into the climb? Maybe get your tame hill climber to check this one out too to see if it has an impact on his times too? Would a lab based climbing rig be suitable to test this? Great work Connor and GCN, just don't let the UCI seeing you playing like this, they might have a sulk! 🤣
i think you were faster because the 20 inch wheel was just lighter maybe? awesome video tho!!! it seemed so funny to ride on flats but climbing uphill 😂
to optimize it, you'd probably want to switch both fork and wheel to get your axles level. you'd end up with a larger wheel to get the same axle angle as you'd lose the height from empty fork space.
Would be interesting to see something like this replicated on Zwift on a KickR Bike or climb set up. Same climb, one with the gradient switched on, then again with it off. Same principle surely. Position on the bike making it easier to generate power in your favoured and regular position. Obviously nothing like real world, but curious to see now,
Have Conner do a video comparing the Endurace vs Ultimate vs Aeroad (climb vs flat). Should be interesting to see how the Endurace competes against the race bikes
if you spun the fork around backwards, it might give back some trail that you lose from having such a steep head tube angle when you drop the front end. I'm not sure if the brakes would work well turning backwards, and you would be further shortening the wheelbase, but it would probably feel a lot less twitchy.
My hope is for a day when bikes are custom built for each rider in a cost effective way, and that would include the availability of numerous wheel sizes to give everyone more or less the same range of frame angles. Custom built bikes aren't terribly expensive even today, especially when compared to off-the-shelf high end racing bikes, so the only thing missing is ease of wheel and tire selection. It shouldn't be so much harder to fit someone who is 5' tall relative to someone 6' tall when they are proportionally identical to each other.
I think the Feather has to be involved, perhaps a climb he has the KOM on and a slightly more refined bike 700c with a slick 20" out the front 🤔. All in the name of science of course.
With the British hill climb champs just behind us, it would be interesting for Andrew Feather/GCN to experiment with a 650b wheel on the front (seeing as he's switched over disc brakes) to see if the mixed wheel thing has an effect.
Looking good. This Farty Phenning... Kinda enjoys the very scientific approach. As opposed to Blakes Reverse Mullet video over at GMBN, which seem to be more of a fun experiment :)
I have thought about experimenting with different size wheels but then I remember that time I drove through Texas with all the lifted trucks I could hardly see around
Very interesting, funny 😂 and educational. It would be interesting to discover how it fairs on the flats and downhills to give the complete picture. It could an option to change for the pros to change to a smaller front wheel for a uphill section. 😃
Nice video Conor. Next give the bike to Andrew Feathers to ride it. Would like to see Andrew Feathers riding this bike and a Fixie, as a uphill challenge.
Do you think Conor is onto something with his mixed wheel bike? 🤔
I think he's on magic mushrooms.🤣🤣🤣🤣
no
Follow up video-Could one get the same "make the bike feel like its on a canal path" result by 1) Tipping saddle 2) Move saddle forward 3) Lower handlebar 4)Lengthening stem?
Wondering if it makes any difference to put a 650B on the front of a climbing bike, and 700C on the back - with same tires etc. - compared to a 2 x 700C wheels. And would it be UCI legal in a race.
@gcn He should have a telescopic front fork, so it is normal on level ground!
Awesome video! Now you have the do a downhill speed run with the wheel sizes reversed.
Not sure GCN has insurance coverage for this 😅
Hahahah don't you worry... the cogs are spinning ⚙
That's ok, you can use Hank for it.@@allanguignard4204
Would a 60 tooth chainring even fit? That's more or less what my folding bike did to get a useable speed range on a 20" wheel, and even then useable is spinning out somewhere in the mid-20mph range.
Could stability be an issue decanting with a smaller wheel on back??
I love Conor's enthusiasm. He just is living his best life and sharing it with us. Always lighthearted fun! And I'm glad he didn't need water...
Never a dull day with Conor 🙌
Thank you - this was a lot of fun to film ha.. always a good day when El Alto is out on the roads!!!
I love these experiments! Now do the opposite with Andrew Feather. He likes climbing out of the saddle so put a small wheel on the back and see if he goes any faster on the flats.
Hahahah that would be great! 🙌
It would certainly be lighter.
😂
The most amazing thing to me is Conor still has to run a fair amount of Seatpost on that frame. 😲😲
It’s compact geometry, right?
Connor, you need to compensate for the change in the fork trail by reducing the headtube angle as the front wheel diameter is reduced. This experiment made each smaller wheel steering more twitchy by reducing the fork trail. The alternative would be a fork with more rake to maintain the trail. The logic of maintaining the steering / handling will influence your confidence to apply power.
You need less rake to maintain the trail, not more.
Expect to see these at next year's National hill climb championships
Watch this space! 😂
Excellent!!! Time to get Andrew Feather to try out a few combinations?!!😊
I live in a very hilly area with lots of 9-15% climbs, so this is an interesting idea to me. I have a few different size wheels that I could swap out to see how this works around here.
Good luck with your experiment!
I'm curious what will happen tbh 😁
I think downhill will feel as twice as steep😂
I live in a hilly area too. I find I can go uphill easier on my 20-inch wheel bike (20 at the front and 20 at the back!). Maybe part of the reason is that it seems quicker to revolve the cranks back up to their high position, thereby being able to exert downward force on the pedals quicker and more often than I can do on my 700c bikes.
@@TheShotenZenjintire size affects gearing
Let us know if any experiments have taken place already! :D
Rotational Mass is a big issue on very steep climbs. If you are constantly accelerating a wheel back up to speed (as when you are out of the saddle "pedalling squares" on a steep climb) then a large diameter wheel will take more power than a smaller diameter to spin up to speed. Multiply this by the number of pedal strokes you use and it can be quite significant.
That's why I'd go for the very lightest rim & tyre on a Hill Climb bike. An Aero rim & tyre combination are more beneficial on the flat, where you aren't constantly accelerating with every pedal stroke.
That 36" wheel and fat tyre combination (never mind the knobbly tread pattern) is a big old rotational mass to keep spinning up to speed. It's a big flywheel, which may be useful on a 1 hour track record attempt, but not at 5 mph on a steep hill.
I was thinking along the same lines, he would have probably done better with a smaller wheel like a 27.5 or 26 on the back and a 20 front. And maybe some lower gearing.
The heavier wheel will also have more inertia and acts like a flywheel (more energy store=slower decceleration). Of course lighter wheels are an advantage in climbs but I don't think it has to do with inertia but just added weight.
I love seeing GCN do this kinda thing ... I do silly things as I can (like the drop-bar fatbike in my profile), but there few folks that have the catalog of bikes/parts to do what GCN does. Thanks and keep it coming!
I think the key difference you’ve shown is the position over the bb makes a pretty big difference. I read some discussion about Pogacar changing his fit last offseason to have a more forward position on the bike so on very steep climbs like he can be more comfortable and potentially produce more power.
I think a device to change your seat position would be really interesting. Like a dropper post but forwards and upwards.
It already exists. Dual-position seatpost. Switches saddle offset.
Redshift does offer a seatpost like this, originally purposed for switching between road bike and TT position.
@@Aniqa101exactly, the standard position would be the rear and then you’d pull the saddle forward whenever you’d be on TT bars for long enough periods of time
I love it that Connor is always up for the daftest ideas they come up with. Nicest bloke on GCN. 🙂
aw thanks Jerry!! Feel very lucky at all the fun I get to have on the channel
I now ride my Gravelbike with a 650b/27,5" wheel in the back and 700c/29" in the front. This gives me a shorter gear ratio in the back, as the total wheel diameter is smaller. I really feel it gives more confidence and grip on loose gravel when going downhill, as the effective angle of the bike is a little slacker, but makes weirdly a big difference. And it has now waaay more grip in the rear, as the tire is wider too. I now can stand up on loose or wet steep gravel uphills, where i before needed to stay seated. Rolling resistance got better too, with a Continental Race king in the back probably without an aero penalty. I can fully recommend 2 different wheel sizes, but the other way round as in the video. ;)
Hmm... My "gravel bike" is a 26" mountain bike which I modified by getting rid of the front suspension and mounting dropbars and road shifters. I could easily put a 29" wheel with 2" tires in the front end. We have a lot of very loose gravel on our roads around here, so anything that would make the downhills feel more in control would be welcome. The 26" wheel in the back is definitely a help for climbing.
never quite understood why on mtbs a 29" in the front and a 27.5" is called a mullet - if anything thats a reverse mullet... now this monstrosity is a real mullet bike! :D
Iirc because the front is high and the back is low. Completely counterintuitive, but something along these lines
@@alfonshasel1995 a mullet is business in the front (short), party in the back (long). an mtb mullet is party at the front, business in the back. now imagine that for a hairstyle :D
I would love to see the monster bike versus a unicycle 36er. At most everything unicycles are not particularly competitive but for climbing I feel like they have an advantage.
yas
I’m not sure. We had a guy enter our university club’s hill climb competition on a unicycle, many years ago. I think it’s fair to say that whatever advantage a unicycle may have offered, he failed to capitalise on it, coming last by quite a margin. Then, just for fun, we disqualified him, based on our reading of the RTTC rules on how many brakes he was supposed to have. 😂
Disqualifying him is a dick move. ngl
@@stefans4562 Yes. A dick move between mates over a few post-ride beers. No harm done!
@@Steve.M Surely the rules state that each wheel must have a brake, so one wheel, one brake? Of course, if the rules explicity state "bicycle" it must have two wheels.
Connor always has the best video ideas, can hardly wait to see what comes next. Great video, had me laughing and thinking the whole time.
It’s probably the big wheel distorting my scale of size. But I feel that bike needs a MTB 12sp cassette with a larger top gear for climbing
Surely you want a lower gear for climbing? And you'd be on the bottom gear, not the top.
Do this again with Andrew Feather using lighter road wheels and tires. Maybe try 700c in the back and a 16" Brompton wheel in the front.
This ranks up there with the “let’s see how much coffee we can drink out on a ride” video for it’s ridiculousness and I’m all for it.
hahah yes not going to lie, I did have one too many coffees when thinking this idea up.. Load of fun filming and personally, a surprising conclusion too!! Thanks for watching
Who's Idea was this???
Really enjoyed this video by Connor. I was fascinated by the results and wonder whether we will see any one off specials emerge for hill climbing ( I have the impression that the rules on bike spec are much more relaxed for hill climbs? ). Great video, and Connor was the perfect presenter for this challenge.
Thanks Peter!! Yes, I definitely think there is scope for different wheel sizes in hill cimbs.... I'll see if I can persuade Feather for a trial run!
When I was a kid I used to put a 20" BMX wheel with knobby tires on the front of my road bike (26" tires) sometimes just for kicks. It did seem to be a little easier to pedal up hills (I grew up in a very hilly town), and it seemed more stable and controllable on rough dirt roads. The main problem was no front brakes (the fork crown mounted rim brake couldn't reach the 20" wheel of course, and even if it could have, the distance between the pads was too small to fit onto the 1.75" wide BMX rims).
Missed this when it came out. My favourite GCN video of all time. Great stuff.
I think this is brilliant. Yes, it's a bit of fun and makes a great video, but it's also the kind of creative thinking that can lead to advances. If you have an idea like this, you've got to check it out. The worst that can happen is it doesn't work but you have a bit of fun. If it does work ... who knows? Go Conor! 😆
What Mike Burrows was all about.
I did this years ago
Yes it helps on very steep slopes when it gets hard to keep your cg over your wheelbase.
What’s amazing is that El Alto doesn’t look too big for Conor 😳
Yeah, it's only noticeable when you see him next to the other presenters 😂
Juuuuuust right 😂
I’m his height and have a 36” wheeled bike. It’s so fun to look down at the ants riding around me on their little 700c wheel bikes. 😂😂😂
Only Conor can make El Alto look correctly proportioned.
Because ElAltos is a “fully bespoke” bike, hand crafted and made-to-measure specifically for Conor.
I put a suspension fork on my ridgid mountain bike, which increased the trail number and raised the front end a bit. It's definitely harder to climb the steep stuff with the new configuration.
Optimizing your weight distribution is always key. Very cool experiment.
Such an entertaining presenter. Always love a Conor video
Steep seat tubes has been a revolution in MTB for people who ride in real steep places, 78 sta and a long wheelbase is the best, I run 24x51 as well which is the business, drop forks were really nice for this in the past as well!
Really enjoyed your experiment & I certainly need help on the climbs! Take a look at '1984 Olympic Team 100km Funny Bike' & I think you'll have what you need for the next stage, It'll have 18mm tubs on as well which might help. Maybe something smaller than a 66t chainring ..... - Raleigh at the cutting edge!!
Awesome video, could call Feathers for a remake of this experiment
Mixed Wheeled Feather 🪶
Conor, you are always entertaining no matter what you are doing. I experiment with the inverse of this on the trainer all the time with a front wheel angle block that puts you into various climbing postures and it does make a difference. Your method seems more fun.
imagine how much faster with a small slick tire!
There's a lot of sense in this. Physics of the situation on the incline ofc means that the ideal vehicle for any given gradient would have different geometry when designed specifically for that aspect of traverse. If you had a bike that could magically grow and shrink the radius of it's wheels and alter height and angle of saddle post/handlebars to fit the dynamics of a situation you ofc would utilize that feature and not ride on static frame.
The best static design is always a compromise that account for the overall use situation, not the best design for any specific dynamic.
Saw this setup, different wheel sizes, many years on bike being ridden up the Maui Haleakala volcano (3050m)
I work as a messenger and collegues of mine have developed some kind of mini cargo bike with 20" front wheels. They extend their forks so the overal position is the same but by lowering their the top of their wheel they are able to have a really deep front rack
This gave me ideas. Changing my road bike front fork to higher would adjust the head angle to more relaxed and also the driving position.
would be nice to compare all your (GCN) experiments on the same hill with the same power output (old, new, cheap, super bike, wheels, weight, etc).
A nooby here so excuse what you may think as silly questions. What are the rules on the Grand Tours? Are teams allowed to vary wheel sizes with their 8 team members? On a stage with a long, steep climb would it not be advantageous for the the teams top climber(s) to maybe have the front wheel 1-2" smaller than the back so they have a small mechanical advantage on the climb? It seems to me that the name of the game in these big races is the concept of marginal gains - so if a team ( member ) could have a 1-2% advantage in efficiency when climbing would this not make sense to do? OR ... would the advantage going uphill just be lost on the flat / downhill sections?? Great vid by the way - I like Conor's light hearted approach to life / cycling.
Great experiment; I’ve wondered about that myself. I also wondered about the descent, but Connor added that bit in, too.
From a practical perspective, would a road bike “mullet” bring any real benefits in a mixed elevation ride? The clear benefit on a climb would be more than offset in flats and descents, making it a “curiosity“ rather than a normal setup. But I certainly see some of the hill-climbing specialists-who compete in climb-only events-incorporating some of this into their setups.
That was genuinely wild! Great work!
Great video! The idea however, is not new: my old 26" Stevens MTB, with RockShox Reba front fork, could do it! You could adjust the working length of the telescope, and at the same time reduce the height of the front by several centimeters. This feature and the lockout together made climbing more comfortable and more efficient.
great video, but surely the smaller wheels help cos of less weight too, so you should be carrying the weight difference, so you and bike have the same total weight at the start to the finish
Congrats, you have reinvented the Chopper. I saw someone just rode the Swains Lane hillclimb on a Chopper bike so there must be something in this!
Can competitors in UK Hill Climbing Events use different sized wheels (on the same bike)?
A very moderate "smaller wheel in front" idea for Andrew Feather in an uphillrace is to make a tiny difference , using larger tyre behind. He could have a 21mm wide tyre in front and a 28 mm tyre behind.
Thinking about trying 27.5 wide front wheel and a 700c back wheel. The theory would be the wider tire for taking on road bumps while keeping the feel of the 700c for power. Since my gravel frame came with both wheelsets, it might be worth trying.
Moulton bikes have for decades made high end bikes with small wheels. Reduced rotational inertia relative to standard wheels makes the bikes feel more responsive, seemingly accelerating more quickly perhaps. I believe smaller wheels have less aero drag (at least in isolation, not sure about total bike system). Perhaps a more 'typical' feeling body position relative to gravity direction (small front wheel on steep incline) enables the rider to feel comfortable working closer to the limit as opposed to working at the limit when positioning and handling are unfamiliar and uncertain.
Tire rolling resistance scales just like slope or gradient, so you want the lowest possible rolling resistance. I haven't measured the rolling resistance of small diameter tires in a while but, in general, small diameter tires aren't designed for the lowest rolling resistance.
I love Connor always signing up to do the ridiculous tasks!
Imagine the Tour de France with a mountain top finish where a bunch of riders switch to a bike like this at the bottom of the final climb. They swap bikes in a TT that goes uphill so not out of the realms of possibility where pros are looking for every marginal gain. They could even just swap out the front wheel for that matter rather than swap bikes!
Yeah, I have a problem with steep climbs. There is one nearby with a hairpin bend in mid climb. Going up and turning in the hairpin makes me feel like I'm extremely close to falling off my bike and tumbling down the hill. I hate this feeling...
I’ve been tinkering w/ the idea of a tandem built for a woman who weighs about half what her Yeti weighs. It’s always seemed to me that the more powerful of the two on a tandem should be the stoker, & it’s not like a woman can’t steer or decide when she needs the brakes or otherwise “captain” the vessel.
Anywho, that’s had me thinking along the lines of a 700C rear wheel, or maybe a 29er w/ a 650B up front & not a lot of bottom bracket drop for a fairly up-there-tall position, especially in the back - maybe place the bracket heights at or just below a line between the spindles w/ the top tube(s) parallel to that line, etc.
You might want to try this with a regular fork, I think the 20" wheels won't even be necessary to get the full effect. I'm curious if such a construction is UCI legal, especially in regards to the saddle being very far forward on the flat.
A new idea for the GCN's only Mr. Feather? 🤔
Would be nice to see if similar geometry would allow him to smash even more KOMs. 😂
What an interesting and unexpected question and experiment!
Have to invent a bike with an extendable fork. You could adjust down when climbing and back on the flat. But front wheel will need to be smaller always. Maybe 24-27 set up.
Answer = Telescoping forks with an intermediate sized wheel (e.g. 24...22?) that is effectively that small when raised and is "normal" when extended for the flat, or even effectively larger for going downhill.
Over several years i tried to compare the speed of a racing bike with an recumbent bike at a 2.5km long hill with about 7-8% gradient. The difference was less than 5%. Both bike were about 10Kilo and the Bent has bader tires. so i assume more rolling resistance for the recumbent and the reasons for the slightly lower speed. My result: when you are used to the riding position all bikes have equal speed. So i am astounded over your huge speed difference.
I think there is one part you didn't look at: tires. Those 27.5 mtb wheels had downhill tires. The 20 inch wheel also had rough tires. El alto has more like xc mtb tires, these have less rolling resistance. Should have used similar tires on El alto as well, or other wheels with more xc type tires to match El Alto.
Fun experiment though!
You see this sort of miss-matching wheels in a lot of recumbents, though they have their frames made so that the body position is ergonomic and aerodynamic.
Maybe not only the wheels make a difference when going uphill but also the groupset. If you switch from the Shimano Dura Ace groupset to the Shimano Viagra groupset, you might go upwards quite faster - and longer.
Interesting! Now please do a comparison between riding this and riding the same climb indoor with Kickr Move but _without_ Kickr Climb. Because this looks a lot like climbing usually feels while riding indoors.
When I clicked I was expecting to see some sub 5 kg carbon bike you borrowed from someone at the Hill Climb champs'. I was not expecting THAT 😮.
p.s. Conor will be receiving the cleaning bill to get the mouth full of coffee I spat across my living room out of the carpet.🤣
I'd like to see the outtakes of Connor doing a stopping distance challenge going downhill on the different wheel sizes!!!
Fascinating outcome. However, I do feel that this needs further investigation, such as Connor repeating the experiment on different bikes. Would a 700c rear wheel match with a narrow small front wheel? What about an adjustable fork, like a variable travel suspension fork to change the head angle when going into the climb? Maybe get your tame hill climber to check this one out too to see if it has an impact on his times too? Would a lab based climbing rig be suitable to test this? Great work Connor and GCN, just don't let the UCI seeing you playing like this, they might have a sulk! 🤣
Loved this video! I'm not sure I'll try this, but 10/10 for entertainment value. 😁
My Chris Dekerf 36er has the exact same rims!
i think you were faster because the 20 inch wheel was just lighter maybe? awesome video tho!!! it seemed so funny to ride on flats but climbing uphill 😂
Riders have been using setups similar to this at the Mt Washington Hillclimb for decades.
to optimize it, you'd probably want to switch both fork and wheel to get your axles level. you'd end up with a larger wheel to get the same axle angle as you'd lose the height from empty fork space.
Would be interesting to see something like this replicated on Zwift on a KickR Bike or climb set up. Same climb, one with the gradient switched on, then again with it off. Same principle surely. Position on the bike making it easier to generate power in your favoured and regular position.
Obviously nothing like real world, but curious to see now,
I hope Conor put that 20" wheel back on his son's bike when he was done with it!
You should see his sons bike right now! Now that is a tall front end 😂
Have Conner do a video comparing the Endurace vs Ultimate vs Aeroad (climb vs flat). Should be interesting to see how the Endurace competes against the race bikes
For MTB there was the Fox Talas fork; you could drop the front by about one inch on climbs.
8 inches of drop for this test
Excellent experiment ! But now surely we need to see you try the reverse, descending down cheddar gorge with 36” on the front and 20” on the back 🤔
if you spun the fork around backwards, it might give back some trail that you lose from having such a steep head tube angle when you drop the front end. I'm not sure if the brakes would work well turning backwards, and you would be further shortening the wheelbase, but it would probably feel a lot less twitchy.
That felt like a crossover episode, GCN + MythBusters! :)
With the small front wheel, now its perfect for Hank to do some crazy thing!
oh gosh, now I'm nervous haha
Adapt a Wahoo kicker so you can adjust the tilt on the road.....job done
Amazing results!
Try again with a 20" wheel and tire with a road tread rather than a knobby. Excellent video!
We need dropper forks. Like suspension forks, but you should be able to drop it for a climb.
pair it with a rear end that raises up to keep your bb off the ground
maybe have an telescopic air-ride fork in the front so you can adjust it level when running the flats or downhill....
My hope is for a day when bikes are custom built for each rider in a cost effective way, and that would include the availability of numerous wheel sizes to give everyone more or less the same range of frame angles. Custom built bikes aren't terribly expensive even today, especially when compared to off-the-shelf high end racing bikes, so the only thing missing is ease of wheel and tire selection. It shouldn't be so much harder to fit someone who is 5' tall relative to someone 6' tall when they are proportionally identical to each other.
I think the Feather has to be involved, perhaps a climb he has the KOM on and a slightly more refined bike 700c with a slick 20" out the front 🤔. All in the name of science of course.
Absolutely Brilliant!
With the British hill climb champs just behind us, it would be interesting for Andrew Feather/GCN to experiment with a 650b wheel on the front (seeing as he's switched over disc brakes) to see if the mixed wheel thing has an effect.
Looking good. This Farty Phenning... Kinda enjoys the very scientific approach. As opposed to Blakes Reverse Mullet video over at GMBN, which seem to be more of a fun experiment :)
this kind of video is what makes GCN channel big like it is now, we miss the old videos something like this.
I have thought about experimenting with different size wheels but then I remember that time I drove through Texas with all the lifted trucks I could hardly see around
This is quality content XD
Very interesting, funny 😂 and educational. It would be interesting to discover how it fairs on the flats and downhills to give the complete picture. It could an option to change for the pros to change to a smaller front wheel for a uphill section. 😃
The tire choice for this experiment is is curious to me. Wouldn't those nobby/hybrid tires hurt efficiency on smooth terrain and thus hurt your time?
It’s amazing how normal Connor makes this bike look.
Looking forward to Andrew Feather taking this on board for the future!
Nice video Conor. Next give the bike to Andrew Feathers to ride it.
Would like to see Andrew Feathers riding this bike and a Fixie, as a uphill challenge.
Is it allowed to have a mixed wheel sizes on the hill climb event?
Should use a backwards setback seatpost and longer stem to have rider weight more directly over the cranks