@gcn thank you for your prompt response. I feel my Sram bottom bracket has too much residence. Had a bike machine look into this and they advised me this is a common theme yet an upgrade of a new bottom bracket, and very much like GCN have pointed out to upgrade my tyres to Pirelli P Zero TLR tyres would make for a more enjoyable ride. Currently tiding a Orbea Orca team much like Hanks previous bike, and I'm impressed with the quality from Orbea. Very interested in your thoughts regarding upgrades and the bottom bracket i.e. which brand to go for? Unless this is a future video to establish best bang for consumers monies which bottom bracket is best. Thanks in advance. Keep up the sterling work.
I'm 6'2" and have 175mm on my Siskiu T7 but constantly have pedal strikes. I am on the verge of buying 165mm cranks... What is more worth it, $47 for 170mm or shell out $120 for 165mm cranks on my MTB??! I'm staying at 175mm on my road bike for now
I was asking my wife if she thought crank length or technique was more important... She muttered something about girth.... I'm not sure we we on the same page.
We did an experiment with my wife's bikes. She is quite small (4'10") and her bike came standard with 165mm cranks (frame size X-Small.) She had really tight hip angles when riding, so I picked up a set of 155mm cranks. As a test, we had her ride a course on the indoor trainer with her stock cranks, then she rested while I swapped the cranks, and she rode the same course on the trainer. The second run had about 10% higher average power, with a lower perceived exertion and lower heart rate.
Excellent. I've done a lot of testing on myself and a few customers of mine. I'm 6'1" tall, and after trying sizes from 153 to 130, settled on 145 as having the broadest power curve from about 50 rpm to 100+. I can pedal as hard as I want without hurting my knees, and I discovered to my surprise that if I pedal faster than 68 rpm at any load level, on any length, my heart rate goes up. I do pedal in the 80's quite a bit, but I don't stay there. My wife is 5'2" and has had success on 120s, but it's hard to get a reading on efficiency due to arthritis.
At least this was on annindoor trainer with a power meter... still a bit short on data but far less pseudo then the GCN test - which was fun to watch but. Most people would be slower on their last run anyway...😂
I got a bike fit. Went from 170mm cranks to 165mm cranks and had my seat tube raised. Once I got used to it, the biggest change in my riding was I could ride longer at a reasonably fast pace and still making it back home without being completely gassed.
I was always on 170-175mm crankarm, until I ride my wife's bike and found out 165mm fits me better. Now my bike has 165mm crankset. For reference, I am 175cm 5'9.
@@playerforty4621 Feel better, less knee issues for me. As of performance, I didn't notice a power difference, but there is a cadence difference. I ride at higher cadence on shorter cranks.
I’m 175cm tall as well. Literally just had this experience at my bike fit 3 hours ago. Gosh the 165mm is so much more comfortable to ride! What a difference 5mm makes wow..
If 170mm is about right for him then most people should be using 140mm. At the very least, there should have been a disclaimer at the end mentioning that.
Same here, I am 185cm tall and am "supposed" to use 172-175mm cranks. Only 165mm will go on my bike, anything above that is silly unless you are racing a bike.
Same here I used 175 and 172.5 for 30+ years (I am 185 but with very long legs), now I got some additional all-purpose bike (kind of gravel with lights and mudgard) where I just didn't care and there was 165 mounted. I found out it feels lots more confortable than my trainig bikes. The only back side is accelerations on ascends and tt like. But I'm sitting more stable and less "shaky" and back pain occures more seldom.
165s on all my bikes. If you like to spin like me, small cranks are always better. And better knee/hip angles makes cranky old me happier. (~182cm here)
Just got some 165s after using 172.5 forever. I have also downsized my chainrings so it won't be a completely fair comparison. Will fit them in the next few days
I went from 172.5 to 165. Overall power didn't change at all, but it really helped my endurance and almost cured my back issues from having the more open hip angle. I can get more aero too.
I've got 172.5 on all my bikes although I'm only 5'7" / 171cm tall. I fancy trying 165 cranks - although it seems bonkers to me that 7.5mm will make that much difference
I've been on 172.5 for a long time. I bought a set of 165's 6 months ago or so for a cheap price. Recently I just played with my saddle height, very minor lowering makes my upper back, traps and hands more comfortable and I sit back on the saddle more properly with more comfort. But getting some hip and low back pain under load and a touch of left knee pain. I feel like this is due to the knee traveling slightly higher. First thought is I should try those cranks finally to reduce knee and hip angle.
@@DarenCI've previously switched from 170 to 165, then back to the 170 because my 165mm cranks broke. It makes a noticeable (but not necessarily huge) difference to how I pedal and I had to raise my bars back to where I had it back then.
@@DarenC 7.5mm doesn't sound much, but the difference in the circumference (ie the distance each foot travels for a single revolution is 47mm - near enough 5cm. If you're riding with a cadence of 85rpm that's 4.25m per minute less that you're having to push your foot around, so on a 5 hour ride each foot has travelled over 1.25km more on the longer crank. Your muscles have to power that, and that doesn't account for any of the other benefits of positioning, cDA, hip angle, breathing ....
More testing required, I think. Shorter crank arms combined with wider gear range may be the optimal solution for many riders. Also, test flat terrain course times vs hilly course times. I live and ride in the mountains of west Texas, and am an ancient cyclist at 69. My mind is always open to new recipes for going faster and further, with less stress on my old chassis and meat engine, so keep up the testing with more riders, please. Thanks for pushing the boundaries of what we think we know, keep on pedaling forward!😁
I’m a short guy (5’ 7”) and I just recently went form 170mm cranks to 165mm and it’s so much more comfortable. At the top of the pedal stroke I no longer feel jammed up, it was odd at first making smaller circles as you pedal, but you get used to it and I’m glad I swapped to a smaller size.
I'm 185cm but i have rather short legs. I recently switched to 170mm with a compact from a 175 with a 52-36 and this has changed my cycling I'm coming back from injury and already blasting lots of PR
I am 5' 7" with short legs, I had been on 175mm cranks. When seat was low had knee pain. When seat was high the glutes would tighten up. Changed to 165mm cranks. Solved my knee / glute issues. Ability to make short accelerations went down, but could go faster on longer hills requiring over 2 minutes of effort.
I went from 172.5 to 165 after double hip replacements, to open hips up - I’m 5ft 8 - it has made a world of difference to general comfort and to my endurance - I’d advise anyone with hip/knee replacements to look into this! 👍🏼
That's a great point! Smaller cranks can really help get rider comfortable when they have fit issues. Did you do any research before moving to short cranks?
I recently went to 155mm from 170mm due to knee pain. As was mentioned in the video; getting started, sprinting and going uphill sucks. The pros outweigh the cons for me but if the knee pain wasn't an issue I'd likely stick to 170mm (I'm 5'6")
Yes it does. I'm 6-feet, 183cm, and have switched from 172.5 to 165. Love it. Enjoy the higher cadence, pedalling through corners, better power and easier to be tucked in. I swapped my front rings too from 52|36 to 54|40 cause I did notice I was spinning almost too much on any slight down and just couldn't find the right gear, but it wasn't essential. However, just going shorter cranks with then a ridiculously small chainring, that's not gonna work. Would be curious to see how this would be with same chainring, shorter cranks. Better analysis.
I've switched from 172.5 to 165 and love it. My cadence now is 105-110 but I also switched chain ring from 50-34 to 48-32 and cassette to 11s 12-25. Now im riding much faster and much more efortless at the same time.
@@AVFTSCycling Yeah I know. it's weird. I guess spinning higher but with a 54 vs 52, I can spin easier at say 95 vs 100. Any fast speed above 45km/hr it's super helpful. I just find I can find more gears
@@F4DZ4 Nice! I kept my rear 12sp cassette to 11-30 jsut cause I don't have any significant elevation. But my cadence is also higher, not as high as usually 100+, but in the 90-95 but that's cause I switched to 54
I have ridden 175, 172.5, 170, and 165mm over 49 years. Conclusion: Shorter cranks on long rides result in less fatigue. Smaller circles, when riding at 60% for long periods, are just more efficient. I have gears, so 'leverage' is irrelevant. It could also be the hip flex thing; it's way more comfortable. I've been on 165s for 11 years and won't return. (5'11" with proportionally long legs )
I,m 71 years old and 5,8 in length and using 172,5 mm cranks, however I turned an inch shorter the last years. So now I.m at the limit of my reach on my bike, if I have to raise my saddle, with the use of shorter cranks, I,m afraid the reach will increase more than i can handle.
I bought a new bike recently. As part of the purchase I had a bike fit. The fitter recommended 165mm cranks to replace the standard 175mm. I have a replacement knee with reduced bend which impacts my hip. The shorter cranks were installed (at no extra cost) and they have been fantastic. I am now much more comfortable and by default faster on a bike. I have also changed the cranks to 165mm on my no 2 road bike. I needed to change the cranks on my turbo/zwift bike which is a 12 year old Trek Madone with 10 speed ultegra groupset , that wasn't quite so easy. 165mm cranks for this age of bike are rarer than hens teeth but after a while I found a second hand set. After 4 months of riding 165mm I can confidently say that I am very pleased with the change. I am 185cm tall and ride a 58cm Tarmac and Roubaix.
I’m 6’2”. Riding with a pedal to the floor kind of rider I found myself struggling at times. I had little problem keeping up on the flats but when accenting hills I got dropped like a rock. Changed to 180’s and felt more power and ultimately found a new over the top speed.
Connor's rant about the small cranks had me cracking with tears 😂 "I can't accelerate." "I feel like a gorilla." 🤣 But in all seriousness, I have switched to 165mm after 2 decades of riding 175/175.2mm, and noticed significantly less tensions in the pelvic area. For someone who has struggled with hip-flexors forever, shorter cranks can be a game-changer. When I switched from 172.5mm to 165mm, I felt like I went from being Cavendish to being Campenaerts. I can stay low, and aero, and still feel very relaxed and comfortable.
Yes, I have tried a few. I'm 1.6 m and 62 kg and have always ridden whatever the bike had installed. Most of my bikes have been 172.5. Recently, at the advice of the local shop, I tried 170, 165 and 160. I found the 165 the most comfortable and efficient feeling. I'm sticking with them.
I've always used 170 because that's what came on a bike of my size. I became accustomed to it and it feels pretty good. I bought a bike that had 172.5 and that felt a little cramped in the upstroke when I was in the drops. So, with that bike I swapped the cranks with 165 and those felt really good with a balance of power and acceleration, plus it opened up my hips and breathing a little better. With that said, I'll probably will just keep riding the 170 because it's too expensive to swap them all out to 165.
Studies show that when people swap to very short cranks they need time to adapt before power delivery returns to normal. Interestingly, once adapted to shorter cranks, it takes longer for power delivery to return to normal when going the other way.
I went the other way on that on-I’m 199cm tall with a 100cm inseam, and my bike fitter recommended ridiculous long cranks at 200mm. He said I could go longer still, but I was too nervous. I LOVE it. Feels like I used to have a rubber band around my ankles but I took it off and can finally take a full stride. Of course, I’m not in the slammed stem, TT position phase of my riding career, and I’m not switching between a zillion bikes. It’s basically my roadie with XL cranks and my commuter/gravel with 175mm (which feel like playthings now). I think the real message is that if you can, you should find cranks that feel right, instead of assuming whatever comes on the bike is “right.”
I swapped to a 165mm carbon crank from a stock 172.5 ultegra crank. Instantly can breathe better in the drops, also I can drop the front and raise the saddle more, which make the bike looks better, or more “pro” if you prefer. So even just for the look of the bike, I think it’s worth it😂
Look at the other extreme GCN video with Dr. Emma Pooley for an interesting comparison. Shorter cranks and 650b wheels favor the shorter rider enabling them to breathe easier by opening up the hip angle. This gives them a distinct advantage on the climbs. Emma went on to win the Taiwan KOM. Amazing presenter and cyclist,
Currently use 150mm cranks 5'7" (170cm) and feel incredible on the bike. I just wish down to that size would be available from the big manufacturers so I dont have to go to some small brand's proprietary system :( Taller guys should be using longer cranks, which, standard crank lengths were always designed for taller riders. Shorter riders have been suffering with crank length unfortunately, so what is short to the average cyclist, say, 165mm, is long for me, and 150-155mm feels normal sized. Also, depending on how much shorter you go, there will be a adaptation period to get used to it. I don't think Connor ever had an issue with crank length because he is already tall and current crank length sizes have the same effect of pedaling as me with 150mm cranks.
Which 150mm cranks did you get ? The ones that I have been looking at and a somewhat plug and play one is the rotor aldhu crankset. I am currently looking for a shorter crank and would really like to keep my bb as is to avoid the hassles.
@@Mikejo3 one of my bikes has rotor’s aldhu, my time trial bike has 5DEV downhill mtb bike cranks (I shit you not when I say this lol) because they are sram 8-bolt cranks. Are they heavy, a bit, but I’d rather have it on that bike than the road one. I’ve been bitching to sram once a month to make down to 150mm so that I don’t have to go to third parties on crankset because I don’t want a niche proprietary system. Unfortunately it’s a bit of a waiting game for us.
I’m 6’2 and have battled knee pain. Years ago, I switched from 172.5 to 165. Will never go back. Eliminated dead spot at top of stroke, opened up hip angle and reduced knee pain.
Your comment highlights the shortcomings of this video; Connor just seems dismissive about the whole thing and clearly he was riding with too low of a saddle. Overall there was no insight gained from this video.
I had to switch to shorter cranks after knee replacement surgery which limited how far I could comfortably bend my knee. I got an adapter to put on the crank on the road bike I use on my smart trainer which let me try out different lengths from 170 to 135mm. I settled on 145mm as being the most comfortable (I’m short at 165cm). So I got a new bottom bracket, 30mm spindle and 145mm cranks from Appleman in Minneapolis and installed them on my outdoor road bike. And I’m now back to zooming around! I don’t feel like I’ve lost any power because I have lots of gears in the rear cassette. 😊
@@musclelessfitness2045 About 28" on the left, 29" on the right. I was in a car accident 45 years ago and busted my femur in half which was fixed with a titanium rod, which is still there.
@@belowthehill Thx. It's interesting that you settled for 145mm. You probably had to raise you saddle too high. What about the other lengths under 165cm? I thought maybe 150 or 155 would be fine, specially if you add shoes.
This comes from eMTB and downhill MTB riding, where running a shorter crank equates to fewer pedal strikes on roots and rocks. On an eMTB, the torque from the motor more or less fills the leverage gap that Connor mentions on the shortest crank. It makes sense that there’s an optimal crankset length for people’s different leg lengths, and that a crank can be too long or too short for a rider. I’m 6ft 1in with a 32in inside leg, but there’s guys out there of the same height with 33 - 36in, and common sense dictates that we should all probably have different crank lengths.
The greatest thing about this video was watching Connor on tiny cranks - it was like watching a toddler wearing her mother's giant high heels clomping along as quickly as possible.
@@edwarding4355 it was said that they had to every time although the may not have raised as much as they should have on the last one as they were running out of seat post
Yeah, get the tallest GCN guy to try the shortest cranks. That’s ridiculous. How about getting someone of an average 175 to 180 height. That’s more realistic for the the rest of the world. Someone with an 750 to 800 inseam length. (At least for men) Women riders will probably have shorter inseams.
@@shankeong6753 lol right? they obviously are very knowledgable and passionate about cycling but some videos are just not executed properly, for example, the fixed gear commuter video that was released recently. No foot retention with the fixed gear?!
Actually, women have longer inseam for same height. So adjusted for height difference the inseam would be similar. Also you give numbers more in 165-175 height range. But main thing, there is a legit research approach to look at the extreme cases first before diving into finer analysis. So tall person + short cranks is ok. I'd add Manon with 185 cranks, though, for a complete picture. But 5Dev don't make such to sponsor this experiment
@@DopeEd there are massive numbers of hipsters riding fixed gear bikes with flat pedals without complaint...possibly due to brain damage from not wearing helmets but that's reality.
As a 5'2" rider, I am already planning to go for much shorter cranks the next time I have to spec a new set! I'm looking forward to having a more ergonomically friendly and efficient setup for my size. The box jump analogy is a striking one-if everyone is made to use the same 2-foot box for their box jump fitness tests, I'm automatically at a disadvantage because I have to use a lot more energy to jump proportionally higher.
As another tall guy (2.05m) I've tried everything from 170-200mm. Longer cranks help when climbing as it's a constant acceleration force against gravity, much like your starting efforts. Have settled on 190s for the climbing bike and 175 on the flat/crit/tt bike.
Yeah, the average European Male is 180cm, so riding 'typical' cranks of 175mm is a scaling factor of 1:1.03. They're talking about a typical person going down to 165mm cranks (1:1.09) or 155mm cranks (1:1.16). If you use the exact same scaling factors for a 200cm man, then you're looking at the same 'size' cranks would actually be: - 175mm ==> 195mm - 165mm ==> 183mm - 155mm ==> 172mm So the 200cm host riding 170-175mm cranks is already riding his cranks at the small end of the spectrum. and him riding 155mm cranks is like a normal person riding 140mm cranks.
@@ivankrsnik9640 You find it hard to believe that a former pro who's ridden thousands of kilometres in competition doesn't know anything about bike fit and power delivery and isn't able to discern differences in his bike position? I can feel the difference between 172.5mm and 170mm at the top of the pedal stroke, and I'm just a recreational cyclist. So I'd expect an ex-pro to be able to detect a 5mm difference immediately.
I've got 190mm on my current bike, and like them a lot. I'm a bit shorter at 194cm but have long legs for my height. I noticed that the muscle just behind my knee at the outside of my leg (vastus lateralis?) would feel a lot more work than I was used to when I first tried them. It wasn't a problem, but that part of my leg would get tired first on a hard effort. I'm not sure if it's due to crank length, or wider Q, but either way, it caught up with the rest of my leg over a couple months of riding, and now if feels like I can make more power, and it's easier on my knees. Range of motion was never limiting me, so more range with less force is a good tradeoff to get the same power.
On my unicycle I have experimented a lot with crank-length. The nice thing about that is that it is a direct drive. One thing that is important, and which you didn´t mention in your video, is that with shorter cranks you have to raise your saddle. When racing with the unicycle I even went as small as 125mm. This is difficult to start, but when cycling it is really smooth. Fast stopping is difficult though, because of the small torque. The sweet spot for me on the unicycle is 155mm, while I use 170mm when unicycling in the woods, where you sometimes need high torque. The funny thing is that I never experimented with crank-length on any of my normal bikes. You inspired me to do that. My feeling is that 165mm is my sweet spot there.
With the unicycle you're almost always riding very sub-optimal cranks, because you need to compensate for being 1:1 gearing, often with a tiny wheel. I'm a tall guy with long legs, and I ride 110mm on my 20" freestyle, and 700c wheels (need stupid fast cadence to get anywhere), and 160mm on my mountain unicycle (24" downhill tire). I don't actually like the short cranks on any of them, it's simply that longer cranks wouldn't work. I don't think I'd use that as any indication of what's going to be best on a bike, though. I have 190mm on my bike, and love them. If my bicycle was stuck in its lowest gear with no option to fix it, I might want 110mm there, too, but with proper gearing, I can use the length that works best with my legs.
I've been thinking about this forever. I'm 195cm tall, and have always ridden 175 cranks, but I feel like it's impossible to put power down properly in the upstroke (when I try to go aero, that is). I can do it for a short time, but never longer than 2-3 minutes at a time. I feel like shorter cranks could help, but just going to 172.5 seems too small of a change to have any effect and going much further than that seems scary. I mean, mostly scared about wasting the money (I have power meter cranks, so added cost there too).
If you ride fixed gear, installing shorter cranks is immediately noticeable as you are more connected to the bike. The shorter cranks feel more comfortable and you can spin them up faster. I started with 170mm and a 48t chainring. It was tough to get up to speed and also stopping. Once I changed to 165mm and 44t chainring the bike came alive.
@@samj1185 same with the halfbike I ride. It has really short cranks 145 or 150 but with a larger chainring than what is demonstrated on this video. My micro Pedalflow also has short crank arms with an extremely large chainring.
Yes, I have experimented with shorter cranks multiple times - simply because I use 180 mm cranks and they have been difficult to get decades ago and are almost impossible to get now. But when ever I rode bikes with shorter cranks (170 mm, 172.5 mm and 175 mm) it felt unnatural and very uncomfortable for me. So I sticked to 180 mm on all my bikes (even the TT) and I am very fine with them! …and btw, it was not easy to get them fit to the newer bikes and chain rings - but it was absolutely worth the effort and the money
Well, I’ve gone 172.5 to 175 (5’11 and 35 inch inseam). Sustained power is higher, and long climbs are faster. I do struggle to hold a sprint for as long though. But, other than CX racing, my racing days are over - so a sprint is less important. I do use 170s on the TT bike though.
All of my bikes have had 172.5mm cranks. I bought a groupset in the sale because it was too good a price not to have. They only had 170mm cranks left, so I thought it can't make that much difference. How wrong was I. Bloody brilliant.
I wentr to 165mm cranck with my gravel bike (i usually use 172?5 or 175mm cranck). 165 felt weird, i wouldn't feel any power in my legs but could spin super fast. It was also more confortable in term of hip and knee angle. I'm now using 170mm cranck and feel it's the best for me
@@gcn I was mostly riding to commute or bikepack so wasn’t interested in sprinting but still felt like i was missing on something when i was putting the power on the pedals. Maybe it’s just in my head 🤷🏻♂️
I've come to believe that crank length +/- 5mm has a lot to do with your personal cadence. if you prefer a slower cadence a longer crank will suit you better and vice vera if you prefer a faster cadence. I think it's like an engine, longer stroke= lower RPM, shorter stroke = higher RPM for same output at the wheels after passing through the appropriate gear ratios.
@@gcn definitely. I'm 190 cm tall and ride 175 cranks but also tried 180mm. However that made my cadence a fraction to low. I did like the acceleration out of corners. Then I tried Q-rings. That got my cadence up a little because the pedal goers trough the less loaded phase of the rotation faster. It really feels good. And I always wonder why that never comes up in debates about oval chainrings. Unfortunately I had to many dropped chains shifting to the inner chainring right when you don't want them. So it's back to the 175's with normal chainrings. Where I to build a TT-bike or other 1b setup I'd probably go back to 180's with q-rings.
I had my bike custom made and sent in my measurements and they catered the whole bike based on those figures. I never second questioned those decisions.
Cool video, I get the theory about shorter cranks. But it seems to optimize them you would have to lower the bottom bracket because raising your saddle is definitely an aerodynamic disadvantage. You also have to retrain yourself as far as gearing and cadence. Its all about smaller gearing and higher cadence and that is not something you learn on a short ride. 5DEV is a really cool company, but not all those cranks are Titanium. The one you showed with the triangles cut out is for sure aluminum, making it significantly more affordable then their Titanium offerings. Hopefully somebody has done the math to figure out what is the new optimum crank length for riders depending on their inseam.
Getting Conor to do the test is a great idea. It will bring out the feel of having too short a crank more easily and effectively than someone with short legs.
I designed a custom bike in 1982. A big project. I wish I could supply sources, and my papers, but it has been many decades and sources were lost. I measured my distance between joints (foot, leg, thigh, hips). The frame geometry was radical, as were some other elements of design. The end of the project was 165mm crank length (ideal was about 166.5mm) and to this day the best bike I have ever ridden. Climbed fast, the geometry said it would be a terror on descents, but was actually very well mannered. Compensation was also allowed for frame material (wall, diameter, geometry, tube length). Pedal platform height was also a factor to be considered when considering crank length.
It's crazy that Conor uses 175mm cranks while some S size bikes come with 170mm cranks. Cranks definitely need more variation in sizing. Hip impingement is a short person problem and the reason why is obvious.
When I was a kid in the 1980s I had a cheap Western Flyer BMX that came with 5.5" (139.7mm) cranks and a 36-tooth chain wheel. I never gave any thought to crank arm length or tooth count until the neighbor kid got a real BMX; a Diamond Back. He let me try it out and it was amazing; I loved it. It had 175mm crank arms and a 44-tooth chain wheel, and even though I was only 11 or 12 years old at the time and only about 5 feet tall, it still felt way better. I'm 6' 2" now and I have 180mm crank arms and 44/16 gearing on my BMXs. That setup has long been popular for BMXs (the racing oriented ones anyway); there were even some that came stock from the factory that way, like a 1980s Mongoose Pro Class for example.
I'm 175cm and went from 172.5 (stock) to 155. Took a handful of rides to get settled in, as it felt like I was riding a children's bike. But once I got used to them, I never looked back. Less knee pain, can spin faster, and more comfort since my seatpost is pulled out further.
I was on 155s some years ago and never had problems with my hips, though my fit was lacking in other departments. Then the crankset somehow melded with the chainrings and powermeter, so I chugged it. For whatever reason, I then got back on 172.5s. Now I'm on back on 160s after a break from cycling, and not only does my hip feel great, but I get a lot less sore/fatigued despite having lost heaps of strength. I'm literally down from 35kph averages to 25kph haha...
I switched from 175 to 165 a couple months ago. I have adjusted to it. I still notice that I don't have all the easy turning cranks when climbing, but that probably just allowed me to 'coast' or more easily rest through sectors of each chain ring revolution
I have used 170 for a long time and I still do on some bikes. But on my main recumbent I always have 160. For reference I am 178cm tall. About 15 years ago I experimented with various length trying 175 and 153 (diy modification of cheap 175, just clamp them in a milling machine, allign everything and drill a new thread 22mm away from the original one). The conclusion was that 153 might be limiting me a bit. Something like mentioned in this video: they felt like accelerating is too hard with them, like it is difficult to spin up the rpm enough to feel comfortable to change to the next gear. But when cruising they were comfortable mainly for my knees that did not like the 175 at all and even 170 was taxing them a little. So I decided that expensive 160mm cranks could be worth it (no cheap 160 available to try) and bought them. I never went back. For me personally I would also say that 160 on a recumbent feel similar to me as 170 do on an upright bike. Maybe how much your hips normally move when pedaling or something similar is a factor in that. I have always found it baffling that there are several frame sizes of every (upright) bike and when someone comes into a shop to buy a bike they will get lots of advice on what size would be right for them. But then a person 150cm tall will get told to use 170mm cranks same as someone 170cm tall and a person 2m tall would get 175mm cranks recommended same as someone 175cm tall. I would very much like to see more crank sizes generally available so that we could all chose what feels best for our individual case.
I’m using the 170s that came with my bike. I haven’t had any pain issues, I’m comfortable, and my bike fitter didn’t feel the need to change, so I’ll likely keep using what’s working
I’ve recently switched from 170s to 145s as an experiment and it’s been a revelation! I’ve been able to drop my bars by over 90mm with the same hip angle.
what a weird statement… since you’re the driving force of the race bike, you need to be comfortable… only then it’s fast over a period of time… you seem to only sprint to the next cafe to make same bold claims
@@antonkruger5652 my speed is about the same, I’ll probably a bit slower on the climbs until my body adapts but I’m definitely already a touch faster on the flat and downhill.
I'm 6'6" and used to 170mm cranks on an old 7-speed cassette mounted to Mavic rims driving a Columbus Nivachrome custom frame. Needed a second bike, so chose a 1985 vintage 'Frankenbike,' the owner modding all the running gear, which included 180mm cranks. It took a few rides to get used to, but setting the seat a bit higher to accommodate the extra 10mm radius at both extremes (knee to chest a bit higher and foot extended lower) and I was pleasantly surprised. Where the 180's excelled was with quick attacks on hills without changing gears, and using a smaller cog and lower cadence on the flats with higher speeds achieved without furious pedaling. Fast cadence accomplishes the same thing, but I felt more control over deliberate long muscle activation for more or less power with the longer stroke. That control over pressure into the pedal with the longer, higher torque crank was almost like changing gears, without changing gears.
I’ve had a dodgy knee (OA) for a few years now. Knee got progressively more painful. Went from 170mm (I’m 169cm) to 165 for a couple of years. Great but still got pain on long hilly rides. Went to 155cm Canfield cranks (more affordable than others) Jan this year for long bike packing trip on Epic HT - no pain, better comfort, less back pain 👍. Got another set for my Crux for gravel and CX - perfect!! They def work for me so thumbs up for shorter cranks! 👍 Y
One factor on crank length not taken into account here is saddle position. Horizontal placement won’t change rotation, but it will change the rise, and position of the joint. I understand we are now beginning to split very fine hairs. I was fortunate that the math, and comfort aligned. The true test is comfort, and efficiency over a very long test period. One thing I did observe was saddle position. I saw a photo of Graeme Obree during a sprint. He was using the very front of his saddle. This is a whole new world to explore.
cane creek's eewings for road have a minimum of 170mm crank length. It is smart for 5dev to promote short crank arms. And it is valid too. for old riders, a light single speed with short cranks can be very fast
All my bikes had 172.5 cranks. I bought a secondhand Ultegra group set with 170mm cranks. It did make a difference. I eventually wore the chainrings out and it was cheaper to buy a nearly new 12 speed 105 chainset from eBay than the compatible chainrings for my old group set. The only thing was, my bargain chainset had 172.5 cranks. I did notice a slight difference going back up a length, but I feel I’m riding like I used to do. More out of the saddle as it feels better to me with longer cranks. I reckon it depends on how you ride. The thing that interested me was my eBay purchase turned up in a box marked 165mm. I think my bargain buy was simply down to the seller swapping to shorter cranks….
I’m 6’5. I’ve gone from 175’s to 165’s and I’m really enjoying it. My hip angle is so much more open, big days don’t feel as brutal and my pelvis is rock solid. The range of movement is lower so I feel like my force production from the glute is more potent and my hip flexors are more engaged. All round win.
I think a lot depends on body size - more importantly thing length. Shorter thigh bone= shorter crank. Having said that, I always rode 170 on the road and 165 on the track. I found the extra leverage could help me over a bump on the road and the shorter crank would allow me to rev higher wit hteh fixed gear if the bunch really got moving on the track.
5'7" have 165mm on one bike and 170mm on the two others. Tried 165mm from all the bike-fitting talk, to be honest, can't tell any difference. But definitely feel more secure cornering and maybe less rock strikes (on gravel bike).
I'm about to switch to 165mm from 172.5mm. I messed around with crank lengths 30-years ago at Uni, and found no higher energy cost or savings for different lengths, but this change has been forced by a bad accident last year. I already had a big leg length discrepancy, but after smashing up my pelvis, and with an arthritic knee, I just ache too much on the bike. So far, it feels much better on my Kickr Bike - test will come when I get out in the real world.
I only ride recumbents and 150 mm is the biggest cranks I ride. Love the 140 mm´s. For me the best fit and I would never go back. It definitly takes time to get used to them though. By the way I´m 190 cm.
Gone were the days that they made videos without sponsored elements, in totally hilarious Top Gear style of rubbish bikes challenges. The message is not in the crank length, it's just to showcase 5dev.
Okay, we have first impressions from Connor for each crank length - that's great. But the question "which crank is was fastest?" in the end is weird - just based on the presented results, one might conclude "longer = faster", slap on 175mm cranks and then face bike fit (i.e. comfort/sustainability) consequences of this change. Neill Stanbury's summary on this topic is far more reasonable, which, in short is: if comfort is your priority = shorter cranks, if doing kind of rides where instantaneous power is important (e.g. crit racing) = longer cranks.
If you are mashing uphill standing longer is faster. If you are spinning 150 rpm in an easier gear you will be able to hold it longer on shorter. 170mm cranks put about 9% more pressure on your knee than 165mm cranks.
When I had the Biopace chainring I loved it. They may not be appropriate for racing, but I think they may have a place for casual riders as well as ultra-distance racing. I’d enjoy seeing them tested.
I went from 175 to 160's to see if they would help knee pain I was having. These things were a game changer for me. I can pedal without knee pain now! They might not be for everybody. But, I think a lot of people would benefit from trying.
Due to an accident in February 2018, I (177cm and 85.3cm inseam) catched a cartilage damage in my left knee (I got hit by a car as a pedestrian - the real dangers are where you expect them the least), and therefore tried shorter cranks than my since 1995 used 175mm, and tried 172,5mm. Although I even adjusted the saddle height (+2.5mm), the cranks respectively the pedalling felt uncomfortable, with added pressure in the "wounded" knee, so I switched back to 175mm. On the other hand, years before I also tried 177.5mm (as I ride Campy square taper since 2006, switching was not that difficult), but after about 30 minutes, my legs got heavy, and I felt I was losing power, so for me 175mm seem to be the sweet spot.
What a coincidence, I've been catching up on all the videos others have done on this topic and decided to swap to 152mm cranks (I'm 172 cm). The bike manufacturers try to simplify their inventory when building the different sizes, so I can see how they ignore this part of bike sizing, since it also helps their bottom line. Many cyclists who focus on performance are young & fit, so can adapt to less-than-ideal crank lengths without problem. But I'm getting older and having knee issues after long distance rides. So this is what motivated me to switch. I found a cheap set of cranks online, mostly fit square tapered spindles, which are slightly older design, but I also have cheaper (not the latest cutting-edge & expensive tech) bikes, so it's quite economical for me to switch to shorter cranks. Many short cranks are made for ebikes these days, which don't need the longer torque leverage anyway.
High cadence is *key* for maintaining power with short cranks. If I raise my saddle *slightly less* than the change in crank length, I feel more comfortable at the high cadences needed to compensate for lack of torque. Allowing me to overcome knee issues after progressing from 135mm, the sweet spot for me (5'6") has been 153mm. Great pedal clearance at crit speeds, decent cda, and knee friendly.
Yes i have modified my crank from length from 170mm to 150mm, i am 5,2" in height.. it has worked me wonder i am able maintain high cadence with good power.. and comfort is really good ..able avoid hip injury.. but need at least month to get used to it ...climbs can be bit difficult initially, once get used to you are going to enjoy shorter crank.
I have gone from 172.5 and 175 stock length to 170s and comfort and speed have improved. My fixie build however is 165 to prevent pedal strikes even though I think 170s would help a little with stability out the saddle. As Conor found, tall riders will find that the shortest lengths take things too far but shorter riders would make 155s work very well. The sweet spot is dependent on your own biomechanics but often that is one size smaller than bike brands spec for a given size frame.
Far be it for me to be simplistic, but basic high school physics tells us that a longer arm is going to provide greater leverage, so it's obviously going to provide more torque. But just like with cars, you can either have torque, or you can have power; but not BOTH. Increasing torque sacrifices power, while increasing power costs torque. Crank arm lengths have stayed the same because they represent the "happy medium" between torque and power (for average riders). For extreme race conditions, a shorter arm might be useful (like on a velodrome) because torque won't be needed to climb hills. Contrarily, a longer arm would be more useful on steep climbs. I run 175mm on both my MTB and my road bike, because I'm 6'2" and I live where the terrain is very hilly. I need the torque for the ascents and the power for the descents.
I wonder if the super short cranks could help folks with some mobility impingements, or who may otherwise use the elliptical bikes - but would rather have a seated position.
I'm 6'8 and use 200 mm cranks. When I ride 170's they feel ridiculous. The downside is my bike frame needs to be designed for longer cranks (KHS 747 - Zinn)
I rode 152'5mm cranks for some time, years ago. There was no discernable power loss and I kind of liked them. But having a shorter crank requires having a lower BB, because otherwise I needed to raise the saddle. I run 180s now.
@@gcn But it raises the COG of the bike - making it sluggish. That and rising the saddle requires rising the bars - which may prove to be quite expensive. Overall - shorter cranks require a frame designed around them.
After having a Total knee replacement in right leg I couldn't cycle for a year or so due to pain and basically the knee didn't bend sufficiently to even turn the crank, very painful and on the odd day that I could cycle I found my right knee almost hitting my chest. After a lot of experimenting I eventually went from a 172mm Right Hand crank down to 125mm (the left hand crank is still 172mm). I can get on bike and pedal straight away, no pain...did this with all my bikes (had an engineering company reduce the length and drill new threaded holes for pedals. It looks odd but it works and gets me out on the bike.
I had a knee replacement and moved to 155 cranks to make it easier to get over the top of the pedal stroke. Defiantly a bit slower especially up hill than the 165 I was using but better for my knee. I’m 5’10” with short 30” inside leg
I had the opportunity to try different lengths during a bike fit and ended up with 170 instead of 175 that came with the bike. 165 felt like a kids bike which might be due to my long legs. Would be worth an investigation why most bikes still come with too long cranks and too wide bars.
Biopace is what I’m familiar with, I used it for years. It worked great other than if you wanted to sprint. I once had the back wheel start bouncing as I started up a steep hill out of the saddle.
Everyone has an optimal crank length; depends on what kind of rider you are and the type of riding you're doing. My biggest challenge was loss of leverage going to 170mm cranks I had to increase my cadence overall, so weighing pros and cons of shorter cranks they are beneficial for me. The biggest thing I noticed is how much better my legs felt after my ride. I have to think about longevity nowadays
I used to have 170 cranks on all of my recumbents. I had no idea there were shorter crank sizes. My first velomobile came with 155 cranks. I didn’t notice any difference with the shorter cranks. Last fall I had a conversation with a velomobile designer about crank length. He suggested I try 140mm cranks because he had found he actually was faster with shorter cranks. I was shocked to find that my commute times did drop with 140mm cranks. Strangely enough, I actually accelerate and climb faster with the shorter cranks. I can spin more easily. I think my height (5’6”) and the recumbent position lend themselves to shorter cranks. I have some tall friends riding velomobile with as short as 130mm cranks and they actually find it comfortable and are still incredibly rapid riders.
I find you have a narrower power band with shorter cranks, I find myself changing gear more to stay at a certain cadence sweet spot. I think that is why mtbs come with 175mm cranks because of such rapid speed and gradient changes. It's similar to the difference between a 2 and 4 stroke dirt bike.
I've found that as I've got older (46 now), my hips are loads tighter than they used to be, despite stretching etc etc. I went shorter to 155s and it's night and day the difference. Only took a handful of rides to get used to the feel.
the argument for shorter cranks makes sense especially when I heard it from a physical therapist. however if we shorten crank length how are we supposed to fit our saddles and general fit? is our leg supposed to be slightly bent? and if we go shorter on the crank our leg will be bent more than just slightly and then how do we organize the rest of the bike? doesn't this slight adjustment and change flip the whole thing upside down on its head? shorter cranks up the power and consistency we put down lowering fatigue. GREAT. but no one is talking about the rest of the equation.
Have you experimented with shorter crank length 👀
No, but I am considering upgrading my bottom bracket to a chris king. Currently running Sram Rival Etap 12 speed. What's your thoughts?
@@tonyBobb5209 Nothing wrong with a bit of Bling! Why do you want to upgrade?
Not yet, but I do want to as soon as possible
@gcn thank you for your prompt response. I feel my Sram bottom bracket has too much residence. Had a bike machine look into this and they advised me this is a common theme yet an upgrade of a new bottom bracket, and very much like GCN have pointed out to upgrade my tyres to Pirelli P Zero TLR tyres would make for a more enjoyable ride. Currently tiding a Orbea Orca team much like Hanks previous bike, and I'm impressed with the quality from Orbea.
Very interested in your thoughts regarding upgrades and the bottom bracket i.e. which brand to go for? Unless this is a future video to establish best bang for consumers monies which bottom bracket is best.
Thanks in advance.
Keep up the sterling work.
I'm 6'2" and have 175mm on my Siskiu T7 but constantly have pedal strikes. I am on the verge of buying 165mm cranks... What is more worth it, $47 for 170mm or shell out $120 for 165mm cranks on my MTB??! I'm staying at 175mm on my road bike for now
I was asking my wife if she thought crank length or technique was more important... She muttered something about girth.... I'm not sure we we on the same page.
Check the video
😅😅😅
She prefers a big chainring?
That's funny, she was telling me the opposite a couple of days ago... 😁
girth matters, it improves stiffness
We did an experiment with my wife's bikes. She is quite small (4'10") and her bike came standard with 165mm cranks (frame size X-Small.) She had really tight hip angles when riding, so I picked up a set of 155mm cranks. As a test, we had her ride a course on the indoor trainer with her stock cranks, then she rested while I swapped the cranks, and she rode the same course on the trainer. The second run had about 10% higher average power, with a lower perceived exertion and lower heart rate.
10% is a lot!
Excellent. I've done a lot of testing on myself and a few customers of mine. I'm 6'1" tall, and after trying sizes from 153 to 130, settled on 145 as having the broadest power curve from about 50 rpm to 100+. I can pedal as hard as I want without hurting my knees, and I discovered to my surprise that if I pedal faster than 68 rpm at any load level, on any length, my heart rate goes up. I do pedal in the 80's quite a bit, but I don't stay there. My wife is 5'2" and has had success on 120s, but it's hard to get a reading on efficiency due to arthritis.
Maybe she'd just warmed up properly? 10% is a lot.
@@Ugoeh2my i know your inseam?
At least this was on annindoor trainer with a power meter... still a bit short on data but far less pseudo then the GCN test - which was fun to watch but. Most people would be slower on their last run anyway...😂
I got a bike fit. Went from 170mm cranks to 165mm cranks and had my seat tube raised. Once I got used to it, the biggest change in my riding was I could ride longer at a reasonably fast pace and still making it back home without being completely gassed.
That's awesome! 🙌Great to hear you've found a system that works for you
How tall are you sir? If I may know..
and how tall would you be ?? I'm going this same route awaiting my new chainrings and crankset. I'm 5"6".
@@g.fortin3228 I'm 5'6" .
I was always on 170-175mm crankarm, until I ride my wife's bike and found out 165mm fits me better. Now my bike has 165mm crankset. For reference, I am 175cm 5'9.
Interesting! Living proof that you can't nock it until you've tried it 👀
Feeling better or performing better? Sounds like this would be better applied on really steep hills or MTB
@@playerforty4621 Feel better, less knee issues for me. As of performance, I didn't notice a power difference, but there is a cadence difference. I ride at higher cadence on shorter cranks.
I’m 175cm tall as well. Literally just had this experience at my bike fit 3 hours ago. Gosh the 165mm is so much more comfortable to ride! What a difference 5mm makes wow..
Exactly the same for me. 5’9” - 165 mm cranks. 30” inseam.
You got a 7 foot guy to test short crank lengths?
😁😁😁😁😁
He looks like a giraffe to me , but I'm 5'-5"
You shouldn't be sitting so close to the monitor@@timc7312
If 170mm is about right for him then most people should be using 140mm.
At the very least, there should have been a disclaimer at the end mentioning that.
I run 95mm im 5 10 . Anything over a 100mm doesn't feel right.
Went to 165.0mm after 20+ years on 172.5mm and will not look back. Much more comfortable and didn’t notice any performance degradation at all!
I bought a set of 165's cheap that has been sitting there for months. I think I need to switch them out soon and see how they feel.
Same here, I am 185cm tall and am "supposed" to use 172-175mm cranks. Only 165mm will go on my bike, anything above that is silly unless you are racing a bike.
Same here I used 175 and 172.5 for 30+ years (I am 185 but with very long legs), now I got some additional all-purpose bike (kind of gravel with lights and mudgard) where I just didn't care and there was 165 mounted. I found out it feels lots more confortable than my trainig bikes. The only back side is accelerations on ascends and tt like. But I'm sitting more stable and less "shaky" and back pain occures more seldom.
165s on all my bikes. If you like to spin like me, small cranks are always better. And better knee/hip angles makes cranky old me happier. (~182cm here)
Just got some 165s after using 172.5 forever. I have also downsized my chainrings so it won't be a completely fair comparison. Will fit them in the next few days
I went from 172.5 to 165. Overall power didn't change at all, but it really helped my endurance and almost cured my back issues from having the more open hip angle. I can get more aero too.
I've got 172.5 on all my bikes although I'm only 5'7" / 171cm tall. I fancy trying 165 cranks - although it seems bonkers to me that 7.5mm will make that much difference
I've been on 172.5 for a long time. I bought a set of 165's 6 months ago or so for a cheap price. Recently I just played with my saddle height, very minor lowering makes my upper back, traps and hands more comfortable and I sit back on the saddle more properly with more comfort. But getting some hip and low back pain under load and a touch of left knee pain. I feel like this is due to the knee traveling slightly higher. First thought is I should try those cranks finally to reduce knee and hip angle.
@@DarenCI've previously switched from 170 to 165, then back to the 170 because my 165mm cranks broke. It makes a noticeable (but not necessarily huge) difference to how I pedal and I had to raise my bars back to where I had it back then.
@@DarenC 7.5mm doesn't sound much, but the difference in the circumference (ie the distance each foot travels for a single revolution is 47mm - near enough 5cm. If you're riding with a cadence of 85rpm that's 4.25m per minute less that you're having to push your foot around, so on a 5 hour ride each foot has travelled over 1.25km more on the longer crank. Your muscles have to power that, and that doesn't account for any of the other benefits of positioning, cDA, hip angle, breathing ....
Yep, On a normal size bike he looks like he is on a kids nike
More testing required, I think. Shorter crank arms combined with wider gear range may be the optimal solution for many riders. Also, test flat terrain course times vs hilly course times.
I live and ride in the mountains of west Texas, and am an ancient cyclist at 69. My mind is always open to new recipes for going faster and further, with less stress on my old chassis and meat engine, so keep up the testing with more riders, please.
Thanks for pushing the boundaries of what we think we know, keep on pedaling forward!😁
We would love to do some more testing 🙌
I hear ‘ya. Old engine also, and I now seem to be blowing a lot of gas past the rings.
I’m a short guy (5’ 7”) and I just recently went form 170mm cranks to 165mm and it’s so much more comfortable. At the top of the pedal stroke I no longer feel jammed up, it was odd at first making smaller circles as you pedal, but you get used to it and I’m glad I swapped to a smaller size.
Awesome! It's one of those things that really can make a difference when make the switch 🙌 Are you 165mm for good now?
I’m the same size and switched to 165 and will always put them on my bikes. Comfort and speed, worth the swap.
I'm 185cm but i have rather short legs. I recently switched to 170mm with a compact from a 175 with a 52-36 and this has changed my cycling I'm coming back from injury and already blasting lots of PR
I am 5' 7" with short legs, I had been on 175mm cranks. When seat was low had knee pain. When seat was high the glutes would tighten up. Changed to 165mm cranks. Solved my knee / glute issues. Ability to make short accelerations went down, but could go faster on longer hills requiring over 2 minutes of effort.
165 should be your max length. 155 or 160 could also be ideal.
I went from 172.5 to 165 after double hip replacements, to open hips up - I’m 5ft 8 - it has made a world of difference to general comfort and to my endurance - I’d advise anyone with hip/knee replacements to look into this! 👍🏼
That's a great point! Smaller cranks can really help get rider comfortable when they have fit issues. Did you do any research before moving to short cranks?
I recently went to 155mm from 170mm due to knee pain. As was mentioned in the video; getting started, sprinting and going uphill sucks. The pros outweigh the cons for me but if the knee pain wasn't an issue I'd likely stick to 170mm (I'm 5'6")
May i know your inseam?
155mm cranks are too small
Yes it does. I'm 6-feet, 183cm, and have switched from 172.5 to 165. Love it. Enjoy the higher cadence, pedalling through corners, better power and easier to be tucked in. I swapped my front rings too from 52|36 to 54|40 cause I did notice I was spinning almost too much on any slight down and just couldn't find the right gear, but it wasn't essential. However, just going shorter cranks with then a ridiculously small chainring, that's not gonna work. Would be curious to see how this would be with same chainring, shorter cranks. Better analysis.
It's interesting you benefited from harder gearing, because shorter cranks increase cadence but also make gears harder at the same time
I've switched from 172.5 to 165 and love it.
My cadence now is 105-110 but I also switched chain ring from 50-34 to 48-32 and cassette to 11s 12-25.
Now im riding much faster and much more efortless at the same time.
@@AVFTSCycling could be that he's putting down better power due to the added comfort of the shorter cranks, but that's just a guess.
@@AVFTSCycling Yeah I know. it's weird. I guess spinning higher but with a 54 vs 52, I can spin easier at say 95 vs 100. Any fast speed above 45km/hr it's super helpful. I just find I can find more gears
@@F4DZ4 Nice! I kept my rear 12sp cassette to 11-30 jsut cause I don't have any significant elevation. But my cadence is also higher, not as high as usually 100+, but in the 90-95 but that's cause I switched to 54
I have ridden 175, 172.5, 170, and 165mm over 49 years. Conclusion: Shorter cranks on long rides result in less fatigue. Smaller circles, when riding at 60% for long periods, are just more efficient. I have gears, so 'leverage' is irrelevant. It could also be the hip flex thing; it's way more comfortable. I've been on 165s for 11 years and won't return. (5'11" with proportionally long legs )
Spot on. Same proportions and experience to you.
I,m 71 years old and 5,8 in length and using 172,5 mm cranks, however I turned an inch shorter the last years. So now I.m at the limit of my reach on my bike, if I have to raise my saddle, with the use of shorter cranks, I,m afraid the reach will increase more than i can handle.
@@peternijssen8708 raise the stem?
@@grantbeerling4396 my stem is at it’s limit and i do not prefer to use a stemextender.
I bought a new bike recently. As part of the purchase I had a bike fit. The fitter recommended 165mm cranks to replace the standard 175mm. I have a replacement knee with reduced bend which impacts my hip. The shorter cranks were installed (at no extra cost) and they have been fantastic. I am now much more comfortable and by default faster on a bike. I have also changed the cranks to 165mm on my no 2 road bike. I needed to change the cranks on my turbo/zwift bike which is a 12 year old Trek Madone with 10 speed ultegra groupset , that wasn't quite so easy. 165mm cranks for this age of bike are rarer than hens teeth but after a while I found a second hand set. After 4 months of riding 165mm I can confidently say that I am very pleased with the change. I am 185cm tall and ride a 58cm Tarmac and Roubaix.
I’m 6’2”. Riding with a pedal to the floor kind of rider I found myself struggling at times. I had little problem keeping up on the flats but when accenting hills I got dropped like a rock. Changed to 180’s and felt more power and ultimately found a new over the top speed.
Awesome! Great to hear that crank length changed your riding 🙌 Are you enjoying yourself more now too?
Connor's rant about the small cranks had me cracking with tears 😂
"I can't accelerate."
"I feel like a gorilla."
🤣
But in all seriousness, I have switched to 165mm after 2 decades of riding 175/175.2mm, and noticed significantly less tensions in the pelvic area. For someone who has struggled with hip-flexors forever, shorter cranks can be a game-changer. When I switched from 172.5mm to 165mm, I felt like I went from being Cavendish to being Campenaerts. I can stay low, and aero, and still feel very relaxed and comfortable.
That's awesome! Great to hear that you are loving shorter cranks, would you ever go back? 👀
Yes, I have tried a few. I'm 1.6 m and 62 kg and have always ridden whatever the bike had installed. Most of my bikes have been 172.5. Recently, at the advice of the local shop, I tried 170, 165 and 160. I found the 165 the most comfortable and efficient feeling. I'm sticking with them.
I've always used 170 because that's what came on a bike of my size. I became accustomed to it and it feels pretty good. I bought a bike that had 172.5 and that felt a little cramped in the upstroke when I was in the drops. So, with that bike I swapped the cranks with 165 and those felt really good with a balance of power and acceleration, plus it opened up my hips and breathing a little better. With that said, I'll probably will just keep riding the 170 because it's too expensive to swap them all out to 165.
Studies show that when people swap to very short cranks they need time to adapt before power delivery returns to normal. Interestingly, once adapted to shorter cranks, it takes longer for power delivery to return to normal when going the other way.
I'm 5'8" and been using 165mm cranks for 20yrs. just a few months back i switched to 170mm and whoa pedaling has never been easier 😊
I went the other way on that on-I’m 199cm tall with a 100cm inseam, and my bike fitter recommended ridiculous long cranks at 200mm. He said I could go longer still, but I was too nervous. I LOVE it. Feels like I used to have a rubber band around my ankles but I took it off and can finally take a full stride. Of course, I’m not in the slammed stem, TT position phase of my riding career, and I’m not switching between a zillion bikes. It’s basically my roadie with XL cranks and my commuter/gravel with 175mm (which feel like playthings now). I think the real message is that if you can, you should find cranks that feel right, instead of assuming whatever comes on the bike is “right.”
I swapped to a 165mm carbon crank from a stock 172.5 ultegra crank. Instantly can breathe better in the drops, also I can drop the front and raise the saddle more, which make the bike looks better, or more “pro” if you prefer. So even just for the look of the bike, I think it’s worth it😂
It's worth it for that pro look alone 😉
Look at the other extreme GCN video with Dr. Emma Pooley for an interesting comparison. Shorter cranks and 650b wheels favor the shorter rider enabling them to breathe easier by opening up the hip angle. This gives them a distinct advantage on the climbs. Emma went on to win the Taiwan KOM. Amazing presenter and cyclist,
It's really cool that we have the options now to change crank sizes 🙌
Currently use 150mm cranks 5'7" (170cm) and feel incredible on the bike. I just wish down to that size would be available from the big manufacturers so I dont have to go to some small brand's proprietary system :(
Taller guys should be using longer cranks, which, standard crank lengths were always designed for taller riders. Shorter riders have been suffering with crank length unfortunately, so what is short to the average cyclist, say, 165mm, is long for me, and 150-155mm feels normal sized.
Also, depending on how much shorter you go, there will be a adaptation period to get used to it. I don't think Connor ever had an issue with crank length because he is already tall and current crank length sizes have the same effect of pedaling as me with 150mm cranks.
Which 150mm cranks did you get ? The ones that I have been looking at and a somewhat plug and play one is the rotor aldhu crankset. I am currently looking for a shorter crank and would really like to keep my bb as is to avoid the hassles.
@@Mikejo3 one of my bikes has rotor’s aldhu, my time trial bike has 5DEV downhill mtb bike cranks (I shit you not when I say this lol) because they are sram 8-bolt cranks. Are they heavy, a bit, but I’d rather have it on that bike than the road one. I’ve been bitching to sram once a month to make down to 150mm so that I don’t have to go to third parties on crankset because I don’t want a niche proprietary system. Unfortunately it’s a bit of a waiting game for us.
@@atakddhi may i know your inseam?
I’m 6’2 and have battled knee pain. Years ago, I switched from 172.5 to 165. Will never go back. Eliminated dead spot at top of stroke, opened up hip angle and reduced knee pain.
Eliminating the Dead spot at the top of stroke by crank selection is really the KEY to this entire GCN topic.
Your comment highlights the shortcomings of this video; Connor just seems dismissive about the whole thing and clearly he was riding with too low of a saddle. Overall there was no insight gained from this video.
I had to switch to shorter cranks after knee replacement surgery which limited how far I could comfortably bend my knee. I got an adapter to put on the crank on the road bike I use on my smart trainer which let me try out different lengths from 170 to 135mm. I settled on 145mm as being the most comfortable (I’m short at 165cm). So I got a new bottom bracket, 30mm spindle and 145mm cranks from Appleman in Minneapolis and installed them on my outdoor road bike. And I’m now back to zooming around! I don’t feel like I’ve lost any power because I have lots of gears in the rear cassette. 😊
Can you tell me a brand name for that adapter?
What's your inseam?
@@musclelessfitness2045
About 28" on the left, 29" on the right. I was in a car accident 45 years ago and busted my femur in half which was fixed with a titanium rod, which is still there.
@@belowthehill Thx. It's interesting that you settled for 145mm. You probably had to raise you saddle too high.
What about the other lengths under 165cm? I thought maybe 150 or 155 would be fine, specially if you add shoes.
This comes from eMTB and downhill MTB riding, where running a shorter crank equates to fewer pedal strikes on roots and rocks. On an eMTB, the torque from the motor more or less fills the leverage gap that Connor mentions on the shortest crank.
It makes sense that there’s an optimal crankset length for people’s different leg lengths, and that a crank can be too long or too short for a rider. I’m 6ft 1in with a 32in inside leg, but there’s guys out there of the same height with 33 - 36in, and common sense dictates that we should all probably have different crank lengths.
The greatest thing about this video was watching Connor on tiny cranks - it was like watching a toddler wearing her mother's giant high heels clomping along as quickly as possible.
It looks odd. I don't think the mechanic raised the seat when the cranks were shortened
@@edwarding4355 it was said that they had to every time although the may not have raised as much as they should have on the last one as they were running out of seat post
Hahahaha it's a funny look right! 👀
Yeah, get the tallest GCN guy to try the shortest cranks. That’s ridiculous. How about getting someone of an average 175 to 180 height. That’s more realistic for the the rest of the world. Someone with an 750 to 800 inseam length. (At least for men) Women riders will probably have shorter inseams.
exactly the same i was thinking. GCN is getting stupid these days.
This is a great test vs short people who are expected to use short cranks
@@shankeong6753 lol right? they obviously are very knowledgable and passionate about cycling but some videos are just not executed properly, for example, the fixed gear commuter video that was released recently. No foot retention with the fixed gear?!
Actually, women have longer inseam for same height. So adjusted for height difference the inseam would be similar. Also you give numbers more in 165-175 height range.
But main thing, there is a legit research approach to look at the extreme cases first before diving into finer analysis. So tall person + short cranks is ok. I'd add Manon with 185 cranks, though, for a complete picture. But 5Dev don't make such to sponsor this experiment
@@DopeEd there are massive numbers of hipsters riding fixed gear bikes with flat pedals without complaint...possibly due to brain damage from not wearing helmets but that's reality.
As a 5'2" rider, I am already planning to go for much shorter cranks the next time I have to spec a new set! I'm looking forward to having a more ergonomically friendly and efficient setup for my size. The box jump analogy is a striking one-if everyone is made to use the same 2-foot box for their box jump fitness tests, I'm automatically at a disadvantage because I have to use a lot more energy to jump proportionally higher.
As another tall guy (2.05m) I've tried everything from 170-200mm. Longer cranks help when climbing as it's a constant acceleration force against gravity, much like your starting efforts.
Have settled on 190s for the climbing bike and 175 on the flat/crit/tt bike.
Yeah, the average European Male is 180cm, so riding 'typical' cranks of 175mm is a scaling factor of 1:1.03. They're talking about a typical person going down to 165mm cranks (1:1.09) or 155mm cranks (1:1.16).
If you use the exact same scaling factors for a 200cm man, then you're looking at the same 'size' cranks would actually be:
- 175mm ==> 195mm
- 165mm ==> 183mm
- 155mm ==> 172mm
So the 200cm host riding 170-175mm cranks is already riding his cranks at the small end of the spectrum. and him riding 155mm cranks is like a normal person riding 140mm cranks.
I think this needs more attention. The maths is important in this message.
i find it hard to believe that someone that tall with inseam more that 1m can notice crank length change of 5mm (Connons first test)
@@ivankrsnik9640 You find it hard to believe that a former pro who's ridden thousands of kilometres in competition doesn't know anything about bike fit and power delivery and isn't able to discern differences in his bike position? I can feel the difference between 172.5mm and 170mm at the top of the pedal stroke, and I'm just a recreational cyclist. So I'd expect an ex-pro to be able to detect a 5mm difference immediately.
I've got 190mm on my current bike, and like them a lot. I'm a bit shorter at 194cm but have long legs for my height.
I noticed that the muscle just behind my knee at the outside of my leg (vastus lateralis?) would feel a lot more work than I was used to when I first tried them. It wasn't a problem, but that part of my leg would get tired first on a hard effort. I'm not sure if it's due to crank length, or wider Q, but either way, it caught up with the rest of my leg over a couple months of riding, and now if feels like I can make more power, and it's easier on my knees. Range of motion was never limiting me, so more range with less force is a good tradeoff to get the same power.
On my unicycle I have experimented a lot with crank-length. The nice thing about that is that it is a direct drive. One thing that is important, and which you didn´t mention in your video, is that with shorter cranks you have to raise your saddle. When racing with the unicycle I even went as small as 125mm. This is difficult to start, but when cycling it is really smooth. Fast stopping is difficult though, because of the small torque. The sweet spot for me on the unicycle is 155mm, while I use 170mm when unicycling in the woods, where you sometimes need high torque. The funny thing is that I never experimented with crank-length on any of my normal bikes. You inspired me to do that. My feeling is that 165mm is my sweet spot there.
He did mention it: every time he shortened the cranks he said he had to raise his saddle.
@@Cyco-Dude thanks, don't know how I missed that.
With the unicycle you're almost always riding very sub-optimal cranks, because you need to compensate for being 1:1 gearing, often with a tiny wheel. I'm a tall guy with long legs, and I ride 110mm on my 20" freestyle, and 700c wheels (need stupid fast cadence to get anywhere), and 160mm on my mountain unicycle (24" downhill tire). I don't actually like the short cranks on any of them, it's simply that longer cranks wouldn't work.
I don't think I'd use that as any indication of what's going to be best on a bike, though. I have 190mm on my bike, and love them.
If my bicycle was stuck in its lowest gear with no option to fix it, I might want 110mm there, too, but with proper gearing, I can use the length that works best with my legs.
I've been thinking about this forever. I'm 195cm tall, and have always ridden 175 cranks, but I feel like it's impossible to put power down properly in the upstroke (when I try to go aero, that is). I can do it for a short time, but never longer than 2-3 minutes at a time. I feel like shorter cranks could help, but just going to 172.5 seems too small of a change to have any effect and going much further than that seems scary. I mean, mostly scared about wasting the money (I have power meter cranks, so added cost there too).
If you ride fixed gear, installing shorter cranks is immediately noticeable as you are more connected to the bike. The shorter cranks feel more comfortable and you can spin them up faster. I started with 170mm and a 48t chainring. It was tough to get up to speed and also stopping. Once I changed to 165mm and 44t chainring the bike came alive.
on a fixie, short cranks are just about required for cornering clearance.
@@samj1185 same with the halfbike I ride. It has really short cranks 145 or 150 but with a larger chainring than what is demonstrated on this video. My micro Pedalflow also has short crank arms with an extremely large chainring.
Yes, I have experimented with shorter cranks multiple times - simply because I use 180 mm cranks and they have been difficult to get decades ago and are almost impossible to get now. But when ever I rode bikes with shorter cranks (170 mm, 172.5 mm and 175 mm) it felt unnatural and very uncomfortable for me. So I sticked to 180 mm on all my bikes (even the TT) and I am very fine with them! …and btw, it was not easy to get them fit to the newer bikes and chain rings - but it was absolutely worth the effort and the money
Well, I’ve gone 172.5 to 175 (5’11 and 35 inch inseam). Sustained power is higher, and long climbs are faster. I do struggle to hold a sprint for as long though. But, other than CX racing, my racing days are over - so a sprint is less important. I do use 170s on the TT bike though.
All of my bikes have had 172.5mm cranks. I bought a groupset in the sale because it was too good a price not to have. They only had 170mm cranks left, so I thought it can't make that much difference. How wrong was I. Bloody brilliant.
I wentr to 165mm cranck with my gravel bike (i usually use 172?5 or 175mm cranck).
165 felt weird, i wouldn't feel any power in my legs but could spin super fast. It was also more confortable in term of hip and knee angle.
I'm now using 170mm cranck and feel it's the best for me
Interesting! Did you feel like you couldn't sprint on the shorter cranks?
@@gcn I was mostly riding to commute or bikepack so wasn’t interested in sprinting but still felt like i was missing on something when i was putting the power on the pedals.
Maybe it’s just in my head 🤷🏻♂️
I've come to believe that crank length +/- 5mm has a lot to do with your personal cadence. if you prefer a slower cadence a longer crank will suit you better and vice vera if you prefer a faster cadence. I think it's like an engine, longer stroke= lower RPM, shorter stroke = higher RPM for same output at the wheels after passing through the appropriate gear ratios.
Wow I'm super impressed, someone at GCN brought tools this time.
Seems like a good application for an oval chainring to help compensate for less leverage.
It's more the other way around. Unless you'd use the old biopace chainrings
Interesting! Should we do some testing on oval chainrings? 👀
@@gcn definitely. I'm 190 cm tall and ride 175 cranks but also tried 180mm. However that made my cadence a fraction to low. I did like the acceleration out of corners. Then I tried Q-rings. That got my cadence up a little because the pedal goers trough the less loaded phase of the rotation faster. It really feels good. And I always wonder why that never comes up in debates about oval chainrings. Unfortunately I had to many dropped chains shifting to the inner chainring right when you don't want them. So it's back to the 175's with normal chainrings. Where I to build a TT-bike or other 1b setup I'd probably go back to 180's with q-rings.
I had my bike custom made and sent in my measurements and they catered the whole bike based on those figures. I never second questioned those decisions.
Never mind crank length research, how about researching what arm length Conor needs on his coat!
Cool video, I get the theory about shorter cranks. But it seems to optimize them you would have to lower the bottom bracket because raising your saddle is definitely an aerodynamic disadvantage. You also have to retrain yourself as far as gearing and cadence. Its all about smaller gearing and higher cadence and that is not something you learn on a short ride. 5DEV is a really cool company, but not all those cranks are Titanium. The one you showed with the triangles cut out is for sure aluminum, making it significantly more affordable then their Titanium offerings. Hopefully somebody has done the math to figure out what is the new optimum crank length for riders depending on their inseam.
Getting Conor to do the test is a great idea. It will bring out the feel of having too short a crank more easily and effectively than someone with short legs.
Glad you enjoyed the video 🙌
I designed a custom bike in 1982. A big project. I wish I could supply sources, and my papers, but it has been many decades and sources were lost. I measured my distance between joints (foot, leg, thigh, hips). The frame geometry was radical, as were some other elements of design. The end of the project was 165mm crank length (ideal was about 166.5mm) and to this day the best bike I have ever ridden. Climbed fast, the geometry said it would be a terror on descents, but was actually very well mannered. Compensation was also allowed for frame material (wall, diameter, geometry, tube length). Pedal platform height was also a factor to be considered when considering crank length.
It's crazy that Conor uses 175mm cranks while some S size bikes come with 170mm cranks. Cranks definitely need more variation in sizing. Hip impingement is a short person problem and the reason why is obvious.
When I was a kid in the 1980s I had a cheap Western Flyer BMX that came with 5.5" (139.7mm) cranks and a 36-tooth chain wheel. I never gave any thought to crank arm length or tooth count until the neighbor kid got a real BMX; a Diamond Back. He let me try it out and it was amazing; I loved it. It had 175mm crank arms and a 44-tooth chain wheel, and even though I was only 11 or 12 years old at the time and only about 5 feet tall, it still felt way better.
I'm 6' 2" now and I have 180mm crank arms and 44/16 gearing on my BMXs. That setup has long been popular for BMXs (the racing oriented ones anyway); there were even some that came stock from the factory that way, like a 1980s Mongoose Pro Class for example.
I'm 175cm and went from 172.5 (stock) to 155. Took a handful of rides to get settled in, as it felt like I was riding a children's bike. But once I got used to them, I never looked back. Less knee pain, can spin faster, and more comfort since my seatpost is pulled out further.
I was on 155s some years ago and never had problems with my hips, though my fit was lacking in other departments. Then the crankset somehow melded with the chainrings and powermeter, so I chugged it. For whatever reason, I then got back on 172.5s. Now I'm on back on 160s after a break from cycling, and not only does my hip feel great, but I get a lot less sore/fatigued despite having lost heaps of strength. I'm literally down from 35kph averages to 25kph haha...
I switched from 175 to 165 a couple months ago. I have adjusted to it. I still notice that I don't have all the easy turning cranks when climbing, but that probably just allowed me to 'coast' or more easily rest through sectors of each chain ring revolution
That's great! It's always good when you find the perfect bike parts that fit you 🙌
I have used 170 for a long time and I still do on some bikes. But on my main recumbent I always have 160. For reference I am 178cm tall.
About 15 years ago I experimented with various length trying 175 and 153 (diy modification of cheap 175, just clamp them in a milling machine, allign everything and drill a new thread 22mm away from the original one). The conclusion was that 153 might be limiting me a bit. Something like mentioned in this video: they felt like accelerating is too hard with them, like it is difficult to spin up the rpm enough to feel comfortable to change to the next gear. But when cruising they were comfortable mainly for my knees that did not like the 175 at all and even 170 was taxing them a little. So I decided that expensive 160mm cranks could be worth it (no cheap 160 available to try) and bought them. I never went back.
For me personally I would also say that 160 on a recumbent feel similar to me as 170 do on an upright bike. Maybe how much your hips normally move when pedaling or something similar is a factor in that.
I have always found it baffling that there are several frame sizes of every (upright) bike and when someone comes into a shop to buy a bike they will get lots of advice on what size would be right for them. But then a person 150cm tall will get told to use 170mm cranks same as someone 170cm tall and a person 2m tall would get 175mm cranks recommended same as someone 175cm tall. I would very much like to see more crank sizes generally available so that we could all chose what feels best for our individual case.
I’m using the 170s that came with my bike. I haven’t had any pain issues, I’m comfortable, and my bike fitter didn’t feel the need to change, so I’ll likely keep using what’s working
I’ve recently switched from 170s to 145s as an experiment and it’s been a revelation! I’ve been able to drop my bars by over 90mm with the same hip angle.
But what about your speed and race times? This is the test. A race bike should be fast not comfortable....
what a weird statement… since you’re the driving force of the race bike, you need to be comfortable… only then it’s fast over a period of time… you seem to only sprint to the next cafe to make same bold claims
145! That is short 👀 Super cool that it's worked for you!
@@gcn Apparently, Greg Lemond said that if he was racing today, he’d be racing on 145s.
@@antonkruger5652 my speed is about the same, I’ll probably a bit slower on the climbs until my body adapts but I’m definitely already a touch faster on the flat and downhill.
I'm 6'6" and used to 170mm cranks on an old 7-speed cassette mounted to Mavic rims driving a Columbus Nivachrome custom frame.
Needed a second bike, so chose a 1985 vintage 'Frankenbike,' the owner modding all the running gear, which included 180mm cranks.
It took a few rides to get used to, but setting the seat a bit higher to accommodate the extra 10mm radius at both extremes (knee to chest a bit higher and foot extended lower) and I was pleasantly surprised.
Where the 180's excelled was with quick attacks on hills without changing gears, and using a smaller cog and lower cadence on the flats with higher speeds achieved without furious pedaling. Fast cadence accomplishes the same thing, but I felt more control over deliberate long muscle activation for more or less power with the longer stroke. That control over pressure into the pedal with the longer, higher torque crank was almost like changing gears, without changing gears.
I’ve had a dodgy knee (OA) for a few years now. Knee got progressively more painful. Went from 170mm (I’m 169cm) to 165 for a couple of years. Great but still got pain on long hilly rides. Went to 155cm Canfield cranks (more affordable than others) Jan this year for long bike packing trip on Epic HT - no pain, better comfort, less back pain 👍. Got another set for my Crux for gravel and CX - perfect!! They def work for me so thumbs up for shorter cranks! 👍
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One factor on crank length not taken into account here is saddle position. Horizontal placement won’t change rotation, but it will change the rise, and position of the joint. I understand we are now beginning to split very fine hairs. I was fortunate that the math, and comfort aligned. The true test is comfort, and efficiency over a very long test period.
One thing I did observe was saddle position. I saw a photo of Graeme Obree during a sprint. He was using the very front of his saddle. This is a whole new world to explore.
It is not about the length but the technique. At least that's what I keep telling myself.
Good think Conor has length and skill 😉
Wearing a winter jacket in june. England must be really cold. We got 35 degrees already in Romania 😅
Today in Exeter it has varied between 12-17 degrees depending if it is raining or sunny.
It's still technically spring here until the 21st and ... Yeah
We're hoping summer will turn up soon 👀
cane creek's eewings for road have a minimum of 170mm crank length. It is smart for 5dev to promote short crank arms. And it is valid too. for old riders, a light single speed with short cranks can be very fast
Seems like Connor would also have to change seat height, cockpit reach and maybe even the cassette to really optimize the smaller cranks
I got new cranks on yesterday, went from 170mm to 160mm, but I'm only 164cm so makes sense.
All my bikes had 172.5 cranks. I bought a secondhand Ultegra group set with 170mm cranks. It did make a difference. I eventually wore the chainrings out and it was cheaper to buy a nearly new 12 speed 105 chainset from eBay than the compatible chainrings for my old group set. The only thing was, my bargain chainset had 172.5 cranks. I did notice a slight difference going back up a length, but I feel I’m riding like I used to do. More out of the saddle as it feels better to me with longer cranks. I reckon it depends on how you ride. The thing that interested me was my eBay purchase turned up in a box marked 165mm. I think my bargain buy was simply down to the seller swapping to shorter cranks….
I’m 6’5. I’ve gone from 175’s to 165’s and I’m really enjoying it. My hip angle is so much more open, big days don’t feel as brutal and my pelvis is rock solid. The range of movement is lower so I feel like my force production from the glute is more potent and my hip flexors are more engaged. All round win.
I think a lot depends on body size - more importantly thing length. Shorter thigh bone= shorter crank. Having said that, I always rode 170 on the road and 165 on the track. I found the extra leverage could help me over a bump on the road and the shorter crank would allow me to rev higher wit hteh fixed gear if the bunch really got moving on the track.
5'7" have 165mm on one bike and 170mm on the two others. Tried 165mm from all the bike-fitting talk, to be honest, can't tell any difference. But definitely feel more secure cornering and maybe less rock strikes (on gravel bike).
I'm about to switch to 165mm from 172.5mm. I messed around with crank lengths 30-years ago at Uni, and found no higher energy cost or savings for different lengths, but this change has been forced by a bad accident last year. I already had a big leg length discrepancy, but after smashing up my pelvis, and with an arthritic knee, I just ache too much on the bike. So far, it feels much better on my Kickr Bike - test will come when I get out in the real world.
I only ride recumbents and 150 mm is the biggest cranks I ride. Love the 140 mm´s. For me the best fit and I would never go back. It definitly takes time to get used to them though. By the way I´m 190 cm.
Gone were the days that they made videos without sponsored elements, in totally hilarious Top Gear style of rubbish bikes challenges. The message is not in the crank length, it's just to showcase 5dev.
Lol I know I can't watch them anymore.
Okay, we have first impressions from Connor for each crank length - that's great. But the question "which crank is was fastest?" in the end is weird - just based on the presented results, one might conclude "longer = faster", slap on 175mm cranks and then face bike fit (i.e. comfort/sustainability) consequences of this change. Neill Stanbury's summary on this topic is far more reasonable, which, in short is: if comfort is your priority = shorter cranks, if doing kind of rides where instantaneous power is important (e.g. crit racing) = longer cranks.
If you are mashing uphill standing longer is faster. If you are spinning 150 rpm in an easier gear you will be able to hold it longer on shorter. 170mm cranks put about 9% more pressure on your knee than 165mm cranks.
When I had the Biopace chainring I loved it. They may not be appropriate for racing, but I think they may have a place for casual riders as well as ultra-distance racing. I’d enjoy seeing them tested.
i tried every option from 160 to 180mm. longer is better imo!
I went from 175 to 160's to see if they would help knee pain I was having. These things were a game changer for me. I can pedal without knee pain now! They might not be for everybody. But, I think a lot of people would benefit from trying.
Due to an accident in February 2018, I (177cm and 85.3cm inseam) catched a cartilage damage in my left knee (I got hit by a car as a pedestrian - the real dangers are where you expect them the least), and therefore tried shorter cranks than my since 1995 used 175mm, and tried 172,5mm. Although I even adjusted the saddle height (+2.5mm), the cranks respectively the pedalling felt uncomfortable, with added pressure in the "wounded" knee, so I switched back to 175mm. On the other hand, years before I also tried 177.5mm (as I ride Campy square taper since 2006, switching was not that difficult), but after about 30 minutes, my legs got heavy, and I felt I was losing power, so for me 175mm seem to be the sweet spot.
Looking forward to the long(er) term update on the 170! those 145s were hilarious though, made it look like a mini clown bike!
What a coincidence, I've been catching up on all the videos others have done on this topic and decided to swap to 152mm cranks (I'm 172 cm). The bike manufacturers try to simplify their inventory when building the different sizes, so I can see how they ignore this part of bike sizing, since it also helps their bottom line. Many cyclists who focus on performance are young & fit, so can adapt to less-than-ideal crank lengths without problem. But I'm getting older and having knee issues after long distance rides. So this is what motivated me to switch. I found a cheap set of cranks online, mostly fit square tapered spindles, which are slightly older design, but I also have cheaper (not the latest cutting-edge & expensive tech) bikes, so it's quite economical for me to switch to shorter cranks. Many short cranks are made for ebikes these days, which don't need the longer torque leverage anyway.
High cadence is *key* for maintaining power with short cranks. If I raise my saddle *slightly less* than the change in crank length, I feel more comfortable at the high cadences needed to compensate for lack of torque.
Allowing me to overcome knee issues after progressing from 135mm, the sweet spot for me (5'6") has been 153mm. Great pedal clearance at crit speeds, decent cda, and knee friendly.
I think getting Connor to do this one was a mistake, it really is far away from real world usage for 99% of us. Because of his size.
Yes i have modified my crank from length from 170mm to 150mm, i am 5,2" in height.. it has worked me wonder i am able maintain high cadence with good power.. and comfort is really good ..able avoid hip injury.. but need at least month to get used to it ...climbs can be bit difficult initially, once get used to you are going to enjoy shorter crank.
I have gone from 172.5 and 175 stock length to 170s and comfort and speed have improved. My fixie build however is 165 to prevent pedal strikes even though I think 170s would help a little with stability out the saddle. As Conor found, tall riders will find that the shortest lengths take things too far but shorter riders would make 155s work very well. The sweet spot is dependent on your own biomechanics but often that is one size smaller than bike brands spec for a given size frame.
Far be it for me to be simplistic, but basic high school physics tells us that a longer arm is going to provide greater leverage, so it's obviously going to provide more torque. But just like with cars, you can either have torque, or you can have power; but not BOTH. Increasing torque sacrifices power, while increasing power costs torque. Crank arm lengths have stayed the same because they represent the "happy medium" between torque and power (for average riders). For extreme race conditions, a shorter arm might be useful (like on a velodrome) because torque won't be needed to climb hills. Contrarily, a longer arm would be more useful on steep climbs.
I run 175mm on both my MTB and my road bike, because I'm 6'2" and I live where the terrain is very hilly. I need the torque for the ascents and the power for the descents.
I wonder if the super short cranks could help folks with some mobility impingements, or who may otherwise use the elliptical bikes - but would rather have a seated position.
I'm 6'8 and use 200 mm cranks. When I ride 170's they feel ridiculous. The downside is my bike frame needs to be designed for longer cranks (KHS 747 - Zinn)
I rode 152'5mm cranks for some time, years ago. There was no discernable power loss and I kind of liked them. But having a shorter crank requires having a lower BB, because otherwise I needed to raise the saddle. I run 180s now.
Easier to raise the saddle than lower the BB 😉
@@gcn But it raises the COG of the bike - making it sluggish. That and rising the saddle requires rising the bars - which may prove to be quite expensive. Overall - shorter cranks require a frame designed around them.
5'7 with a short 28" inseam. I've been running 140mm cranks and loving them on my bikes. Tempted to place with 150mm.
That's super short 👀 What is it that you are loving about them so much?
I went from 180 to 175 to 170 in the 90s against everyone's recommendations. I am still riding 170 but I have thought of trying 165.
I am 188cm 6,2
After having a Total knee replacement in right leg I couldn't cycle for a year or so due to pain and basically the knee didn't bend sufficiently to even turn the crank, very painful and on the odd day that I could cycle I found my right knee almost hitting my chest. After a lot of experimenting I eventually went from a 172mm Right Hand crank down to 125mm (the left hand crank is still 172mm). I can get on bike and pedal straight away, no pain...did this with all my bikes (had an engineering company reduce the length and drill new threaded holes for pedals. It looks odd but it works and gets me out on the bike.
I had a knee replacement and moved to 155 cranks to make it easier to get over the top of the pedal stroke. Defiantly a bit slower especially up hill than the 165 I was using but better for my knee. I’m 5’10” with short 30” inside leg
I had the opportunity to try different lengths during a bike fit and ended up with 170 instead of 175 that came with the bike. 165 felt like a kids bike which might be due to my long legs. Would be worth an investigation why most bikes still come with too long cranks and too wide bars.
Biopace is what I’m familiar with, I used it for years. It worked great other than if you wanted to sprint. I once had the back wheel start bouncing as I started up a steep hill out of the saddle.
Everyone has an optimal crank length; depends on what kind of rider you are and the type of riding you're doing. My biggest challenge was loss of leverage going to 170mm cranks I had to increase my cadence overall, so weighing pros and cons of shorter cranks they are beneficial for me. The biggest thing I noticed is how much better my legs felt after my ride. I have to think about longevity nowadays
About ten years ago I went from 175 MTB & 172.5 Road to 170 for both, and haven't looked back. Experiment and see what works for you. Cheers!
I used to have 170 cranks on all of my recumbents. I had no idea there were shorter crank sizes. My first velomobile came with 155 cranks. I didn’t notice any difference with the shorter cranks. Last fall I had a conversation with a velomobile designer about crank length. He suggested I try 140mm cranks because he had found he actually was faster with shorter cranks. I was shocked to find that my commute times did drop with 140mm cranks. Strangely enough, I actually accelerate and climb faster with the shorter cranks. I can spin more easily. I think my height (5’6”) and the recumbent position lend themselves to shorter cranks. I have some tall friends riding velomobile with as short as 130mm cranks and they actually find it comfortable and are still incredibly rapid riders.
I find you have a narrower power band with shorter cranks, I find myself changing gear more to stay at a certain cadence sweet spot. I think that is why mtbs come with 175mm cranks because of such rapid speed and gradient changes. It's similar to the difference between a 2 and 4 stroke dirt bike.
Great article, thanks Conor. Keen to know how the switch goes especially as I wonder if, at my age do I need to switch the older I get?
I've found that as I've got older (46 now), my hips are loads tighter than they used to be, despite stretching etc etc. I went shorter to 155s and it's night and day the difference. Only took a handful of rides to get used to the feel.
Im 178cm high and riding 165mm cranks and also mid foot cleat position.
It is very comfy and my normal cadence now is 105-110 rpm.
the argument for shorter cranks makes sense especially when I heard it from a physical therapist. however if we shorten crank length how are we supposed to fit our saddles and general fit? is our leg supposed to be slightly bent? and if we go shorter on the crank our leg will be bent more than just slightly and then how do we organize the rest of the bike? doesn't this slight adjustment and change flip the whole thing upside down on its head? shorter cranks up the power and consistency we put down lowering fatigue. GREAT. but no one is talking about the rest of the equation.