0100 here in Spain. The missus upstairs probably waiting for me to come up for a jangle........she can wait. Stanbury just dropped new content. Kettle on the boil. Im opening the good biscuits. What a time to be alive.

I've ridden a variety of crank lengths in 56 years of cycling - 165s, 170s, 172.5s, 170 on one side and 175 on the other (long story) - and have never noticed any significant difference. I switched from 172.5s to 165s about 12 years ago in hopes that it would help with some knee problems. It didn't, but I've stuck with the 165s because there was no reason to change again. By the way, what eventually did make my knees better was strength training, specifically squats and deadlifts.

that saddle really steals the show

As someone who voids their bike's warranty just by sitting on it, I really appreciate the point about soft tissue opposition. It's something I rarely see a lot of discussion about on these sort of bike fit videos, but it's really helpful when it's included, even when it's not the main point of the video.

He really did say..."if you're really short down below"

You and other channels discussed this quite a few times since 4 years ago. I'm surprised that bike manufacturers still don't use shorter crank arms for their 2XS and XS bikes. If any change, it's a very reluctant one. I'm 167 and use 160 for both road and e-gravel (which has aero bars too).

Going from 172.5 to 165s changed my riding life. I actually did it on a whim after watching a few Neil videos. Turned out my a-symmetry and right lower backcpain was caused by a very stiff left hip. The pain literally went over night.

Fantastic overview! Shame it's so inconvenient and often expensive to change cranks. Should be able to choose when you purchase the bike.

I've moved from 160 to a 140 crank and have loved it. Being 5'7 with a short inseam, I have loved the feeling of the cranks. Everything feels so much better.

I think you missed one very important category and it's not just riders on the tall or short extreme, it's the balance between leg length / inseam and your overall height. More like the distribution between your top and lower half. For instance, I am 5'9, 185 lbs, quite lean, no gut but my cycling inseam is 34.25 inches, very short torso, and huge femurs. Hip mobility is great, I can squat to the floor w/ flat feet and be totally comfortable but this is because my knees go way outside my torso. See Squat University's videos on squat stance for different physiology. This is exactly the same for cycling. Long or normal cranks mean my knees will be hitting me chest at a normal saddle height (I'm at 740). 165s were a drastic improvement from 175 and 170s but was still having issues w/ low back and hip flexor pain. Funny enough, this morning I just installed 160s on my bike, it feels INFINITELY better. I immediately was able to raise my saddle 10mm more, I feel way more stable, it's insane how much better it feels. Wish I woulda done it a few years ago.

I have a 165mm crank and it's great. I got it purely so I could raise my seat height to make my bike look pro 😅

Anatomy refers to the internal and external structures of the body and their physical relationships, whereas physiology refers to the study of the functions of those structures your amazing knowledge of our anatomy and our physiology and how these interact with each other Neill your a one off and that's for sure i never met anyone with greater insight than you have in this area and how you make corrections for our shortcomings WOW.Thank you loved the video Sir.

Purely from mechanical perspective, the produced power (P) is equal to torque (M) multiplied by angular speed (ω): P = M * ω = F * l * ω where "l" is lever length. Now, lever length is not exactly equal to your crank length, but it is very much proportional to it. So, if you go for shorter cranks (l decreases), to produce the same power, you either need to push the pedals harder (increase F) or spin faster (increase ω).

if anyonre don't have physical limitations, than the most correct way to choose the cranks length is according to length of the legs. but not only inseam matters. it is important to take in account the ratio of hip and shim. if hip longer than shim it better proceed with longer cranks. if shim longer than hip it is better to choose shorter cranks. the ratio of hip to shim crucially influence on cranks length

I’m a big rider at 6 foot 230lbs and moved to 170 cranks and felt an amazing improvement. Currently building a gravel bike with 167.5 cranks and looking forward to it.

I have some hip flexor impingement , which resulted in a recent bike fit dropping the crank length from 172.5 to 165 . The improvement felt from this adjustment and other tweaks was pretty immediate. However, the major impediment to moving to this set-up is now actually getting 165 mm cranks that are compatible with the various BB set-ups. Here in Melbourne and most likely across Australia currently acquiring cranks or crank-sets of this length is near impossible. Perhaps the shorter cranks and their benefits is an aspect now being picked up by bike fitters across the sector and hence this dearth in being able to acquire these length of cranks . The fact you can't get them is obviously relieving riders' discomfort, as you can't get out and ride

Excellent disposition on crank length! Really learned a lot

I use 160mm cranks and I'm thinking about going to 155's or even 150's. Going from 170's to 160's made a huge difference in comfort. I have hip impingement and going to shorter cranks really helps, as was said in this video. Another thing that has really helped is using Favero Assioma Dui Shi power meter pedals with a wider q-factor, and also using pedal extenders when I'm not using those pedals. Pushing out the foot stance wider means much better knee tracking and much less stress on the knees when you have hip impingement. I want to add that hip impingement is often just how your hips are built -- there's no flexibility training you can do to improve it, for many of us.

Croder makes 140mm cranks that are designed around a 24mm shimano style spindle. Got a set for my 9 year old daughter’s 1st road bike, fits BB386Evo with spindle adapters.

I tried going from 175 to 170, didn't work for me. I simply didn't enjoy riding with shorter cranks. I'm glad I tried it to put the question to rest for myself. I imagine for some people it would be a game changer though because the difference was surprisingly vast.

Forever hip problems here, hips at about 45 like you show. Looking into getting some 165mm cranks right now, might start with 105 set to try, think the Ultegra and Dura Ace older cranks are on recall..

I had hip impingement and was having hip pain with 175mm crankarms on my mountain bike. I got 165s and the pain is completely gone. I'm also more of a cardiovascular rider and like to spin higher cadences, so its a win-win for me.

Neil, would be interesting to know how your saddle height compares to the heights “ recommended” by the various more traditional methods!

I'm surprised that none of the videos about shorter cranks makes any explicit mention of the reduction in leverage they give, although this was hinted at in this one at the end of this one. Going from a 172.5 to a 165 crank is about a 4.5% reduction in applied torque for the same force. and as power = torque*angular velocity, this means less power for the same cadence. Has anyone looked into whether there is any advantage in changing the chain ring tooth count with shorter cranks to compensate for the loss of leverage? You could compensate for the estimated reduction in torque by having 2 fewer teeth on the chain ring.

I’m on 155 crank arm since I’m not a tall guy. It definitely helps during long-distance, and I just need to train more on cardio; when speed is required, crank up the cadence before shifting to a smaller cog.

I recently went to 160 cranks after staying with 172.5 for the last 10+ years along with raising my saddle by 50mmish, and the difference is amazing. I don't like to grind at low cadence so I also went from 52/36 to 50/34 on my crankset, and I can hold the rpm that is comfortable, along with making the power I have. All of this has led to an improvement of approximately 25w alone. On my first day wit the new fit and the new crankset I matched my ftp after being off the bike for most of a three-month period (rode once a week) and can hold those 25w at the same heart rate as before and I don't feel as tired as before. The better aero position is also a huge benefit as all of this has shown an almost 2 mph speed increase on my solo rides for a given effort. I have been talking to the guys on my team about it and I have convinced several to 1.) get a good fit, but 2.) shift to smaller crank length, especially those who are built similarly to me.

I'm 6'2 with really long femurs running 175mm cranks. But also I tend to spin high cadence 95+ for threshold and definitely a more aerobic kind of rider. So a bit conflicted maybe I'll try 170mm cranks some day.

Love your show and it has helped me a lot. Q: When I switch from 172.5 to 170mm crank I feel pain in my right hip flexor. I have adjusted the saddle height accordingly.

Very informative discussion thanks. Another comment alluded to taking into account the relative length of the upper and lower leg bones. I’d be really interested to hear whether that’s something to consider. Unless the ratio is very unusual, would that really be a factor in bike fitting?

Hi Neill! I was just wondering how do you rate the Bontrager Montrose saddles? I am riding a SMP Composite but I am always on the lookout for an improvement........ Many thanks.

I bought a used Trek Domane AL disc. It had a 170mm on the right and and 175mm on the left. I did not notice this or think to look for this. When changing out pedals, I did realize the difference. After a year I had not notice any hip or knee pain. Should I immediately change one or the other to match. Thanks

Tried shorter cranks and had issues recovering post ride with more avg force on the pedals (at sub-optimal cadence I suppose). Went back to 175mm as I have long legs/short torso at 6’1” and reasonably good mobility.

👍 Because I'm old, my height today is 166 cm..😁 I've always ridden with 172.5 mm cranks.. I've sometimes tried shorter ones but they feel so strange.. besides, quality carbon fiber shorter cranks cost an awful lot.. More videos could be made for undersized people (under 165 cm 😁), adjusting the bike.

Thanks for talking about the other side of crank length(all bikes 172.5).... I've been thinking for a while about going to shorter and I may still go there(but maybe not 165 short), but as a B- .. C+ aging sprinter who only 'races' crits where do you change from relying on neuromuscular to endurance

I love shorter cranks. I switched from 175mm to 170mm for this year road season and Iam 6foot4 and they are amazing for me. For solo breakaways in road race they are amazing. I can ride in fully aero position on a road bike for hours and hours witch has masive aero benefits for me. Thanks for amazing video as always, guys. PS: love "eaglebeak" saddle :)

Does Neill uses any wedging in his bikefits like Steve Hogg? Thanks for an answer!!!!

My sit height is 64cm and i’ve benefited from using 155 crank length. I’ve tried both road (straight arm) & mtb (bent arm) 160 crank length and still prefer 155 road crank. I’m this calculation as gauge: a) 163(height) x 0.95 = 154.85 b) 1.25 x 72(inseam) + 65 = 90 + 65 = 155

Really info like it lots, will I’ll have to try 165s so how it goes ✌🏾👌🏾

I have a super short (730mm) inseam at 178cm height but am built for short neuromuscular efforts. I have good mobility and don't have the spare tire around the gut - what would be my best call?

Hi Neill, Do you think using shorter cranks can also help fill out the dead zone in pedalling ? Im 173 cm in height and i use 170mm crank on my Aero Bike while 172 mm on my Climbing Bike. I have a huge dead zone from 8 o'clock position to 12 o'clock and would like to know if using shorter cranks would somewhat help fill this up. FYI, I dont have any hip flex issues and my saddle height is 695. What size crank would you recommend to get a better pedal phase and do you think using shorter crank would affect climbing efficiency ?

I'm using a 172.5mm on my outdoor race bike, and 165cm on my track bike. Initially I set my saddle on my track bike on the same height (measured from the center of the BB) compared to my outdoor bike. But recently I put my saddle 7.5mm higher on my track bike, which allows me to stretch my legs/knees as much as on the race bike. Does that makes sense? Or should I keep the distance saddle-BBcenter as common reference?

My Gravel bike came with GRX 172,5 cranks from the manufacturer. At longer rides I feel very uncomfortable knee pain which I didn’t experience with my trekking bike with 170 cranks. Unfortunately, the smallest GRX 600 cranks available are 170s. Do you think going down by 2,5 mm from 172.5 to 170 will produce a noticeable difference for the costs? I am 178 cm tall with long legs and an 87 cm inseam. Or can you recommend any cranks other than from the Shimano GRX 600 series that are available with shorter cranks and would be compatible with a a GRX 810/600 2x11 set?

I just laid flat on the ground to test out criteria #1. My thigh contacts my lower rib cage and stops there. At that point, my knee is quite a bit away from my chest (20 cm'ish). I look nothing like Neil who somehow is able to have his leg, from hip to knee, touching his chest. Have I failed the test?

Im 6'1". Always used 175 mtb 172.5 road. Replacing my road crankset with a 170, mainly because there wasnt a 172.5 option but now Im interested to see how it will feel.

165mm cranks allowed me to ride all day vs an hour or two due to back pain pain from my herniated L4-L5 and L5-S1 discs.

A question for neill: Does shorter crank exaggerate bike fitting issues? My leg discrepancy is more obvious as my left quad always start to hurt more than the right one, especially in TT position.

I have 688mm seat height to bottom bracket, and hip impingement currently running 170mm. Would 165mm be better for me?

Do you adjust the seat according to mm from the crank change? If I go from 175 to 170, do I have to up my seat by 5mm??

What I find amazing is how bad the LBS is at fitting a bike to someone. They sell someone a bike that is clearly not fit properly to the rider. The rider has a few rides and stops due to poor fit. You could spend 3K on a poorly fit bike and then only ride a few times then ditch it. I think anyone who is serious about riding should be fit BEFORE buying a bike. Go to a real fitter. Get set up on a fit bike. Get all these parameters down first, then get the bike that fits you properly. It will save you thousands of dollars, a whole bunch of pain, and you will be much happier! This guy is phenomenal!

I’ve been experimenting with 145s, down from 170 and I’m seeing tons of benefits and no downside (apart from a frame with a bottom bracket that’s not at the optimum height).

I'm 2,02m. I'm more of a lower cadence rider. My muscles can put high force over a long time, but as soon as I go for high cadence they start burning super fast. On my older MTB I have 180mm shimano deore cranks, from the time where shimano had a series for taller riders. Everytime I step from my road bike (175mm) to my MTB, the crank length feels so much better, but I still feel, like it isn't enough. Therefore I have been playing with the thought of getting cranks manufactured. That would be a lot of money. So, how do I know if it's a good idea or not and for what length should I look? How can I calculate that to at least get an estimate?

I'm 5'4" using 170mm on my TCR and 165mm on my Canyon and SL8. I noticed 165mm is comfy enough during long rides.

I concur. 3 ticks out of 5 for me. I swapped cranks from 175mm down to 170mm recently and feel much better.

I've got zero hip flection issues, but bringing the knee near or past 90° gives massive recovery pain in ligaments. Short cranks help but I need more help

I went from 175 to 165 on my mtb and all the reasons were correct...hip issues disappeared completely...my sports physician couldn't fix it but my bike fitter did

How tall is Neil ? I’d love to know in relation to his saddle height. Another great video, love this .

Another bonus that comes up less - I switched to 165mm on the road for less hip impingement/better ergonomics. I then switched to 165mm of road and it’s been a revelation. I don’t feel like I have less torque and I have almost no pedal strikes now, all while keep my crank length constant across my bikes now. It has turned out to be a win/win/win situation (ergonomics/consistency/fewer pedal strikes).

Seat height is 690 using 160 cranks, love them!

When I did the knee bend test my left leg was aboout 30-40 degrees, but the muscle was tight and stopped me moving anymore. My right was better, without the muscle stiffness. I will try shorter cranks.

Soft Tissue Opposition (STO) lol As an older rider (60 y/o) I certainly suffer from this condition. It amazes me on how the industry arives at a standard. Given this discussion I wonder if the standard set-up for the average rider should be with 165's. I would venture to say the average rider would never think twice about having a shorter crank and would just ride it the way the bike shop sold it. However, they would have a much better physiological experience. Thanks for sharing Matt Hudson Valley, NY

WoW. Gotta save some money and make my way down have a fitting. And a holiday ride

178cm(5'10'') here with long legs and long legs and flexible pelvis(so I sit high and reach far down), and I've gone to 160mm cranks to alleviate hip impingement. I actually had 155s early on, but then they got stuck to an old frame in a freak accident, and for some reason I didn't bother getting the aftermarket cranks again. Now I just need a new frame or fork, because my handlebars are too low(tolerable but not optimal) xD

Could you talk about the effect of crank length and the relationship of the knee angle at TDC and BDC. I’m 77 and use 165 cranks with old degenerative knee issues. My gravel bike has 170 cranks and my knees get sore after a longish 1-2 hr ride but not on the 165,s.

I did a fitting recently. Im 178cm tall and was given a seat height if 715mm and 165mm cranks. Im assuming that Cam and myself have the same "short leg issue" and I too have a minor hip impingement and he'd have about the same saddle height as myself. (His falath Evo is setup almost identical to mine.) How tall are you Neil to have a "regular" seat height of 750mm+? Im starting to feel like a smurf.

I have an 98cm inseam, total height of 191cm. I was on 185mm cranks, 180s, 175s, 170s, 172,5s and recently on 177,5mm cranks. I was constantly fidling with my position, especially seat height. Now I thought, I might just give it a try and install 165s. They feel way more comfortable when riding. As if the whole fit is more "relaxed". No more fidling. Let's see how it will turn out in the long term.

165s are the bomb! And I’m average height. I went from 172.5mm and tried 165s because I had some old cranks from a vintage bike project I had lying around. Wow! I noticed a 3 watt increase in power on a long climb I do on occasion. Maybe it was placebo. I don’t know. We might be onto something with these short cranks. Maybe we can even go shorter and get more power!

I’m 167cm and recently started using 160mm cranks, down from 170mm. I definitely feel like I’m pedalling underneath myself. I didn’t notice much increase in cadence though

Thanks for the info always very informative!!! Have just gone to 155mm having a height of 5'-8'' and only 30in inseam man can i get the cadence up now !!!🙂

I use short cranks because I've got long legs and a barrel chest so I hit my chest with my knees (still happens in the drops)

there was no mention of tall riders. my saddle height is 825mm, and i use 175mm crank, is that ideal or should i try shorter?

im 5'4" height..what is the recommended Crank Length Thankzz🥰

Long crank arms, push the lifting leg higher, the elasticity of muscles and tendons work against the lifting leg, making the pushing leg work harder. Less lift less work. Smaller circles, less work.

Love that beautiful looking saddle in the background! Just gone to an SMP Nymber - love it!

Thanks for the interesting content, you have been advocating shorter cranks for a while and I understand the advantages. But aren't there advantages and good arguments for longer cranks, as well?? Especially for taller people (like 1.95m tall and 96cm inseam)?

Any changes needed to the chainring size after adjusting the crank size?

At which height or leg length would bike fitters concede 175mm would be for them? If a rider has an inseam of say nearly a metre i'm guessing 175mm comes into play.

I have a stride length of 100cm and since I've been using 180mm cranks I've had significantly fewer problems with my knees - I think there's too much talk about short cyclists - or short-legged people - but from 90cm it gets really long and I'm only 190cm tall There are a lot of great people out there...

So you're saying myself as a 60kg 5'7" bloke (seat height at ~675mm) with a tendency for riding at high cadence I should really be thinking about 165mm cranks rather than the 172.5mm (that came on the secondhand bike). My summer bike has 170mm cranks and i can't say I notice any difference.

Thanks for sharing! I'm around 172cm tall. Would using a 165mm crank help me (or anyone my height) climb efficiently on ascents with an average gradient of 5% and max of 22%? Thanks in advance

I've got major hip flexion issues AND a fair bit of soft tissue opposition. When I do a the knee to the chest test I get to about 45 degrees and both the hip and the sunken chest tell me that's enough of that rubbish.

how are you measuring seat height? From the middle of the bottom bracket to the top of seat? I am 170 cm height / 75 cm inseam. what crank length do you recommend? 155mm? currently on 172mm with some knee pain from motorcycle accident.

"soft tissue limitation", "spare tire around the middle" cracks me up 😂

Why shorten cranks? Is it simple? I do not think so.. According to physic the torque required to drive the bike working on the circle equals power * power radius length. So when crank length is shortened to get the same torque the power must be higher - power means your muscles in this case. It means you will have to reduce gearing when uphill - sometimes push the bike if torque you can generate is not enough. You can change front gears for smaller but in the result you will get less efficient and slower machine - you must work on higher cadence all the time. Yest you can ride like that but everybody has limited cadence value. Of course for someone who has short legs shorter crank is better but the reason is pedaling kinematics - range of work of knee and hip joints changes a lot. so finding the optimal crank length depends from individual rider features.

160mm cranks here. Truly changed everything about how comfortable I am on the bike.

I'd love to know if Neil finds climbing a bit tougher on short cranks because of lower torque = more leg force. How pronounced is this? I'm considering going from 170 to 165mms

I’m 185.42cm but have long legs at 91.44cm what crank length would you suggest for me q

I'm not that short. at least I don't think i am. 170cm with short legs and went down 160mm cranks and it's been a gamechanger.

Could someone explain the measurements of saddle height he refers to?

Crank length change in 2 bikes for me this year. TT 165 from 170 (recently tried 155mm but didn’t like the loss of torque) & road bike 170 from 175mm. 6ft 1 inch, 73kgs reasonable mobility but I am aging….hit 42 later this year 😢

if i 5,8 tall so 165 better or 160 for asia body type ?

The main disadvantage is that you have to raise your saddle. So you have to bend down more. I recently swapped from 175 to 172.5 and reached the limit of my neck flexibility by raising the saddle by 2.5 mm. Results: neck pain, tense shoulders, back pain, numb hands, numb feet, hurting bum. And a bit higher cadence overall, but at the expense of bad fitting gears (either too high or too low cadences for my taste and body). So back I am to 175. - Much better is losing some fat from the safety tire, especially the visceral fat. Hip flex gets easier, breathing is much improved, heart rate goes down. Lost 4 kg, heart rate down by 5 to 6 beats. (I’m 1.88cm/6"2', 100kg, saddle height 800 mm, more grinder than spinner - if all that’s of interest to anybody.)

Anybody get numb feet after they’ve stopped cycling? Could it be one specific thing or is it like opening a can of worms trying to narrow it down. A bike fit is on the agenda but I’m a month or 2 away from being in a position to get one. Cheers for any replies in advance

but but but.... is the force not roughly the same with shorter cranks at a higher cadence?

What about top end speed? With the higher cadence, will I spin out faster when I am going fast downhill?

What would you consider "shorter cranks"? E.g. I'm using 175's currently and think of switching to 170 due to the hip flexibility. I'm 1.91m, 77kg (sorry metric ;)

For a bike fit specialist, the saddle on that bike behind him looks to be way too far forward...

Had this topic on my plate for quite some time and got my new bike with 165mm half a year ago. Went to a bike fit a week ago and was told after 5min that I apparently need even shorter ones and was sent home. Currently waiting for 155mm ones to arrive. I am very curious how the 155mm will feel.

I’m pretty sure we have it all wrong and that riders with longer feet should actually ride shorter cranks. Sort of like saddle width, smaller riders normally go for 155mm and larger blokes tend to settle on a 145mm seat

Insightful analysis. But gosh, the old standby, 170mm, is right between 175 and 165. How about that?

Adam Hansen - used 180mm cranks (max allowed?) at 1.86m/6'1" tall. Crazy handlebar drop/extension, and record for most consecutive Grand Tours. (I only bring this up for shits and giggles)