Dylan, FWIW I did my masters thesis in like 1980 on the effect of cranklength (150-200 mm) on oxygen consumption while cycling at a constant workload. I used competitive cyclists and the results did favor shorter cranks. The limitation was clearly that other than time trials the workload in cycling is constantly changing. At 6'1" I continue on 175's as that is what I am used to and have no other issues to address....except being 70 years old.
@@imsgoalie1 Never published as I went to medical school soon after. I am not sure if it is available from Penn State, (was actually 1981) and in looking at it is almost embarrassing now. We collected expired breath in giant bags and analyzed it to obtain VO2. Very primitive and hard to control all variables. Often think how much easier it would be to do today.
I’m 50 years old and have been riding bike since I was 4. I’ve never trained or was into racing. I simply road because I couldn’t see good enough to get a driver’s license. Over a decade I was riding an average of 125 miles a week just to go to work and back. 175 mm cranks at the time and have been steadily working my way down the scale. I currently ride 150 mm cranks because I’m 5 foot 4 and have an in seam of 28 inches. Now I can ride longer distances without my crotch falling asleep.
@@lisashiela9137 It cost me an arm AND a leg to get my used DA 9000 x 165s. Later DA versions don't suit my large Rotor QXL chainring stock. The RS510 x 165s for my 2nd bike, much lighter but much heavier too.
170cm tall, poor hip and knees, 140mm 👍 for years. Not for performance but it solves all the pain. It was an experiment I did (with mid foot position) after viewing fitting vids on Ur channel(s). And it works! Thanks a lot btw. But the gear (gain) ratio thing... shorter cranks need a lower gear ratio to get the same gain ratio-a term from the Sheldon Brown site.
welcome back Dylan! As a fitter from my side I can add: these marginals gains come not from biomechanical side of the leg-crank system, but physiological one. With exertion, muscle mobilizers/stabilizers come into account, when those enduracne depletes and leg pattern is distured, thus cutting effective pushing phase of legs in degrees significantly. So shortnening the open/close leg angles saves mobilizers/stabilizers for longer period of time. Cheers, Alexey
I went from 172.5 to 165 and got much less knee pain and saddle sores due to a more stable position. I also noticed a significant improvement in performance and speed, maybe due to the increased comfort and the ability to get more aero but the benefits have been very noticeable. great video hope manufacturers will catch on because not finding any bike that fits me anymore is a pain in the ass (even "custom" bike builds often don't feature anything below a 170)
Can you get your knee to your chest before 165? I feel what you've described is knee compression to your chest and being able to deep breathe would indicate why performance and speed increase.
The 20% inseam calculation worked for me. I'm at 925 mm, which comes out to a 185mm crank. Believe it or not, I did find 185mm cranks to put on my 62cm frame. They are expensive and heavy but still more comfortable than the 175s I replaced. People at the ends of the bell curve (short or tall) are the ones with the real crank-length issues. We're just too small a market to support good products from the manufacturers.
I'm 6' 2", but have a long back and relatively short legs with an inseam of 32.75". A new bike I got several years ago came with 175 mm cranks. I quickly noticed left knee pain. I switched to the 172.5 mm I had been using and this resolved. But sometime after that, I started getting more left knee pain. I looked into still shorter cranks and decided 165 mm looked good. I tired them and the knee pain dropped to a fraction immediately and was completely gone within a few weeks. I then converted all of my bikes to 165 mm. My short wife had 165 mm cranks on her bike. I converted to 152 mm and she immediately loved it. I could also see that she no longer looked like she was going to hit herself with her knees while pedaling. You do lose some leverage, but it's on the order of a half a step between gears and you only lose something at the very lowest gearing. I also believe the less range of knee motion means more of your pedal stroke is in a strongest or best leverage portion of the pedal stroke. Bottom line, I'm a believer in shorter cranks.
Now that's a good argument! Toe overlap. I run 172.5mm and 170mm cranks on 2 size 52 frames, and the toe overlap (especially with a front fender) is super annoying.
More smooth pedal cadence too and no knees hitting my chest on the drops due to higher seatpost, especially for us shorter guys who's already pretty tight on remaining seatpost length lol. Definitely one of the best upgrades I did as per my bike fitter recommendation.
Same here. I went over the years from 170mm to 165mm to 160mm. Each time I went shorter, I got more comfortable, less knee pain (none now with 160mm cranks), and smoother pedal stroke. According to the 20% rule I should be using 152mm cranks. I'm really tempted to try 150mm cranks but I would have to go off-brand, there are only a few choices, and SRAM AXS 2x12 front derailleur may or may not shift as well with other-brand cranks & chainrings. Toe overlap can be a major problem, not just an annoyance if you ride a small or extra-small road bike like I do. Especially if you wear larger shoes for your height (also as I do). Shorter cranks help with that and I also use pedals with wider q-factor (Favero Assioma Duo Shi) and this helps tremendously to reduce toe overlap as well as increased comfort and smoother pedal stroke. If you take some video from the front as you are pedaling, your saddle height is correct but your knees and legs make a v-shape, you are a good candidate for both shorter cranks and longer pedal spindles. A lot of fitters don't even look at this so do yourself a favor and ask them to take video from the front and evaluate. This often comes from hip impingement which is not from a lack of flexibility, but it's from the way your hip architecture is. This is more common than you might think, and it also affects deep barbell squats. Since going to the "Starting Strength" method of barbell squats, I can do deep squats for the first time in 25 years of barbell squats.
What's crazy is that in spite of the shorter crank trend, crank lengths on new bikes are still based on frame size and not an option by most manufacturers.
most of the bikes are bought in a store - that should be the advantage, store/seller should be able to customise the bike for you (without extra costs!), like, cranks, brakes, handlebar etc
The problem is that the big drive train company don’t offer correct length cranks. So it’s not like a bike shop can swap on correct length cranks when the bike already has the shortest crank Shimano or SRAM offers for a mid price bike. Everyone that is “trending” to correct length cranks are doing so by replacing bottom bracket and chain rings.
@@ervin7178shimano even has 160s which I use since I'm a tiny asian guy at 165cm. The default 170s my bike came with was too long despite being an xs frame. They should really allow choosing crank length from the start imo to prevent extra expenses.
Great video. As a pro bike fitter that does 75% tri fits, we have been onto this for some time now for the exact reasons you mention: hip angle tends to be the limiter in the TT/tri position, and you can only get so far forward (steep seat angle) before the weight distribution becomes silly. So shorter cranks, which reduce the knee height at top of crank cycle are the answer. Average size folks do indeed tend to gravitate to 160 or 165mm for tri (so the 18-20% crank length/inseam holds). We can switch crank lengths on our Vertex Fit Cycle while the rider is still on board and instantly adjust saddle height while keeping all other parameters constant, so it is easy to observe the rider's reaction to different crank lengths. Frequently 1-2 sizes shorter than they are accustomed to results in a very positive perception as far as power and efficiency. I hear "did you drop the power - this is easy now" all the time. (I don't drop it). At some point tho the rider dislikes the change - they become too short. Now this is likely affected somewhat by anchoring to their traditional crank length. But that said, after 10 mins on the new shorter cranks, I switch them back to their traditional length and they hate them. They may have been riding 172.5 for decades, and after 10 mins on 165 they hate the 172.5. I have never seen anyone (thousands of fits) go longer again. Road is less cut and dry than tri/tt, it's far easier to get away with long cranks for road as many riders aren't hip-angle limited on a road bike (shorter riders tho typically are). But for sure the knee flexion thing can be significant. I had a very tall guy who had struggled with knee pain his entire life - but he loved cycling and so rode thru the pain for decades. "Laughably short" 155mm cranks (~37" inseam so 16% crank length/inseam) cured him instantly. One easy test for the reasonableness of traditional 165-175 crank lengths: that's a 6% variance in lengths. Saddle heights commonly vary more than 40%.
I'm 6' and ride L/XL frames. I rode 165 cranks my whole childhood / college (I think my dad was mostly motivated by reduced pedal strikes at high lean angle). Then my first carbon bike purchased as an adult came with 172s, so I have that on my road/gravel bikes. But on the track, shorter cranks are advantageous because comfort and efficiency at high RPMs is such a big factor (also pedal striking at some velodromes, though not mine). So on track, I run 165s. They certainly feel a little different but I don't think it's a big deal. I only race track and the 172s on the road aren't bugging me, so I'm not rushing out to replace them ($$$). Interesting video!
Dylan, welcome back to science! We all been dying out here as we waited. 😉 At 6'2" on 61cm framesets, I moved to 180s 16 yrs ago but when I revamped my bike positioning earlier this year, dropped to 165s. Knees are now 30mm lower, stem is lower & longer and my short saddles are forward now too. I'm no pro but it's working for me.
Finally ! a Dylan Johnson video ! I changed from 170 to 160 and I love it. I love the shorter cranks for these reasons : 1 - no more fear of pedalling in corners (I still have to be cautious) 2 - no more hitting the front tire if I turn my handle bar a lot 3 - faster cadence, even when I'm not trying. 4 - less knee and hip pain I might try 150 or 155 mm on my second bike ... we'll see
I'm 5'9"...I've been running 150mm on my road, mtb and gravel bike for the better part of 8 years. Its just more comfortable and once I got used to it I can't find any down sides... other than finding manufactures who make 150 cranks is a little tough sometimes.
I have been riding for 30 years, and I switched from 170mm to 165mm cranks. I did several tests of 3 different TrainerRoad sessions over several weeks. And I consistently pushed 20watts more at 5bpm less.
That's interesting, I'm imagining the difference is in the load of moving your legs further. Our legs weigh a hefty few kgs and with longer cranks they move further i.e. they are lifted higher on each stroke.
I went from 175 to 170, the difference I felt was incredible. Much smoother pedal stroke and more fluid power transfer, not to mention the added comfort when on the drops. I’m 193cm with a 95cm inseam. Going off this calculation I’d need 190mm cranks 😳 no thanks 🤣
I went from riding 172.5mm to 180mm cranks. Immediately, I was faster, a better climber, better results in races. Yet, I'm still a fan of 'shorter cranks', compared to conventional lengths that have been most common. Why? I'm 194cm tall with a long 94cm inseam. 180mm cranks is basically 19% of my inseam. My overall height is 109% of Dylan's height (approx. 178cm). 109% of 165mm cranks you now use is 180mm, which I use. I would concur that typically, that 18% to 20% is the sweet spot. I watched your earlier UA-cam video from 2 years ago, and I'm glad that you acknowledged that this new video, with further research, you've adjusted your opinions on crank lengths. Thanks for the great video! For those who are shorter riders, like 5'3" (160cm, ideally you should be on 150mm cranks, up to 155mm. It's crazy that most bikes coming out in XXS sizes, still typically come with 170mm cranks, which are arguably more suitable for someone around 5'11"
Great comment. Yes - I think short cyclists are often afraid to go short enough for cranks, and tall cyclists are often afraid to go long enough. I have a 77.5 cm inseam (I’m 5’8”) and use 150s, which is basically the same ratio as you use.
As someone who rides 49CM/XS frames, I always thought it was insane that brands would spec the same size cranks as a medium or even a large. I used to only run 170mm cranks and would constantly deal with knee pain and feeling like there were "dead spots" in the pedal stroke. I'm on 165mm now - which even that small change has been a noticeable improvement. I'm probably going to go even lower to 160mm soon
Ok, lets put that to the test. The earth is not a spinning ball/globe. The earth is a flat stationary plane. This is absolute. Every test and all the evidence show the earth to be stationary and flat, and no test and no evidence shows the earth to be the 100% fake science fiction spinning cartoon ball you have all been indoctrinated to believe in. So, are you going to receive this truth?
That’s one thing I did when I got into cycling and triathlon. My tri coach said look I’m not gonna lie to you. You are 5’4” non of the big companies make cranks for you. After bike fitment we went with 155mm and boy was that amazing. I run them on all, road, tri and MTB. It’s the first modification i do from now on.
My two best one-day performances ever on the bike came earlier this season on 170mm cranks. Coming from 172.5mm. I'm 6 feet tall. One might argue that the 2.5mm crank length difference is insignificant, but really it's more like 5mm in total diameter. Especially if you raise your saddle accordingly. That marginal difference (for me) allowed me to sustain a more aggressive position on the bike for longer, increased my cadence, and mitigated potential quad cramps during higher efforts 3-4 hours in. No power loss in my sprint either. The only area not so great is climbing out of the saddle.
You guys are way more sensitive than me! Almost 70 years old, been riding bikes starting with those one-piece, forged steel, chromed things that came on Schwinns. What length were those? Rode 170 mm for years until a free crank with 172.5 came around. Couldn't tell any difference and rode MTB's with 175's for years. There's one of those hanging in my shop now that I rode last week. Had some road bikes with 175 mm cranks too. Switch between all of these bikes and don't notice any difference - no knee pains. Same saddle height on all of 'em. I was never fast but just lucky? I have two modern gravel bikes that I ride regularly - couldn't tell you right now what the the crank length on either of them is...but I'd guess 170 mm? IMHO people make a much bigger deal of this than it warrants...kind of like waxing your chain?
key word: trend. I've been doing this for a long time and have gone thru several trends over the years. Pass on changing my bike setup for yet another trend
There are 2 rather obvious advantages for longer cranks: 1. My bike already has “long” 172.5mm crank on the right. 2. My bike already has “long” 172.5mm crank on the left. Both are rather essential advantages compared to absent “short” cranks from either of my bike’s sides.
So glad to see these videos are back! Can't wait to hear your latest tire testing results with the race kings and would love to hear your thoughts on all of the available suspensions systems for gravel racing. Thanks!
Glad this is your first video in the off season! I went 5mm shorter about six weeks ago, and dang, for once I am super happy to be on the bandwagon. I am much more comfortable on my primary bike, and I will be converting my other bikes. I wish I had figured this out a long time ago!
Thanks, Dylan, and congrats on 12th overall! I had been wondering as about all I care about is where you finish, other than who won, of course. But winning isn't everything and good for you to be on that circuit and representing for the privateer, sort of the dream for lots of us. 😀
I'm 6' 4" but switched from 175mm to 165mm cranks about 3 years ago so I guess I'm ahead of the curve! I switched after reading the research which affirmed there was no effect on power output but it did help with hip impingement which is something I used to suffer with. I think it has also helped with increasing my cadence slightly where I used to be a bit of a grinder but that might just be because I am getting older, 😁 Other advantages of shorter cranks are reduced chance of pedal strikes and lighter weight.
I went from 175 to 165 and it really improved my cycling experience. It improved my performance in the drops, and it alleviated post-ride knee and hip soreness.
been riding 140mm cranks for years, my father has been riding 145mm cranks for even longer. he's 5'10 and I'm 6'2. It's funny seeing everyone start using things like forward seat posts, short cranks, aero bars, and narrow bars. all things we used to get laughed at for. fit all comes down to what feels best. right now it's fairly hard to find things that short, hopefully people will start listening and make some shorter cranks.
@@einundsiebenziger5488 I use origin 8, and box. short cranks made for square taper bottom brackets are relatively available, but for any other BB standard you have to go custom. some brands run you $500-$700+. you can drill holes in pre existing cranks if they're solid and you have the tools to be precise.
I accidentally went from 165 to 175mm cranks on my Enduro bike, and I became more comfortable. I destroyed my cranks on a wreck, and asked my LBS to order some new ones. They accidentally ordered the 175's and put them on. After a few pedal strikes I adapted to the longer cranks, I just thought my riding was sloppy. I instantly felt better, but didn't give it a lot of thought. When I got my first gravel bike, it had 165's and I had knee pain. I sold that one and got another bike that came with 170 and no knee pain. My new roadie came with 172.5 and no discomfort. I ride roughly 20 hours a week, I'm not low volume. While not a race, I did go solo for a 100k Fondo last weekend and was first on the course. Yes, solo for the entire 60 miles, I never drafted a single person. So fitness is okay (it wasn't a race of course). I did 130 miles that day. I'd like to find some short cranks for my 5' tall girlfriend, but at 5'7", I sm sticking with 175 if I'm buying new cranks. Fun fact: I went to a local, well regarded local fitter a couple years ago. After over 100,000 miles of riding, I thought I had my fit pretty well worked out...and I was right. I basically threw away $400 as all of his recommendations had me in pain. So, maybe I'm an outlier.
Went from 175 mm to 165 mm on TT bike. Helped with breathing, ftp not affected, but I just couldn't put the same power out on the short hills. Split the difference and went to 170 mm. btw, long femurs make you less sensitive to crank length (so my fitter told me) and help with climbing. I live in a hilly area so I'll stick with 175 mm on road and MTB.
Another advantage of shorter cranks is increased ground clearance. It'll get you a steeper max "pedaling bank angle" during turns. Also nice on rocky terrain.
Cranks, stems, bars, saddles, chainrings, cassettes ... in an ideal world all bikes would come with all of these parts configurable, just like they come out of the box without pedals.
@@georgeorwell7776my 2022 size M giant reign-e came with 160mm cranks, they must have went with it mainly to reduce pedal strikes because of a lower-ish BB height. It feels so good
Very nice video! I went 165 mm the past year, I do not pedal a lot but I preferred them in order to have a winder hip angle and a lower range of motion for touring. Long days on the saddle are better without pain 😅
I think you are missing some other advantages of shorter cranks: less toe overlap with the front wheel, also harder to get pedal strikes on corners. Those differences could also be utilized for different frame geometry. With less toe overlap, you could shorten the wheelbase to give an advantage in cornering. That could be a significant advantage in Cross or crits.
I don't think that toe clip overlap is an issue other than for maybe kids and casual cyclists. I'm sure all my bikes overlap but I don't recall ever touching
@@gbshaun It's a major pain when commuting or navigating tight bends at crosswalks. One of my roadbikes has notable overlap - I've raced it for years without a problem but very annoying for training when going slow and manoeuvering.
I’m 6’7” and switched to 165mm on my mountain bikes. Knee pain gone! Seems like it worth experimenting with… there might not be a best option for a given height.
Exercise physiologist and bike fitter here. Thanks for pointing out that the answer is always “It depends”. As is with nutrition, training, etc. One point to add as I think cyclists can benefit from zooming out sometimes. Yes this has a net positive reaction on the majority of riders and bike fits. Not that it’s wholly optimal across the board. Cold plunges help almost everyone, but because everyone’s dopamine function is pretty suspect in our polarizing world. Shorter crank arms help, but most cyclists are still hyperoptimizing that context alone. If you happen to learn that you’ll benefit from shorter crank arms than your physics can tolerate, you have some dysfunction. Apart from performance, time under tension, metabolic cost, etc. For human performance you have a limiting factor within your hip or ankle mobility and function. You need to treat a symptom for sure, but if that permits you to disregard all planes of motion, function, and stability you’ll still always be limited. I’m pro short crank arms for the masses and the industry shift, but it shouldn’t let you steer away from optimizing all aspects of the body for the sake of longevity
I have a commute bike with 172.5mm cranks, and my prop road bike has 165mm cranks. And while time on my commute bike is much less i have noticeable knee pain. On my regular road bike i have zero knee issues even after monster rides. Anecdote, absolutely. But in future every bike i have will have 165mm cranks, even as a 192cm rider.
@@tp3293yeah but I found myself getting locked out in a dead spot while climbing rocky trails more often (less torque to overturn the cranks?). Sometimes it felt like I was climbing using a second gear but at a first gear speed on 165s. Went back to 175s and chugging uphill over rocks feels just more fluid.
We sure have come a long way over the last 25 years on this topic. At 6’1” with relatively short legs and a lot of flexibility I used to run 175s for Mtb and road. I dropped to 172.5 for road and saw zero downsides, then followed with a drop to 170 for mtb and loved it immediately; only benefits perceived. For 2023 I took the leap and went to 170 for the dropbar bike I do everything on, and gave it a good shake. Ultimately, I couldn’t convince myself that 170 worked better for me in any way than 172.5. If anything, I kept thinking I had a bit more weight on my hands than I wanted, and my sweet spot cadence range didn’t seem to jive (I’m an 85rpm guy). I swapped back to 172.5 for 2024, and haven’t looked back. In Oct I rented a Giant TCR while in Portugal, and did about 900km on it in the Algarve. It has 175s, and they felt like crap. Both knees also showed signs of strain here and there. Looking at mainstream 58cm bikes on offer these days, it seems many brands are still into g 175s, which is ridiculous in my view. I can’t see them making sense for anyone under 6’5”. Similarly, 44cm bars. What, really?!
To provide an N=1 counter example to your conclusion. When I was racing on the track (Burnaby Velodrome, 200m) about 10 years ago I quickly found that while I could barely keep up with the "B" group (avg speed 44kmh) on the mandated 88" gearing, I could hang easily with the A group (avg speed 48kmh) if I raced on much larger gearing. Typically 96"-100". Effectively (as a non-sprinter Time Trialist) I was limited mostly by cadence. an 88" gearing required a much higher cadence (> 110, and as high as 130). The much larger gearing allowed me to keep cadence mostly below 110. Moving up to 175 mm on my track bike also helped me (although this was subjective). That allowed a larger front ring and a smaller cog, which reduced cadence as well. None of this helped with sprinting. But when there were B races I could enter that did not have gearing restrictions, I could easily work the front and tire the pack out, reducing their ability to sprint as well, especially in longer points races and point-a-lap races.
As a fixie nerd I started with 165mm cranks and I love that on my road bikes now and other track bikes. 165mm on my Enve Melee & 167,5mm on SWorks Venge
I have dropped to a 165mm cranks. This was for comfort. It opens up the movement in the legs, and as an older rider - it just makes sense. As for “speed performance” I am still slow! I am just more comfortable.
I am 170cm (~5'7), I switched exactly from 172,5mm down to 165mm. I am a hobbyst, rookie at best, but still could feel the difference. Much-much confortable on longer rides
I've missed these videos -- glad you're back. I most appreciate the thorough analysis (20% of inseam recommendation is for sprinting!) Hey! Even fitness cyclists can be interested in geek.
My main road bike is a 1977 Raleigh Grand Prix, which fits me but, compared to modern bikes, is huge. It came stock with 165mm cranks. I wonder when the industry lost the knowledge that this was an optimal crank length? My theory is that it's like how skinny tires feel fast, so it took a long time to break from that (and lots of folks still haven't). Mashing on a 175mm crank feels like you're really doing some work and probably feels more powerful than a shorter crank, along with bro-science "longer lever means more torque" type thinking, so that's what people were asking for and it became the standard.
I eco all the comments that “you are back” at least for the time being. Missed those kinds of videos. There is plenty of other people out there saying the same. About to give it try, soon.
I was gonna buy 165 cranks anyways for my new, xc bike, because I like them so much on my e enduro, the video is very interesting and makes me get them even quicker.
I very much appeciate your conclusions. As unclear as the science has been for decades, your summary agrees very well with my anecdotal observations over the last 45 years and what has continually frustrated me about the bike industry in this regard since the 80's when we moved from 165 and 170 cranks as standard along with 38 cm handlebars. Thx.
I'm 6'1" and went to 165mm cranks on my 1BY MTB. It is the bike I ride the most these days. Faster cadence at low speeds helps with balance on features and with missing obstacles. My Salsa came with a 30T (too low) and I put a 34T oval on it. I'm absolutely going to convert all of my bikes to 165's. I'm faster than most of the people I ride with anyway, and I do have occasional knee issues. Seat comfort, with less rocking seems better too. I also moved my shoes forward a bit after watching a video on avoiding the old "ball of foot" suggestion. Then I put a cane creek stem on my gravel bike, and that was a game changer too! Just go ride what you have. ;)
Thanks for supporting my confirmation bias 😁 I'm slightly taller than most (186cm or 73") and I've gone to 170mm cranks on all my bikes. I'm not convinced about sprint performance, but holding an Aero position in a breakaway is much easier.
Good analysis. I like how you used research papers. Now the industry needs to catch up because I’ve found it hard to find shorter cranks. I went from 172.5 to 165, then tried cheap 160s on a klunker bike and it was even better. I now have an even cheaper set of 152mm sitting in a box I want to try. I’m 5’8” average proportions 31” inseam. My hips feel better, knees much better and I feel like higher cadence spinning is easier. Wish I did this decades ago - I’m old and I’d recommend it to younger people.
5’7”. Rode 175 for decades. Went to 165 a couple years ago and wish I would’ve done it a long time ago. So much more comfortable and it feels easier to generate power.
I switched to 165mm cranks 6 years ago. I can definitely push the crank over the top better with them. I use to be able to get 165s dirt cheap. Now I can’t even find them
Great video. I've been on 175 cranks for years, had several bike fits over that time and never has the fitter told me to size down. For reference I have a 33 inch inseam. One thing I have done is gone to zero offset seat post which effectively steepens the seat tube. This allows the rider to get lower without decreasing the angle at the hips. It has worked for me. That said I have experimented with shorter cranks. I loved what it did for my cadence. But I hated what it did to my center of mass. When I went shorter I raised the saddle to maintain the knee angle at the bottom of the stroke. I did not like the feeling of sitting higher, especially off-road. I consider myself lucky in that I can ride with the cranks spec'd by bike companies. But I agree that shorter is likely the better call for most riders.
well made video. thanks. I only hate it that people only follows what the Pros are doing. long time ago my trainer wanted for us to use shorter cranks, but some where arguing that no high performance athletes were using them.
I switched to 165mm on my mtb about 7 years ago and never looked back. I got a gravel bike at the beginning of the year and it too came stocked with 172.5mm cranks. Switched over to 165mm about 4 months ago and will never go back to a longer set. Just feels better!
On more than a few occasions over the many years I have been selling bikes, I have recommended shorter cranks to customers with knee pain. In every case they had a reduction in pain. DT
Hi Dylan I suggest that out of saddle climbing is benefited by longer cranks, as torque is linearly related to crank length. So for the same applied power, your applied torque will increase. 175mm cranks will increase torque 6% over 165mm. That's obviously a significant advantage on climbs.
GREAT to have science Dylan back!! What about the aero penalty for having to raise the saddle as well as handle bars when going shorter cranks? Also possible aero penalty of higher cadence? BTW I went lower in crank length Actually it’s more important to match to tibia length instead of leg length
There is no aero penalty because you are now able to bend more at the hips and get your body into a lower more aero position, this might not apply if you're one of those riders I see out there riding around upright on the hoods (most of them) but for us that like to ride in an aero position it really is the main benefit of going down in crank length. You put the seat up to compensate for the higher position of the lower pedal so that relationship stays the same, no aero loss there, but your total height is reduced because you can lower your upper body to be more aero, usually you don't even need to raise the handle bars and definitely not the same as the amount you have to raise your saddle. My cadence varies all the time, I've never considered it to be an aero penalty at higher cadences. My range is between 60-120rpm when riding a single speed. On a geared bike I just ride which ever cadence feels comfortable, I don't try to maintain any mythical optimal cadence and the range is wide.
Dylan, FWIW I did my masters thesis in like 1980 on the effect of cranklength (150-200 mm) on oxygen consumption while cycling at a constant workload. I used competitive cyclists and the results did favor shorter cranks. The limitation was clearly that other than time trials the workload in cycling is constantly changing. At 6'1" I continue on 175's as that is what I am used to and have no other issues to address....except being 70 years old.
Did you publish at all? Could be a very interesting read (the data in particular).
@@imsgoalie1 Never published as I went to medical school soon after. I am not sure if it is available from Penn State, (was actually 1981) and in looking at it is almost embarrassing now. We collected expired breath in giant bags and analyzed it to obtain VO2. Very primitive and hard to control all variables. Often think how much easier it would be to do today.
@@jkevincarmichael253 Nothing embarassing there, we investigate with the tools we have. Just sounds like resourceful experiment design to me.
@@imsgoalie1 It was fun and with all the talk/data re: shorter cranks I feel like my findings were somewhat vindicated.
I’m 50 years old and have been riding bike since I was 4. I’ve never trained or was into racing. I simply road because I couldn’t see good enough to get a driver’s license. Over a decade I was riding an average of 125 miles a week just to go to work and back. 175 mm cranks at the time and have been steadily working my way down the scale. I currently ride 150 mm cranks because I’m 5 foot 4 and have an in seam of 28 inches. Now I can ride longer distances without my crotch falling asleep.
I'm going to order a 15mm crank. Thank you, Dylan.
Username checks out
I'm going to get some that are negative length.
@@jeff_aurand just put extra long rotated 180 degrees. Might get them on cheap too since everyone is switching over to short.
Due to all the upcoming UCI world tours, all 15 mm crank sets are on backorder.
@@lisashiela9137 It cost me an arm AND a leg to get my used DA 9000 x 165s. Later DA versions don't suit my large Rotor QXL chainring stock.
The RS510 x 165s for my 2nd bike, much lighter but much heavier too.
Thanks Dylan, I can now use my long cranks as an excuse for not being aero or fast enough.
The bloke with bad hips and knees. 👋 thanks for the shoutout Dylan 🤣 top vid as usual
My 2 favorite cycling channel. Eyyyyy ❤
170cm tall, poor hip and knees, 140mm 👍 for years. Not for performance but it solves all the pain. It was an experiment I did (with mid foot position) after viewing fitting vids on Ur channel(s). And it works! Thanks a lot btw.
But the gear (gain) ratio thing... shorter cranks need a lower gear ratio to get the same gain ratio-a term from the Sheldon Brown site.
Happy to see you back
welcome back Dylan!
As a fitter from my side I can add: these marginals gains come not from biomechanical side of the leg-crank system, but physiological one. With exertion, muscle mobilizers/stabilizers come into account, when those enduracne depletes and leg pattern is distured, thus cutting effective pushing phase of legs in degrees significantly. So shortnening the open/close leg angles saves mobilizers/stabilizers for longer period of time.
Cheers,
Alexey
For offroad, shorter cranks also have the advantage of less pedal strikes
@@harryparkinson this is very true!!!!
I went from 172.5 to 165 and got much less knee pain and saddle sores due to a more stable position. I also noticed a significant improvement in performance and speed, maybe due to the increased comfort and the ability to get more aero but the benefits have been very noticeable. great video hope manufacturers will catch on because not finding any bike that fits me anymore is a pain in the ass (even "custom" bike builds often don't feature anything below a 170)
🤔
Can you get your knee to your chest before 165? I feel what you've described is knee compression to your chest and being able to deep breathe would indicate why performance and speed increase.
The 20% inseam calculation worked for me. I'm at 925 mm, which comes out to a 185mm crank.
Believe it or not, I did find 185mm cranks to put on my 62cm frame. They are expensive and heavy but still more comfortable than the 175s I replaced.
People at the ends of the bell curve (short or tall) are the ones with the real crank-length issues. We're just too small a market to support good products from the manufacturers.
I'm 6' 2", but have a long back and relatively short legs with an inseam of 32.75". A new bike I got several years ago came with 175 mm cranks. I quickly noticed left knee pain. I switched to the 172.5 mm I had been using and this resolved. But sometime after that, I started getting more left knee pain. I looked into still shorter cranks and decided 165 mm looked good. I tired them and the knee pain dropped to a fraction immediately and was completely gone within a few weeks. I then converted all of my bikes to 165 mm.
My short wife had 165 mm cranks on her bike. I converted to 152 mm and she immediately loved it. I could also see that she no longer looked like she was going to hit herself with her knees while pedaling.
You do lose some leverage, but it's on the order of a half a step between gears and you only lose something at the very lowest gearing. I also believe the less range of knee motion means more of your pedal stroke is in a strongest or best leverage portion of the pedal stroke.
Bottom line, I'm a believer in shorter cranks.
I went from 170 to 160. No toe overlap, no pedal strikes, slightly higher cadence, and most importantly it just feels better.
Now that's a good argument! Toe overlap. I run 172.5mm and 170mm cranks on 2 size 52 frames, and the toe overlap (especially with a front fender) is super annoying.
More smooth pedal cadence too and no knees hitting my chest on the drops due to higher seatpost, especially for us shorter guys who's already pretty tight on remaining seatpost length lol.
Definitely one of the best upgrades I did as per my bike fitter recommendation.
Hey, thanks for sharing. Super informative. If you don’t mind me asking, what is your inseam and overall height?
Same here. I went over the years from 170mm to 165mm to 160mm. Each time I went shorter, I got more comfortable, less knee pain (none now with 160mm cranks), and smoother pedal stroke. According to the 20% rule I should be using 152mm cranks. I'm really tempted to try 150mm cranks but I would have to go off-brand, there are only a few choices, and SRAM AXS 2x12 front derailleur may or may not shift as well with other-brand cranks & chainrings.
Toe overlap can be a major problem, not just an annoyance if you ride a small or extra-small road bike like I do. Especially if you wear larger shoes for your height (also as I do). Shorter cranks help with that and I also use pedals with wider q-factor (Favero Assioma Duo Shi) and this helps tremendously to reduce toe overlap as well as increased comfort and smoother pedal stroke. If you take some video from the front as you are pedaling, your saddle height is correct but your knees and legs make a v-shape, you are a good candidate for both shorter cranks and longer pedal spindles. A lot of fitters don't even look at this so do yourself a favor and ask them to take video from the front and evaluate.
This often comes from hip impingement which is not from a lack of flexibility, but it's from the way your hip architecture is. This is more common than you might think, and it also affects deep barbell squats. Since going to the "Starting Strength" method of barbell squats, I can do deep squats for the first time in 25 years of barbell squats.
@@irfuel 2.5 mm is a whopping .0984252 inch, that's half of 1/8 inch!
What's crazy is that in spite of the shorter crank trend, crank lengths on new bikes are still based on frame size and not an option by most manufacturers.
most of the bikes are bought in a store - that should be the advantage, store/seller should be able to customise the bike for you (without extra costs!), like, cranks, brakes, handlebar etc
I wouldn't mind not being able to choose the crank length if they paired the optimal crank length with every size in the first place.
The problem is that the big drive train company don’t offer correct length cranks. So it’s not like a bike shop can swap on correct length cranks when the bike already has the shortest crank Shimano or SRAM offers for a mid price bike.
Everyone that is “trending” to correct length cranks are doing so by replacing bottom bracket and chain rings.
@@MrGoodachessram and shimano both make 165’s
@@ervin7178shimano even has 160s which I use since I'm a tiny asian guy at 165cm. The default 170s my bike came with was too long despite being an xs frame.
They should really allow choosing crank length from the start imo to prevent extra expenses.
Great video. As a pro bike fitter that does 75% tri fits, we have been onto this for some time now for the exact reasons you mention: hip angle tends to be the limiter in the TT/tri position, and you can only get so far forward (steep seat angle) before the weight distribution becomes silly. So shorter cranks, which reduce the knee height at top of crank cycle are the answer. Average size folks do indeed tend to gravitate to 160 or 165mm for tri (so the 18-20% crank length/inseam holds). We can switch crank lengths on our Vertex Fit Cycle while the rider is still on board and instantly adjust saddle height while keeping all other parameters constant, so it is easy to observe the rider's reaction to different crank lengths. Frequently 1-2 sizes shorter than they are accustomed to results in a very positive perception as far as power and efficiency. I hear "did you drop the power - this is easy now" all the time. (I don't drop it). At some point tho the rider dislikes the change - they become too short. Now this is likely affected somewhat by anchoring to their traditional crank length. But that said, after 10 mins on the new shorter cranks, I switch them back to their traditional length and they hate them. They may have been riding 172.5 for decades, and after 10 mins on 165 they hate the 172.5. I have never seen anyone (thousands of fits) go longer again. Road is less cut and dry than tri/tt, it's far easier to get away with long cranks for road as many riders aren't hip-angle limited on a road bike (shorter riders tho typically are). But for sure the knee flexion thing can be significant. I had a very tall guy who had struggled with knee pain his entire life - but he loved cycling and so rode thru the pain for decades. "Laughably short" 155mm cranks (~37" inseam so 16% crank length/inseam) cured him instantly. One easy test for the reasonableness of traditional 165-175 crank lengths: that's a 6% variance in lengths. Saddle heights commonly vary more than 40%.
For the same hip and knee flexion from folks 4'6" to 6'6", we should be seeing a much greater range in crankarm lengths.
I'm 6' and ride L/XL frames. I rode 165 cranks my whole childhood / college (I think my dad was mostly motivated by reduced pedal strikes at high lean angle). Then my first carbon bike purchased as an adult came with 172s, so I have that on my road/gravel bikes. But on the track, shorter cranks are advantageous because comfort and efficiency at high RPMs is such a big factor (also pedal striking at some velodromes, though not mine). So on track, I run 165s. They certainly feel a little different but I don't think it's a big deal. I only race track and the 172s on the road aren't bugging me, so I'm not rushing out to replace them ($$$). Interesting video!
“Dude, that’s what I been trying to tell my girlfriend”😂same buddy
😂
Dylan, welcome back to science! We all been dying out here as we waited. 😉
At 6'2" on 61cm framesets, I moved to 180s 16 yrs ago but when I revamped my bike positioning earlier this year, dropped to 165s. Knees are now 30mm lower, stem is lower & longer and my short saddles are forward now too. I'm no pro but it's working for me.
Finally ! a Dylan Johnson video !
I changed from 170 to 160 and I love it. I love the shorter cranks for these reasons :
1 - no more fear of pedalling in corners (I still have to be cautious)
2 - no more hitting the front tire if I turn my handle bar a lot
3 - faster cadence, even when I'm not trying.
4 - less knee and hip pain
I might try 150 or 155 mm on my second bike ... we'll see
I'm 5'9"...I've been running 150mm on my road, mtb and gravel bike for the better part of 8 years. Its just more comfortable and once I got used to it I can't find any down sides... other than finding manufactures who make 150 cranks is a little tough sometimes.
@@dirtrambler Nice to know. Which brand did you buy for your road bike?
I don't wanna buy those 500$ cranks lol
@ I I I found some Rotor cranks used , before that Origin 8 square taper, before that Crupi Expert BMX cranks actually worked great as well
@@musclelessfitness2045check out magene power meter cranks, i got them on sale for 200€
I have been riding for 30 years, and I switched from 170mm to 165mm cranks. I did several tests of 3 different TrainerRoad sessions over several weeks. And I consistently pushed 20watts more at 5bpm less.
That's interesting, I'm imagining the difference is in the load of moving your legs further. Our legs weigh a hefty few kgs and with longer cranks they move further i.e. they are lifted higher on each stroke.
I've been watching your clips since 2020 and it's good to see you back after a while!
In my teens, I used 165mm cranks. In my 50's I switched to 175mm, found a slower cadence more comfortable. Now in my 70's still prefer 175mm cranks.
What's your height?
I went from 175 to 170, the difference I felt was incredible. Much smoother pedal stroke and more fluid power transfer, not to mention the added comfort when on the drops. I’m 193cm with a 95cm inseam. Going off this calculation I’d need 190mm cranks 😳 no thanks 🤣
You are the Pogacar of cycling science on youtube.
I went from riding 172.5mm to 180mm cranks. Immediately, I was faster, a better climber, better results in races. Yet, I'm still a fan of 'shorter cranks', compared to conventional lengths that have been most common. Why? I'm 194cm tall with a long 94cm inseam.
180mm cranks is basically 19% of my inseam. My overall height is 109% of Dylan's height (approx. 178cm). 109% of 165mm cranks you now use is 180mm, which I use.
I would concur that typically, that 18% to 20% is the sweet spot.
I watched your earlier UA-cam video from 2 years ago, and I'm glad that you acknowledged that this new video, with further research, you've adjusted your opinions on crank lengths. Thanks for the great video!
For those who are shorter riders, like 5'3" (160cm, ideally you should be on 150mm cranks, up to 155mm. It's crazy that most bikes coming out in XXS sizes, still typically come with 170mm cranks, which are arguably more suitable for someone around 5'11"
Great comment. Yes - I think short cyclists are often afraid to go short enough for cranks, and tall cyclists are often afraid to go long enough. I have a 77.5 cm inseam (I’m 5’8”) and use 150s, which is basically the same ratio as you use.
As someone who rides 49CM/XS frames, I always thought it was insane that brands would spec the same size cranks as a medium or even a large. I used to only run 170mm cranks and would constantly deal with knee pain and feeling like there were "dead spots" in the pedal stroke. I'm on 165mm now - which even that small change has been a noticeable improvement. I'm probably going to go even lower to 160mm soon
I ride the same size bike and going to 160's has been the most comfortable for me. I'm tempted to try 150's even.
As a professional bike fitter I agree 100%
Smart people are able to receive new information and change their previous opinions based on new data. Well done.
Ok, lets put that to the test. The earth is not a spinning ball/globe. The earth is a flat stationary plane. This is absolute. Every test and all the evidence show the earth to be stationary and flat, and no test and no evidence shows the earth to be the 100% fake science fiction spinning cartoon ball you have all been indoctrinated to believe in.
So, are you going to receive this truth?
That’s one thing I did when I got into cycling and triathlon. My tri coach said look I’m not gonna lie to you. You are 5’4” non of the big companies make cranks for you. After bike fitment we went with 155mm and boy was that amazing. I run them on all, road, tri and MTB. It’s the first modification i do from now on.
What 155mm brand cranks did you find?
@@thatprcrawlerguy187 also it saves a ton of money by not trying every so called comfortable seat on the market.
@@northkythe probably went with 5dev
The old science was leverage…so leverage, rpms and bike fit must be the elements to that sweet spot
Yup you're short and below average height, so it worked for you. I went from 170 to 172 and it worked better for me (I'm 5'9")
My two best one-day performances ever on the bike came earlier this season on 170mm cranks. Coming from 172.5mm. I'm 6 feet tall. One might argue that the 2.5mm crank length difference is insignificant, but really it's more like 5mm in total diameter. Especially if you raise your saddle accordingly. That marginal difference (for me) allowed me to sustain a more aggressive position on the bike for longer, increased my cadence, and mitigated potential quad cramps during higher efforts 3-4 hours in. No power loss in my sprint either. The only area not so great is climbing out of the saddle.
Would you consider testing the extremes like 155?
@@ISpitHotFire Not if I have to invest in the cranks myself LoL
What's your inseam, mate? Height is irrelevant.
@ No clue, but the overall point is shorter cranks work for me
You guys are way more sensitive than me! Almost 70 years old, been riding bikes starting with those one-piece, forged steel, chromed things that came on Schwinns. What length were those? Rode 170 mm for years until a free crank with 172.5 came around. Couldn't tell any difference and rode MTB's with 175's for years. There's one of those hanging in my shop now that I rode last week. Had some road bikes with 175 mm cranks too. Switch between all of these bikes and don't notice any difference - no knee pains. Same saddle height on all of 'em. I was never fast but just lucky? I have two modern gravel bikes that I ride regularly - couldn't tell you right now what the the crank length on either of them is...but I'd guess 170 mm? IMHO people make a much bigger deal of this than it warrants...kind of like waxing your chain?
key word: trend. I've been doing this for a long time and have gone thru several trends over the years. Pass on changing my bike setup for yet another trend
There are 2 rather obvious advantages for longer cranks:
1. My bike already has “long” 172.5mm crank on the right.
2. My bike already has “long” 172.5mm crank on the left.
Both are rather essential advantages compared to absent “short” cranks from either of my bike’s sides.
That's a strong argument 😈
what are those advantages ?
@@razorree they are completely free, thanks to the fact that they are already there
Ah, you're suggesting the industry is just trying to get everyone to buy buy buy, how very dare you suggest such a thing 😂🤣😆
@@razorreeyes
I've missed these videos! It must be off-season... good to have you back on YT DJ!
10/10, the first original Jordan I bought way back in college
So glad to see these videos are back! Can't wait to hear your latest tire testing results with the race kings and would love to hear your thoughts on all of the available suspensions systems for gravel racing. Thanks!
Whoohoo!! Science based Dylan is back! Thanks for another great video
swapped out the stock 175 to 165 on gravel build, game changer!!!
Glad this is your first video in the off season! I went 5mm shorter about six weeks ago, and dang, for once I am super happy to be on the bandwagon. I am much more comfortable on my primary bike, and I will be converting my other bikes. I wish I had figured this out a long time ago!
Thanks, Dylan, and congrats on 12th overall! I had been wondering as about all I care about is where you finish, other than who won, of course. But winning isn't everything and good for you to be on that circuit and representing for the privateer, sort of the dream for lots of us. 😀
I'm 6' 4" but switched from 175mm to 165mm cranks about 3 years ago so I guess I'm ahead of the curve! I switched after reading the research which affirmed there was no effect on power output but it did help with hip impingement which is something I used to suffer with. I think it has also helped with increasing my cadence slightly where I used to be a bit of a grinder but that might just be because I am getting older, 😁
Other advantages of shorter cranks are reduced chance of pedal strikes and lighter weight.
Guess who’s back, back again.
BHD's Back. Back again.
Yeaahh!! He needs to produce videos regardless of his performance. Even when it's terrible, we still learn from his experiences.
Backwards hat Dylan's back
Tell a friend
Shady’s back, tell a friend ?
I went from 175 to 165 and it really improved my cycling experience. It improved my performance in the drops, and it alleviated post-ride knee and hip soreness.
What is your inseam length?
@ 32”
been riding 140mm cranks for years, my father has been riding 145mm cranks for even longer. he's 5'10 and I'm 6'2. It's funny seeing everyone start using things like forward seat posts, short cranks, aero bars, and narrow bars. all things we used to get laughed at for. fit all comes down to what feels best. right now it's fairly hard to find things that short, hopefully people will start listening and make some shorter cranks.
Did you build these cranks yourself? Which manufacturer even offers such super-short cranks?
@@einundsiebenziger5488 I use origin 8, and box. short cranks made for square taper bottom brackets are relatively available, but for any other BB standard you have to go custom. some brands run you $500-$700+. you can drill holes in pre existing cranks if they're solid and you have the tools to be precise.
Origin8 offers 145mm cranks.
I accidentally went from 165 to 175mm cranks on my Enduro bike, and I became more comfortable.
I destroyed my cranks on a wreck, and asked my LBS to order some new ones. They accidentally ordered the 175's and put them on. After a few pedal strikes I adapted to the longer cranks, I just thought my riding was sloppy. I instantly felt better, but didn't give it a lot of thought.
When I got my first gravel bike, it had 165's and I had knee pain. I sold that one and got another bike that came with 170 and no knee pain.
My new roadie came with 172.5 and no discomfort.
I ride roughly 20 hours a week, I'm not low volume. While not a race, I did go solo for a 100k Fondo last weekend and was first on the course. Yes, solo for the entire 60 miles, I never drafted a single person. So fitness is okay (it wasn't a race of course). I did 130 miles that day.
I'd like to find some short cranks for my 5' tall girlfriend, but at 5'7", I sm sticking with 175 if I'm buying new cranks.
Fun fact: I went to a local, well regarded local fitter a couple years ago. After over 100,000 miles of riding, I thought I had my fit pretty well worked out...and I was right. I basically threw away $400 as all of his recommendations had me in pain. So, maybe I'm an outlier.
Went from 175 mm to 165 mm on TT bike. Helped with breathing, ftp not affected, but I just couldn't put the same power out on the short hills. Split the difference and went to 170 mm. btw, long femurs make you less sensitive to crank length (so my fitter told me) and help with climbing. I live in a hilly area so I'll stick with 175 mm on road and MTB.
So glad you are back. Hope when you are retired from pro cycling you go to grad school and do better research with highly trained subjects. Cheers!
Another advantage of shorter cranks is increased ground clearance. It'll get you a steeper max "pedaling bank angle" during turns. Also nice on rocky terrain.
Yes! Science Dylan is back! Oh how we've missed you.
Now, if only manufactures would be put appropriate length cranks on bikes out of the box . . .
Cranks, stems, bars, saddles, chainrings, cassettes ... in an ideal world all bikes would come with all of these parts configurable, just like they come out of the box without pedals.
I guess you need an ebike then, my large emtb came with 165 and its perfect for me, way better then the 175 on my xc
@georgeorwell7776 now, I just need to convince my wife... 😂
@@georgeorwell7776my 2022 size M giant reign-e came with 160mm cranks, they must have went with it mainly to reduce pedal strikes because of a lower-ish BB height. It feels so good
Dylan Cmon. I can barely source 165mm cranks as it is 😂 (Nice to see you posting)
165 are the first to go in inventory everywhere I look.
Hopefully manufacturers will increase production of shorter cranks
Very nice video!
I went 165 mm the past year, I do not pedal a lot but I preferred them in order to have a winder hip angle and a lower range of motion for touring. Long days on the saddle are better without pain 😅
Finally…been waiting months to hear this voice again
I think you are missing some other advantages of shorter cranks: less toe overlap with the front wheel, also harder to get pedal strikes on corners.
Those differences could also be utilized for different frame geometry. With less toe overlap, you could shorten the wheelbase to give an advantage in cornering. That could be a significant advantage in Cross or crits.
Big advantage for crits, but sometimes in CX you need to put out big torque for short steep sections - long cranks help with that.
@@carlosflanders518 yeah, these power/performance numbers all assume you are in the right gear, which on extreme climbs I almost never am!
I don't think that toe clip overlap is an issue other than for maybe kids and casual cyclists. I'm sure all my bikes overlap but I don't recall ever touching
@@gbshaun It's a major pain when commuting or navigating tight bends at crosswalks. One of my roadbikes has notable overlap - I've raced it for years without a problem but very annoying for training when going slow and manoeuvering.
6’6” years ago went to 190mm cranks. Power up, cadence down, HR down. Life long hip pain gone.
Thank you Sir, I knew this crap would be based on short losers hahaha im gonna go big too
wait 190mm, what did you have before?
I’m 6’7” and switched to 165mm on my mountain bikes. Knee pain gone! Seems like it worth experimenting with… there might not be a best option for a given height.
@@alexander.sollie my system of ‘levers’ works best with the longer cranks.
@@Nilex1994 whatever came on the bike. Then 180’s in the early 90’s.
backwards hat dylan always delivers. im literally crying here :D
Exercise physiologist and bike fitter here. Thanks for pointing out that the answer is always “It depends”. As is with nutrition, training, etc. One point to add as I think cyclists can benefit from zooming out sometimes. Yes this has a net positive reaction on the majority of riders and bike fits. Not that it’s wholly optimal across the board. Cold plunges help almost everyone, but because everyone’s dopamine function is pretty suspect in our polarizing world. Shorter crank arms help, but most cyclists are still hyperoptimizing that context alone. If you happen to learn that you’ll benefit from shorter crank arms than your physics can tolerate, you have some dysfunction. Apart from performance, time under tension, metabolic cost, etc. For human performance you have a limiting factor within your hip or ankle mobility and function. You need to treat a symptom for sure, but if that permits you to disregard all planes of motion, function, and stability you’ll still always be limited. I’m pro short crank arms for the masses and the industry shift, but it shouldn’t let you steer away from optimizing all aspects of the body for the sake of longevity
I have a commute bike with 172.5mm cranks, and my prop road bike has 165mm cranks. And while time on my commute bike is much less i have noticeable knee pain. On my regular road bike i have zero knee issues even after monster rides. Anecdote, absolutely. But in future every bike i have will have 165mm cranks, even as a 192cm rider.
Let’s go! I can finally turn my hat forward.
I'm very pleased for this video, thanks for coming back in this subject.
Also, a big pro of shorter cranks is more ground clearance while cornering
Less pedal strikes if you're a mountain biker too
@@tp3293yeah but I found myself getting locked out in a dead spot while climbing rocky trails more often (less torque to overturn the cranks?). Sometimes it felt like I was climbing using a second gear but at a first gear speed on 165s. Went back to 175s and chugging uphill over rocks feels just more fluid.
Only if you corner with the wrong foot down though? 🤔
@Eirikkinserdal What if i want to accelerate while leaning ? To transfer the weight rear wards, to get more traction and corner even faster
@@Eirikkinserdalor if you need to pedal through the corner
Great to see science-based Dylan back!
As a professional bike fitter in SA; I agree 100%.
We sure have come a long way over the last 25 years on this topic. At 6’1” with relatively short legs and a lot of flexibility I used to run 175s for Mtb and road. I dropped to 172.5 for road and saw zero downsides, then followed with a drop to 170 for mtb and loved it immediately; only benefits perceived. For 2023 I took the leap and went to 170 for the dropbar bike I do everything on, and gave it a good shake. Ultimately, I couldn’t convince myself that 170 worked better for me in any way than 172.5. If anything, I kept thinking I had a bit more weight on my hands than I wanted, and my sweet spot cadence range didn’t seem to jive (I’m an 85rpm guy). I swapped back to 172.5 for 2024, and haven’t looked back. In Oct I rented a Giant TCR while in Portugal, and did about 900km on it in the Algarve. It has 175s, and they felt like crap. Both knees also showed signs of strain here and there. Looking at mainstream 58cm bikes on offer these days, it seems many brands are still into g 175s, which is ridiculous in my view. I can’t see them making sense for anyone under 6’5”. Similarly, 44cm bars. What, really?!
I went from 175mm to 170,im a heavy and lage partypace guy on a ATB and it worked for compfort too❤
To provide an N=1 counter example to your conclusion.
When I was racing on the track (Burnaby Velodrome, 200m) about 10 years ago I quickly found that while I could barely keep up with the "B" group (avg speed 44kmh) on the mandated 88" gearing, I could hang easily with the A group (avg speed 48kmh) if I raced on much larger gearing. Typically 96"-100".
Effectively (as a non-sprinter Time Trialist) I was limited mostly by cadence. an 88" gearing required a much higher cadence (> 110, and as high as 130). The much larger gearing allowed me to keep cadence mostly below 110.
Moving up to 175 mm on my track bike also helped me (although this was subjective). That allowed a larger front ring and a smaller cog, which reduced cadence as well.
None of this helped with sprinting. But when there were B races I could enter that did not have gearing restrictions, I could easily work the front and tire the pack out, reducing their ability to sprint as well, especially in longer points races and point-a-lap races.
I basically did the same research some years ago and found the same thing, and swiftly went from 175 to 170
I am currently building my new Bike up. I bought a 160m Crank because it was 200€ cheaper and thought it was maybe a mistake but ❤ for the Video.😊
The king is back
I went from 172.5 to 167.5 this year. Knee pain went away.
How tall are you
@ 6’0 with a 30-31” inseam
As a fixie nerd I started with 165mm cranks and I love that on my road bikes now and other track bikes. 165mm on my Enve Melee & 167,5mm on SWorks Venge
I have dropped to a 165mm cranks. This was for comfort. It opens up the movement in the legs, and as an older rider - it just makes sense. As for “speed performance” I am still slow! I am just more comfortable.
I am 170cm (~5'7), I switched exactly from 172,5mm down to 165mm. I am a hobbyst, rookie at best, but still could feel the difference. Much-much confortable on longer rides
Ayy! Welcome back! Really enjoyed following your big sugar prep on Strava btw
Been on those 160mm cranks for years. Highly recommend
Tell Felt to release a version of the Breed Carbon in team colors!
Switched from 172.5 to 165 early this summer. Definitely helped reduce hip pain.
Went from 175!to 165 on my main bike. Now when I ride another bike with 175 I get hip pain I never had before.
I've missed these videos -- glad you're back. I most appreciate the thorough analysis (20% of inseam recommendation is for sprinting!) Hey! Even fitness cyclists can be interested in geek.
My main road bike is a 1977 Raleigh Grand Prix, which fits me but, compared to modern bikes, is huge. It came stock with 165mm cranks. I wonder when the industry lost the knowledge that this was an optimal crank length? My theory is that it's like how skinny tires feel fast, so it took a long time to break from that (and lots of folks still haven't). Mashing on a 175mm crank feels like you're really doing some work and probably feels more powerful than a shorter crank, along with bro-science "longer lever means more torque" type thinking, so that's what people were asking for and it became the standard.
Happy to have you back.
I eco all the comments that “you are back” at least for the time being. Missed those kinds of videos. There is plenty of other people out there saying the same. About to give it try, soon.
I was gonna buy 165 cranks anyways for my new, xc bike, because I like them so much on my e enduro, the video is very interesting and makes me get them even quicker.
I very much appeciate your conclusions. As unclear as the science has been for decades, your summary agrees very well with my anecdotal observations over the last 45 years and what has continually frustrated me about the bike industry in this regard since the 80's when we moved from 165 and 170 cranks as standard along with 38 cm handlebars. Thx.
I'm 6'1" and went to 165mm cranks on my 1BY MTB. It is the bike I ride the most these days. Faster cadence at low speeds helps with balance on features and with missing obstacles. My Salsa came with a 30T (too low) and I put a 34T oval on it. I'm absolutely going to convert all of my bikes to 165's. I'm faster than most of the people I ride with anyway, and I do have occasional knee issues. Seat comfort, with less rocking seems better too.
I also moved my shoes forward a bit after watching a video on avoiding the old "ball of foot" suggestion. Then I put a cane creek stem on my gravel bike, and that was a game changer too! Just go ride what you have. ;)
Thanks for supporting my confirmation bias 😁 I'm slightly taller than most (186cm or 73") and I've gone to 170mm cranks on all my bikes. I'm not convinced about sprint performance, but holding an Aero position in a breakaway is much easier.
Glad to see ya back 😁~ It's been too long.....
Good analysis. I like how you used research papers. Now the industry needs to catch up because I’ve found it hard to find shorter cranks. I went from 172.5 to 165, then tried cheap 160s on a klunker bike and it was even better. I now have an even cheaper set of 152mm sitting in a box I want to try. I’m 5’8” average proportions 31” inseam. My hips feel better, knees much better and I feel like higher cadence spinning is easier. Wish I did this decades ago - I’m old and I’d recommend it to younger people.
Glad science Dylan is back ❤
Awesome Dylan! Happy to see you back, keep up the great interesting content, Thanks Bro!
5’7”. Rode 175 for decades. Went to 165 a couple years ago and wish I would’ve done it a long time ago. So much more comfortable and it feels easier to generate power.
I switched to 165mm cranks 6 years ago. I can definitely push the crank over the top better with them. I use to be able to get 165s dirt cheap. Now I can’t even find them
Great video. I've been on 175 cranks for years, had several bike fits over that time and never has the fitter told me to size down. For reference I have a 33 inch inseam. One thing I have done is gone to zero offset seat post which effectively steepens the seat tube. This allows the rider to get lower without decreasing the angle at the hips. It has worked for me. That said I have experimented with shorter cranks. I loved what it did for my cadence. But I hated what it did to my center of mass. When I went shorter I raised the saddle to maintain the knee angle at the bottom of the stroke. I did not like the feeling of sitting higher, especially off-road. I consider myself lucky in that I can ride with the cranks spec'd by bike companies. But I agree that shorter is likely the better call for most riders.
well made video. thanks. I only hate it that people only follows what the Pros are doing. long time ago my trainer wanted for us to use shorter cranks, but some where arguing that no high performance athletes were using them.
I switched to 165mm on my mtb about 7 years ago and never looked back. I got a gravel bike at the beginning of the year and it too came stocked with 172.5mm cranks. Switched over to 165mm about 4 months ago and will never go back to a longer set. Just feels better!
On more than a few occasions over the many years I have been selling bikes, I have recommended shorter cranks to customers with knee pain. In every case they had a reduction in pain. DT
Hi Dylan I suggest that out of saddle climbing is benefited by longer cranks, as torque is linearly related to crank length. So for the same applied power, your applied torque will increase. 175mm cranks will increase torque 6% over 165mm. That's obviously a significant advantage on climbs.
36.5 inch inseam here. 20% is 185mm cranks for me. I currently run 180mm cranks.
Great stuff. This is a splendid channel!
Perfectly happy with my 175 mm, will not change
GREAT to have science Dylan back!!
What about the aero penalty for having to raise the saddle as well as handle bars when going shorter cranks?
Also possible aero penalty of higher cadence?
BTW I went lower in crank length
Actually it’s more important to match to tibia length instead of leg length
There is no aero penalty because you are now able to bend more at the hips and get your body into a lower more aero position, this might not apply if you're one of those riders I see out there riding around upright on the hoods (most of them) but for us that like to ride in an aero position it really is the main benefit of going down in crank length. You put the seat up to compensate for the higher position of the lower pedal so that relationship stays the same, no aero loss there, but your total height is reduced because you can lower your upper body to be more aero, usually you don't even need to raise the handle bars and definitely not the same as the amount you have to raise your saddle. My cadence varies all the time, I've never considered it to be an aero penalty at higher cadences. My range is between 60-120rpm when riding a single speed. On a geared bike I just ride which ever cadence feels comfortable, I don't try to maintain any mythical optimal cadence and the range is wide.
Christmas is here!
You forgot that shorter cranks can be lighter! :) Add that to the advantages column. Oh, and less pedal strikes too.