I had a hip replacement about 15 years ago (I am now 59), just last year I started to hear about the think about crank length and moved from a 172.5 to a 165 crank. The change has been awesome. My general riding is much more comfortable and I have no residual hip discomfort from riding (which I had previously). What is infuriating is that I have had many bike fitting sessions through the years and the idea of crank length was never discussed, even though my hip issues were always known. At one point (post hip replacement), I was on a 175 crank and suffering hip pain and not once did the bike fitter ever discuss crank length.
Interesting. After a crash, I had a total hip replacement 12 years ago at age 54. I've never experienced any pain or reduced range of motion, still using 175mm cranks. At 66, I'm still competing on road races as long as 90 miles.
Excellent video, thank you James and team. One small remark is that the background music is a little too loud (I would personally remove it altogether but at least reducing the volume would help focus better). Thank you again for the great work
Riding 160mm as a 1.75m person with a gut and my power numbers were highest on a 160, did try down to 150. Matt Appleman has sold me two sets and with OEMs now making 160 and shorter we have plenty of options. I have found the opposite of what James said, for me,I feel more in the middle of the bike when climbing stood up. I get too far over the front with a longer crank (170) when standing climbing. We are all individuals :)
I have been riding with 170mm cranks since they came on my size 50 Domane. After watching numerous videos I decided to try 165mm cranks. Even though I had to get the power meter too (SRAM Rival) I decided to go ahead with the change especially given the fact I am 5' 3" with an inseam of 750mm and felt there was only an up side in my situation. I ordered them Monday and had them installed yesterday as well as having another fit to make sure things were in line with where they should be. Just got back from my first ride with them. A huge success! This season I was in the mid 16's on most rides with an occasional low to mid 17 mixed in. I hit a PR today with an average speed of 18.8 mph on a 55 mile ride with 2500 feet of climbing. Pretty excited with the ride. I definately noticed things during the ride that I liked. First of all, I was able to keep pace with the other riders better on long gradual climbs spinning faster, which allowed me to switch into a harder gear more efficiently. I was also able to close any seperation much faster this way. Normally I am towards the back in this situation on group rides but today I kept pace better. Climbing was easier as I didn't feel like I had to "get over the top" of my pedal stroke in comparison to previous rides. Even though I didn't have knee pain with the 170's it was more comfortable on my knees during. Felt things more in the quads which I prefer. I learned I would rather spin up a bit to propel myself forward instead of powering up with my legs. Cardio over muscle fatigue. I did have to make minor adjustments at the beginning of the ride based on the fit but once I did everything felt great. Because we raised the seat without raising the bars I can also flatten my back and get more aero in both the drops and the hoods. Very glad I experimented with shorter cranks. Already sold my 170mm crank set. For me it was a win. Who knows. I may try 160mm cranks next season but I felt dropping from 170 to 160 off the bat was a bit much.
The fit rule is simple: if you can't pedal smoothly through the top of your pedal stroke when riding in the drops, you can benefit from shorter cranks. And cranks are rarely too short but often too long. I have a 32" inseam and ride 150mm cranks.
I'm 5'8" para-cyclist, (1 leg) and shorter cranks have been awesome! I'm down to 160mm crank on my road bike and 155mm on the MTB. James is spot on about fatigue and shorter cranks. Much easier to spin more (in a lower gear) and for longer with the short cranks compared to the 172.5 that the road bike came with. The MTB is just a spin machine now, not fast but not much stopping it.
I also ride with one leg and haven’t really tried smaller cranks beyond 175 to 172.5. Have you tried oval chainrings? I’ve wondered if they’d help with my, and I assume your, power distribution
My personal experience re: not having a long inseam, yet not being short. A larger bike, with shorter cranks allows me to get the saddle height optimal, and keep the fit reasonable. Much smoother, better on my hips, and a not too small frame that would put me in an overly aggressive position. With the somewhat loss of torque due to the shorter cranks, I've changed my gearing to fit. Personally, I think crank length is perhaps the most important factor re: bike fit, as it greatly affects your position on the bike.
I'm so psyched you have your own channel now! I've learned so much over the past few years. Your videos inspired me to book a fit with an IBFI fitter. Most comfortable bike I've ever ridden! I'd LOVE to see a video about the differences between gravel and road fitting. In particular, I'm interested in how local terrain impacts fit. Anecdotally it would seem that reach is impacted by the class of gravel you're on. I live in New England. 80 to 120 feet per mile average elevation is not uncommon. Also, unmaintained roads are common. Lots of Class 3+ stuff over here. Due to the elevation we get a lot of chunky conditions due to erosion. I think the reach on the bike I bought is too long. It felt great on a test ride, but that was 2000+ miles of gravel prior, when my only other experience was 40 years of being a roadie. It's a Trek Checkpoint (the frame my fitter selected turned out to be a 52 cm H1.5 Trek Emonda). I ended up lobbing off 1.5 cm from the front with a shorter stem and shorter reach bars, and probably 1 cm from the back by running my cleats as midsole as possible on Lake MX238s, thus bringing the saddle forward a bit. So it's workable now, but I still feel like another 1 to 1.5 cm needs to come off of that bike in order to handle long chunkier days. That said... I just did some gravel riding in Eastern Ontario. FLAT AS A PANCAKE and mile after mile of perfectly maintained hero gravel. In those conditions, the Checkpoint is absolutely brilliant. Anyhow, I'd really be curious to hear your take on gravel geometries and what you need to consider, especially if you're a roadie. Despite how popular gravel has become, I find there to be a knowledge gap amongst the local fitters WRT gravel geometry.
I'm 164cm tall and a couple of years ago started to get a bit of knee pain after lots of cycling (ie daily rides) and nearly all my bikes were 170mm cranks (except mtb at 175mm) but I realised that on the newest bike I had (thankyou Wiggle and Vitus) with 165mm cranks I had no knee pain. Since then I have converted to 165mm or less with the shortest at 150mm with no obvious detriment and possibly the optimum at 160mm. Obviously everyone is different but I just wish it would have been a bit easier to try out shorter lengths a few years ago! Thankyou Shimano for now going down to 160mm and thankyou to Rotor for going even lower!
Hi James, I really love your content one day I will come to the uk and get a fit. At the moment I am looking for a more comfortable bike. I still have to decide between two sizes. I could either get a small frame which would result in a same stack figure as my current setup but also 16mm less reach. On the other hand I could take a medium which would result in 23mm more stack and 13mm less reach. The main downside of the medium frame is that it comes with a longer cockpit than my current setup. So the effective reach would be roughly the same. My main goal is the reduce pressure in my hands. Keep up the great work! All the best, David
I do think we need to clear both the knee and the hip when testing crank length. As important as it is to not go beyond safe hip flexion it is also equally important to not go beyond safe knee flexion to prevent things like chondromalacia/quadriceps tendinosis/patellar tendinosis. Its important to both clear the knee and hip markers.
Loving the content! The downside of being tall is I always get super wide handlebars and 175 cranks. The handlebars are easy to change but the cranks not so much!!
5’3 and been riding with 170mm cranks for years. I’ve had several bike fits and each time I’ve compared of saddle issues (one side only) was always either told to ride more or that I didn’t have the right saddle. Finally riding with 165mm cranks and that small change has made a huge difference.
@@Cal906lil I'm surprised you don't have issues with toe overlap if you have 700c wheels. I would definitely be looking at dropping cranks ength and raising the saddle slightly. And trying a different bike fitter!
Maybe I'll try shorter cranks at some point. I'm ~5'3" too, and on the normal 172.5mm cranks (pretty sure). I don't notice a major problem right now, but perhaps it is worth considering for my longevity as a cyclist. I do have toe-overlap trouble on my road bike, but only while in the city going slow at stop lights - like needing to make a slow turn after a stop. If I have the speed to lean into a turn, it isn't an issue. On my commuter bike it rarely is trouble, as she's longer anyway.
I started riding 165s on my mtb years back to help with pedal strikes in rough terrain, gradually swapped every bike to 165s, now running 160s and 155s on a couple of bikes with equal success. Just feels so much more comfortable and less fatiguing on long distances.
Traditionally, 6 1/2" ( 165 mm ) were for the velodrome. 6 3/4" ( 170 mm ) were for the road & 7" ( 175 mm ) were for touring. An experienced cyclist can mix 170 and 175. 6 1/4" ( 160 mm ) were small lady's cranks. 6" ( 150 mm ) were really small riders & juniors. 5" ( 130 mm ) were 'enfants'. There is a formula which involves a percentage of the 'hip height'. The centre of your hip ball joint from the floor.
There was a time when anyone under five foot eight was told to use 170. Anyone over six foot was put on 175. In between it was 172.5. Tall and short people were told they'd get used to it while the average height crowd never stopped discussing which length to go for. Before that TA in the past had all the lengths from 150-185. Comparing running stride of tall and short runners, tall runners have a longer stride length, but not proportionately longer. Short runners have a shorter stride length, but not proportionately shorter. A way to work out a good crank length is to calibrate at 172.5 for five foot ten and add or subtract half of the percentage leg length difference as the legs get longer or shorter. For legs ten percent longer use five percent longer cranks. For legs ten percent shorter use five percent shorter cranks, etc.
It's good to consider all these things, new technology gives better ways to improve riders comfort and efficiency. But what happens if you change your shoes, or pedals, or both? A few mm could be taken up by sole or pedal thickness and then you're back to square one. I don't know I'm just a nobody but I'm always interested.
Never had an issue with crank lengths 170-175 just work. (I could see 170 as better for TT position) Freaking bar widths grr. Modern bikes are always too wide. I ride traditional french, fit flat top tube bikes 61cm to 25in size.
I switched from 172 to 165 and wow what a difference it made. So much easier to get over the top of the pedal stroke and get the power down. Noticed it most when climbing.
I bought a new bike online a few months ago and probably made the mistake of buying a size too large, because the small had a 165mm crank and I thought “wow that’s ridiculous”. Wish I would have watched this video first!
@@tkbuz frame size and crank length don't have to go together. I have a medium frame, but switched to shorter cranks. My upper body is long and my legs short. I had a bike fit and shorter cranks were the recommendation.
Been waiting for this vid from James. After he made this comment about crank length on Francis' channel a year or so ago I wanted to know if he'd had a change of mind with the new push to shorter cranks. Also, on the topic of cranks, I bought my average height 10YO son (he's a bit less than 150cm) an XS Giant, and it comes with 170mm cranks FFS. Currently sourcing some 152mm cranks for him. FWIW, I'm 187cm tall with long legs. You'll take my 175mm cranks from my cold dead hands (I even run 175mm on my MTB, I can live with the odd pedal strike).
I would love for major manufacturers to have more crank sizes available. I think it's madness that they sell cranks in 2.5mm increments but nothing shorter than 165mm. It's as if a shoemaker was offering shoes in only three sizes, and the sizes were 10, 10.5 and 9.5!
I don’t think shorter cranks are for everyone. I’m 190cm tall and run 175s. Tried 170s and while I can see the benefit for getting low and aero, I hated the feeling when climbing, particularly out of the saddle. I never had a problem getting aero on 175s so I went back. I can see myself using 170s for time trialing. But for general road riding not so much. I got long legs. Maybe that’s the reason? I dunno.
I’m 190 too, with a +90 instep, I moved to 165’s on my MTB’s a few years ago - not only feels better but less catching on the ground too. Gravel/road is still 170, but will be changed once I work out which electronic groupset to buy. 60 y/o, so not so flexible, but enough to do a 300k last Saturday.
Dropped from 172.5 to 170 this year and it's definitely reduced soreness in the knees and hips when I'm riding lots. Played with 165s as well, and the hips were a bit more comfortable yet, but I did get that sense of falling over the front of the bike a bit.
It's worth mentioning Croder as a crank brand with a great range of crank lengths available. Years (decades) ago it was common practice to put shorter cranks on a fixie to allow high cadence and longer cranks on singlespeed mtb for more leverage uphill. Similar thinking to some of the advice here.
Still on 175mm. 188cm tall, long legs, long torso and short arms. FAI in left hip limits time spent in aero position, if I raced or did long rides would maybe consider 170mm but happy with it
Fascinating. Great stuff thanks. I'm 180 with short legs 29” inside. My partner is a similar height with significant longer legs. Sitting in plane it looks like my upper leg is 2 inches shorter! I have tried unsuccessfully to replace FSA Omega cranks. However watching your video makes me wonder. As my lower leg may be a normal for my height. I will continue to investigate. I have 3 bikes with 172 ish cranks! Again thanks.
I'm 180cm tall and have been riding 165 cranks for ages. I think though a lot of that came from riding fixed gear on the street, then moving to racing fixed gear on a velodrome. In those instances, 165's felt much easier to spin and nowadays it's sort of just what I'm used to (definitely a more of a spinner).
My vintage 90s road bike (size 55cm, so who knows what that refers to. The data just doesn't exist on the internet for the Giant CFR3 in this regard) has 170 cranks. I'm 5'10 and wear 32" inseam pants which when barefoot usually reach just below the top of my foot. So my to-the-floor inseam is likely 32.5-33". Anyway, 170 may be slightly too long for me, as when I'm bent over in the drops trying to pedal in full aero against the wind (its the midwest; you're going to hit a decent headwind unless the air is unbelievably hot, muggy, and still), my knees were almost brushing my chest, and at about 20mi I started getting a light ache in my dominant knee. I'd want a bike fit first, but I bet if I went to 165mm cranks, I'd be a lot better off. My mtb has 175mm cranks, but that's not as crucial due to riding position and the greater amount of time you ride coasting while standing on the pedals when doing trail riding. So, crank length being wrong isn't nearly as detrimental (unless you're XC racing) as it is when riding on drop bars on gravel or road.
Bike Fit James. Can you do a video on buying a mountain bike? Sizing etc.? I know, I know.... go get a bike fit. Problem is we have shit fitters in my area. A rough idea would be somewhat helpful. I ride a size 51 BMC SLR01 Team Machine 2023. 120 Stem. Saddle height is 715mm. Thanks! 5' 8" in height. 170mm cranks
5’11” and switched from 170s to 145s a few months ago, dropped the front end 50mm and reach increased by 10mm, back pain is gone and average speed has increased by around 1mph. Never…Going…Back.
I’m on the hunt to replace my left 4iiiii 172.5 5800 crank with a 165 7000, not in any rush but I do wish my 52cm Scott came with a shorter crank like my mtb
I have very short inseam. Went from 170 to 165 then to 160. That change from 165 to 160 is life changing. There is great beenfit to having your knee not going too high at the top of the stroke. You breathe better, you can assume better and more aero posture, your leg muscles are more relaxed.
Hi James, I’m 6’2” 34” inseam. Been riding for the last 9 years never feeling like a power sweet spot at pedal stroke. Suspect 175mm crank is too long, only feel power mash after I clear the top of pedal stroke..
Been riding 140mm cranks on my roadbike and have loved it. I think 150mm would have been better based on my inseam but none the less, it feels good. I may swap out for 150 over the winter and see how that feels on the trainer.
@@musclelessfitness2045 Cruz cranks off Ali express. $50 Canadian snowball coins for the crank. It runs GXP chainrings but wasn't an issue for me. They make spiders to adapt for that. I've been happy with the quality for my riding. Only issue is they're a mountain bike spindle length. So you have to play with spacers to remove the side to side play.
@@Jensen_MacD Thx for the info. So with spacers you can fix the side to side play, but you can still make it work on a road bike. I have a press-fit Bottom Bracket, so I'm not sure if I can install it.
@@musclelessfitness2045Yes. The spindle is 98mm between crank arms where the average road is like 93mm. So you need 5mm of spacers, which can be bought online. You can buy a variety of spacers for $5. You may want to place with how you space it to keep the chainline. Bur they use a 24mm spindle diameter like Shimano. So easy to find a BB.
Hi James thanks again for sharing this knowledge - are there any tell tail angles - in relation to the knee, hip and ankle , with the pedal at TDC (or just slightly before for most acute angle) that would have indicated potentially requiring shorter cranks ? I've found some literature that would suggest anything less than 70' would suggest reviewing crank lengths - for shorter in this case. This assumes the saddle height has the extended leg in the 140-145' range as mentioned in most text books. Thanks 👍
Can I make a suggestion? For listener outside UK/US is very hard to understand measures in imperial system. Whenever you say 5 foot 3, for example, if I want to have a clue of what that means, we probably have to stop the video and convert, otherwise something doesn't make sense. Whenever possible, please state the measures in metric system...
Can I make a suggestion? For listener in the US is very hard to understand measures in SI system. Whenever you say 170cm, for example, if I want to have a clue of what that means, we probably have to stop the video and convert, otherwise something doesn't make sense. Whenever possible, please state the measures in imperial system...
@MichaelGuzzo he is already stating measures in Imperial. Or did you didn't saw the video? My suggestion is to add, when he remembers, measures in metric system. It would make his videos have a greater reach and pass along the information that he wants to share, what is his main goal. In the end, why does that bother you?
When I am using 180mm cranks my average cadence is about 94 rpm, when using 175mm cranks my average cadence is around 88rpm. This seems counter intuïtief but it is reality. Should I conclude that 180mm fits me better? It feels better, unfortunately they are not easy available.(don't mention with powermeter) ,
With my position, 170 mm gives me too big closing of the knee joint. If I raise my saddle, I have too big of a knee extension. Hips are fine either way. 165 mm works perfectly. I'm 177 cm, but it doesn't really matter.
Take a look at riders in the Eddy Merckx era (there are plenty of pictures): Average height riders rode 175 mm cranks. Did they have it wrong? NO THEY DIDN'T! Back then, the pedal axle was positioned nearer to the ball of the foot Nowadays, it is popular to position the pedal axle more towards the instep. It is natural to use a shorter crank to provide the same hip clearance and knee angle. Merckx et al. had it right with longer cranks. Modern riders with shorter cranks also have it right because nothing has changed thanks to repositioned pedals.
Rather than the position of the foot over the pedal, I think the biggest difference is that riders back in the day often had posterior pelvic rotation in order to relieve pressure from the perineal area as a result of traditional saddle designs, as well as much less handlebar to saddle drop - both things that significantly opened up the hip angle compared to today, and meaning that they could tolerate a longer crank.
One big reason for ball of foot over pedal spindle in the old days was the leather and later plastic soles were flexy/ unstable. The carbon sole made the foot stable allowing the cleat to move back.
I'll add a different point - massive chainrings and small cassettes of that era made significant the fact that with a longer crank you need less force on the pedal to exert the same torque on the wheel. Also Merckx himself is 182 cm and rode 172.5 mm cranks, that's not very long at all actually. I have first hand experience with those exact numbers btw.
5:57 but should I also set my saddle back the same amount too? I went from 165mm to 160mm on my Scott Foil RC. Raised the saddle 5mm but kept the position behind the bottom bracket the same. I feel more pressure on my hands now.
Even more important than crank length is stance... Why do all crank lengths ( from 165 mm to 180mm) and bike frames. (from small to XXL) have the same stance. Pedal extensions are too extreme and not all pedals have an option for longer axles. Shimano only 4mm....new generation Speedplay's no options ... Cycling media tells you 2.5mm in crank length will change your world and even throw "aero" in the mix... but rarely mention stance or Qfactor 6:25 🤭
I feel the quads more with 165mm vs 170mm cranks, raising the saddle go match the height makes it worse, I also feel more weight on the hands and higher saddle pressure with smaller cranks. Personally I consider switching back to 170mm and I have 1.69m height
I dont get it. First says shorter cranks, you can sit lower and are more aero. Than at 5:58 says, as you reduce crank length you need to raise the saddle wit the same amount. That means less aero. What is it?
If the crank is too short - spilling over the crank, falling into the front of the bike - can't you correct this by moving the saddle further back (and lower)?
The bike that was built for your client with Achondroplasia did you make a video of i?. I use to work with a guy that had this and always wanted a real road bike. Is there a way you can do a follow up video????
There is a company 5dev that created an inseam measuring device help find the right crank length. Is this a viable option aside from a full on bile fit?
Is it better to step over a higher hurdle? would you prefer to jump onto a higher step? It's 10 -15 mm, not a tremendous difference to your overall fit/geo your height varies between 10 - 20mm from morning to night and you don't adjust / allow for that in your leverage torque hip function saddle interaction wet garbage equation do ya now ?
I’m curious where the idea of getting lower comes from (as mentioned in the video and other comments). Shorter cranks = increased seat height = not getting lower? Or am I missing something… 175 to 170 to 165 recently and much prefer it. I’m 5’10 with pretty regular proportions
For the guy with dwarfism on the Sarto, why did you guys not bring in his brake levers? (reduce the reach). Especially considering his very small hands
Im 6'5 and riding 175mm cranks. I do feel some trouble getting over the top of the pedal stroke. If I go to 165mm and I raise my saddle by 10mm, I basically have the same leg extension but have reduced the height of my pedalstroke by 20mm? 10mm for the shorter crank, but 10mm extra for raising the saddle. that now sounds very exciting as I'm not the most efficient I think. I struggle with high cadance as well, so I think that removing the height of my pedal stroke while keeping the same leg extension could make me more efficient and comfortable in aero position. Any faults in this logic?
think it's the opposite- shorter cranks need a higher saddle. That pushes the saddle back, so you need to put it forward to keep the same distance to the bars/hoods...
@@Bazza1968 Good point, but I remember Neill Stanbury mentioning with the shorter crank, your feet also move back. He said that the saddle might have to also move back a little to compensate for this.
Is it worth being concerned about small Q factor changes between cranksets? I want to get a different length but the majority of cranksets I find are slightly wider, at about 150 mm Q factor, than the old 105 with 144 mm Q factor that I have now. I'm 182 cm tall and rather wide shaped, but I find I like keeping my feet close together even while walking for instance. Is 150 mm Q actually kinda wide or am I deluded to think that?
I have a question about reach and core strength. I'm one of those people who has longer legs and a shorter torso, proportionally. I'm 5"6" and the my Felt Z100 size 51 has a stack of 540 mm and a reach of 372 mm. I felt hand numbness, so I took the stem from 80 mm to 60 mm, and rotated the bars back a few degrees to shorten the reach. And I still feel hand numbness after about 30-40 minutes of a ride. A bike mechanic basically told me that it's not the fit that's the problem with me, but that I need to build up my core strength and hold my torso up better. Since I don't recall you addressing it on your new channel or with Francis, I'd be curious your thoughts, James, on how overall conditioning affects a bike fit and if there's something to my lack of conditioning. FWIW, I am also confident that the bars are too wide for me and I plan to address that in the build of my next bike. Thanks.
Thanks for your comment, the bar width is probably playing a role but I’d suggest you get a bike fit before buying your next bike so you don’t end up in the same situation again
I don't understand. Shorter crank lengths can be useful in reducing excessive saddle height and lowering overall height, but when you put shorter cranks on you have to raise the saddle by the same amount? How can these two statements work together?
Question . I get why there need to be a increase saddle height but I would also think that with less hip impingement wouldn’t it be also a option to drop the saddle height?
No. Try standing with your knees bent at a 90° angle for 5 minutes. Time yourself. Maintain 90°. Now try standing with straight legs. In both ways of standing you accomplish the same thing but one greatly fatigues your legs. If squatting with a barbell on your shoulders the lower you go (starting from standing) your ability to handle weight becomes significantly more difficult the lower you go. If you're in the gym trying to gain muscle mass when squatting going as deep as you safely go is smart. Greater range of motion unfortunately is more fatiguing and leads to greater soreness for a given amount of work accomplished. When trying to produce power to propel yourself forward on a bike extreme ranges your legs are going to fatigue quicker and have more soreness limiting your ability to do quality rides the following days.
What is the effect of crank length on natural cadence? My assumption would be cadence would be faster in the same gear with shorter cranks. If you ride at the same power and cadence with a 170 and 165 crank would you be in a different gear?
Yes, shorter crankarms do increase your average cadence. If your new cadence is high enough that it's too fast for that gear you were usually in, then you may need to upshift one gear higher than you used to.
Just changed to 170mm from 175mm two days ago, as you recommended James! Curious to see what this will do in combination with changing from 50/34 with 11-32 cassette to 46/30 with 11-34 on my gravel/bike packing bike 😊
@@betterontap I like the gear ratio a lot. The low end helps me to do climbs much better and the high end is still more than fast enough for me. As the crank length change also came with the aforementioned changes, it is difficult to judge if it has an impact and what it potentially might be!
You can give it a try during a bike fitting appointment on a fit bike. My inseam is 77.8 cm and I ride on 165 mm crankarms (not analysed by a bike fitter yet, but I think I have a tendency to bob up & down at 120 - 130 RPM and above).
@@Bikefitjamesit makes you sense use 165mm crank for an individual of 175cms height and 82,5cms inseam? I suffer saddle soreness, but its dissapear when I lower the saddle a lot by 7-10mm but my knees almost hit my stomach
Hi James, I'm getting saddle sores on my sit bones equally on both sides. I've tried everything to get rid of them but can't seem to work it out. Could this be incorrect saddle width? Cheers, Fin
From my experience, 172.5 to 170 may be noticeable, but certainly 172.5 to 165 will be quite noticeable (in a good way if needed). I've found that 5mm increments seems to reap the most obvious differences.
Do not promote those shorter cranks just because a short rider, who also is used to pedal at extremely high cadences throughout his entire cycling career, happened to have won the latest Tour de France with them. This does not apply to tall riders (1.8 m and above) and everyone not able to spin +90 rpm in every gear.
It seems to me the only real metric when choosing crankarm length would be measuring power and oxygen uptake (FPT and/or VO2 max). I believe a repeatable increase/decrease of 1% would show positive/negative gains BUT every bike fitter in the world just says "because I say so" and not one offers any metrics to back up their claims. Show me the data before you start preaching about bike fit.
I thought the same thing until I thought about your leg at the bottom of the pedal stroke. For example, if you went from 175mm to 160 mm cranks, your foot is now 15mm closer to the saddle at the bottom of the pedal stroke. To keep your leg extension the same, you'd need to raise your saddle 15mm so that the distance between the pedal and the saddle would be the same as it was when your cranks were longer. The advantage, as I understand it, to shorter cranks is not at the bottom, but at the top of the pedal stroke where your foot/pedal is now farther away from the saddle (doubly once you raise the saddle) and so you have less hip impingement at the top of the pedal stroke. That said I got 50% in grade 10 biology so I just make it sound like I know what I'm talking about.
Understandable.... James talked a lot about hip impingement and knee flexon referring to the top of the stroke. Yet if you go from a 170 to a 160mm crank you have lost 10mm on the bottom of the stroke and loss of leg extension. Increasing the saddle height alleviates that fit problem. Helps you get a little lower too. If that's your thing. Cheers.
Short wheelbase bike sort crank arms, Long wheelbase bike long crank arms. Or a shorter crank arms to avoid your toe hitting the front mudguard if fitted.
i'd imagine pros need to look for even most miniscule optimalisation. for regular person 5 mm difference won't make any real difference. this latest fad with shorter cranks feels way overblown to me.
I'm 6ft6 with a 36 inch inside leg measurement and changed to 165mm crank arms from 175, first ride out took over 3 minutes off my go to hill test, I haven't got any knee, hip or back pain, I do yoga to help keep my muscles from being tight, plus certain knee exercises to strengthen them. Basically for me changing to 165mm crank arms has been a change for the better.
I've only ever had 170mm cranks, not by choice but because they were on the bike. I've always managed to get comfortable on bikes of all sizes by adjusting the stem and seatpost height/reach. I know my preferred leg extension and reach and have never really struggled to achieve it. I'm not racing but can enjoy full days in the saddle on and off road. My choice of saddles has changed over the years with short-nose, wide cut out now seeming best. I do think that there's more science and technology in today's cycling than I'll ever need (or want).
I had a hip replacement about 15 years ago (I am now 59), just last year I started to hear about the think about crank length and moved from a 172.5 to a 165 crank. The change has been awesome. My general riding is much more comfortable and I have no residual hip discomfort from riding (which I had previously). What is infuriating is that I have had many bike fitting sessions through the years and the idea of crank length was never discussed, even though my hip issues were always known. At one point (post hip replacement), I was on a 175 crank and suffering hip pain and not once did the bike fitter ever discuss crank length.
Interesting. After a crash, I had a total hip replacement 12 years ago at age 54. I've never experienced any pain or reduced range of motion, still using 175mm cranks. At 66, I'm still competing on road races as long as 90 miles.
Excellent video, thank you James and team. One small remark is that the background music is a little too loud (I would personally remove it altogether but at least reducing the volume would help focus better). Thank you again for the great work
Idem!
I second that. James' presence is enough in the room and we don't need music!
Riding 160mm as a 1.75m person with a gut and my power numbers were highest on a 160, did try down to 150. Matt Appleman has sold me two sets and with OEMs now making 160 and shorter we have plenty of options. I have found the opposite of what James said, for me,I feel more in the middle of the bike when climbing stood up. I get too far over the front with a longer crank (170) when standing climbing. We are all individuals :)
160mm road and 155mm gravel here. And 5cm shorter than you.
180cm tall and riding 160mm. Never been so comfortable and stable on a bike!
Hi, whats your inseam height?
I have been riding with 170mm cranks since they came on my size 50 Domane. After watching numerous videos I decided to try 165mm cranks. Even though I had to get the power meter too (SRAM Rival) I decided to go ahead with the change especially given the fact I am 5' 3" with an inseam of 750mm and felt there was only an up side in my situation. I ordered them Monday and had them installed yesterday as well as having another fit to make sure things were in line with where they should be.
Just got back from my first ride with them. A huge success! This season I was in the mid 16's on most rides with an occasional low to mid 17 mixed in. I hit a PR today with an average speed of 18.8 mph on a 55 mile ride with 2500 feet of climbing. Pretty excited with the ride.
I definately noticed things during the ride that I liked. First of all, I was able to keep pace with the other riders better on long gradual climbs spinning faster, which allowed me to switch into a harder gear more efficiently. I was also able to close any seperation much faster this way. Normally I am towards the back in this situation on group rides but today I kept pace better. Climbing was easier as I didn't feel like I had to "get over the top" of my pedal stroke in comparison to previous rides. Even though I didn't have knee pain with the 170's it was more comfortable on my knees during. Felt things more in the quads which I prefer. I learned I would rather spin up a bit to propel myself forward instead of powering up with my legs. Cardio over muscle fatigue. I did have to make minor adjustments at the beginning of the ride based on the fit but once I did everything felt great. Because we raised the seat without raising the bars I can also flatten my back and get more aero in both the drops and the hoods. Very glad I experimented with shorter cranks. Already sold my 170mm crank set. For me it was a win. Who knows. I may try 160mm cranks next season but I felt dropping from 170 to 160 off the bat was a bit much.
The fit rule is simple: if you can't pedal smoothly through the top of your pedal stroke when riding in the drops, you can benefit from shorter cranks. And cranks are rarely too short but often too long. I have a 32" inseam and ride 150mm cranks.
I'm 5'8" para-cyclist, (1 leg) and shorter cranks have been awesome!
I'm down to 160mm crank on my road bike and 155mm on the MTB.
James is spot on about fatigue and shorter cranks. Much easier to spin more (in a lower gear) and for longer with the short cranks compared to the 172.5 that the road bike came with. The MTB is just a spin machine now, not fast but not much stopping it.
I also ride with one leg and haven’t really tried smaller cranks beyond 175 to 172.5. Have you tried oval chainrings? I’ve wondered if they’d help with my, and I assume your, power distribution
My personal experience re: not having a long inseam, yet not being short. A larger bike, with shorter cranks allows me to get the saddle height optimal, and keep the fit reasonable. Much smoother, better on my hips, and a not too small frame that would put me in an overly aggressive position. With the somewhat loss of torque due to the shorter cranks, I've changed my gearing to fit. Personally, I think crank length is perhaps the most important factor re: bike fit, as it greatly affects your position on the bike.
What's your inseam? Mines 32 inches yet I'm 6foot 2
At 185cm tall and being long limbed ive always used 175 mm cranks for all my cycling. Never knowingly had a problem
Good to see you posting yourself. Your advice and insight is really interesting 👍
I'm so psyched you have your own channel now! I've learned so much over the past few years. Your videos inspired me to book a fit with an IBFI fitter. Most comfortable bike I've ever ridden! I'd LOVE to see a video about the differences between gravel and road fitting. In particular, I'm interested in how local terrain impacts fit. Anecdotally it would seem that reach is impacted by the class of gravel you're on. I live in New England. 80 to 120 feet per mile average elevation is not uncommon. Also, unmaintained roads are common. Lots of Class 3+ stuff over here. Due to the elevation we get a lot of chunky conditions due to erosion. I think the reach on the bike I bought is too long. It felt great on a test ride, but that was 2000+ miles of gravel prior, when my only other experience was 40 years of being a roadie. It's a Trek Checkpoint (the frame my fitter selected turned out to be a 52 cm H1.5 Trek Emonda). I ended up lobbing off 1.5 cm from the front with a shorter stem and shorter reach bars, and probably 1 cm from the back by running my cleats as midsole as possible on Lake MX238s, thus bringing the saddle forward a bit. So it's workable now, but I still feel like another 1 to 1.5 cm needs to come off of that bike in order to handle long chunkier days.
That said... I just did some gravel riding in Eastern Ontario. FLAT AS A PANCAKE and mile after mile of perfectly maintained hero gravel. In those conditions, the Checkpoint is absolutely brilliant. Anyhow, I'd really be curious to hear your take on gravel geometries and what you need to consider, especially if you're a roadie. Despite how popular gravel has become, I find there to be a knowledge gap amongst the local fitters WRT gravel geometry.
I'm 164cm tall and a couple of years ago started to get a bit of knee pain after lots of cycling (ie daily rides) and nearly all my bikes were 170mm cranks (except mtb at 175mm) but I realised that on the newest bike I had (thankyou Wiggle and Vitus) with 165mm cranks I had no knee pain. Since then I have converted to 165mm or less with the shortest at 150mm with no obvious detriment and possibly the optimum at 160mm. Obviously everyone is different but I just wish it would have been a bit easier to try out shorter lengths a few years ago! Thankyou Shimano for now going down to 160mm and thankyou to Rotor for going even lower!
I see Bike fit james I click! happy to see the moevement in this channel! Hope it grows :)
Hi James,
I really love your content one day I will come to the uk and get a fit. At the moment I am looking for a more comfortable bike. I still have to decide between two sizes. I could either get a small frame which would result in a same stack figure as my current setup but also 16mm less reach. On the other hand I could take a medium which would result in 23mm more stack and 13mm less reach. The main downside of the medium frame is that it comes with a longer cockpit than my current setup. So the effective reach would be roughly the same. My main goal is the reduce pressure in my hands.
Keep up the great work! All the best,
David
I do think we need to clear both the knee and the hip when testing crank length. As important as it is to not go beyond safe hip flexion it is also equally important to not go beyond safe knee flexion to prevent things like chondromalacia/quadriceps tendinosis/patellar tendinosis. Its important to both clear the knee and hip markers.
I remember what the 170mm cranks did to my knees. So much happier on 160s.
I know it’s hard to find but Shimano makes a 167.5m in Dura Ace! I found both cranksets in Japan! Great video and analysis!
Loving the content! The downside of being tall is I always get super wide handlebars and 175 cranks. The handlebars are easy to change but the cranks not so much!!
Yess! And nowadays changing the handlebars is a much more complicated job than replacing the cranks.
5’3 and been riding with 170mm cranks for years. I’ve had several bike fits and each time I’ve compared of saddle issues (one side only) was always either told to ride more or that I didn’t have the right saddle. Finally riding with 165mm cranks and that small change has made a huge difference.
I'm only a little taller than you and ride 160mm on the road bike and 155mm on gravel.
@@phil_d still have 170 on my gravel bike. Was told I didn’t need 165 for my gravel bike. Issues from the bike fit have kept me off my gravel bike.
@@Cal906lil I'm surprised you don't have issues with toe overlap if you have 700c wheels.
I would definitely be looking at dropping cranks ength and raising the saddle slightly. And trying a different bike fitter!
Maybe I'll try shorter cranks at some point. I'm ~5'3" too, and on the normal 172.5mm cranks (pretty sure). I don't notice a major problem right now, but perhaps it is worth considering for my longevity as a cyclist.
I do have toe-overlap trouble on my road bike, but only while in the city going slow at stop lights - like needing to make a slow turn after a stop. If I have the speed to lean into a turn, it isn't an issue. On my commuter bike it rarely is trouble, as she's longer anyway.
I started riding 165s on my mtb years back to help with pedal strikes in rough terrain, gradually swapped every bike to 165s, now running 160s and 155s on a couple of bikes with equal success. Just feels so much more comfortable and less fatiguing on long distances.
Traditionally, 6 1/2" ( 165 mm ) were for the velodrome. 6 3/4" ( 170 mm ) were for the road & 7" ( 175 mm ) were for touring.
An experienced cyclist can mix 170 and 175.
6 1/4" ( 160 mm ) were small lady's cranks. 6" ( 150 mm ) were really small riders & juniors. 5" ( 130 mm ) were 'enfants'.
There is a formula which involves a percentage of the 'hip height'. The centre of your hip ball joint from the floor.
Another extra video and more bikefit magic! Thanks James!!!
There was a time when anyone under five foot eight was told to use 170. Anyone over six foot was put on 175. In between it was 172.5. Tall and short people were told they'd get used to it while the average height crowd never stopped discussing which length to go for. Before that TA in the past had all the lengths from 150-185. Comparing running stride of tall and short runners, tall runners have a longer stride length, but not proportionately longer. Short runners have a shorter stride length, but not proportionately shorter. A way to work out a good crank length is to calibrate at 172.5 for five foot ten and add or subtract half of the percentage leg length difference as the legs get longer or shorter. For legs ten percent longer use five percent longer cranks. For legs ten percent shorter use five percent shorter cranks, etc.
It's good to consider all these things, new technology gives better ways to improve riders comfort and efficiency. But what happens if you change your shoes, or pedals, or both? A few mm could be taken up by sole or pedal thickness and then you're back to square one. I don't know I'm just a nobody but I'm always interested.
Been riding 165mm for 5 years now, never looked back...
Never had an issue with crank lengths 170-175 just work. (I could see 170 as better for TT position) Freaking bar widths grr. Modern bikes are always too wide. I ride traditional french, fit flat top tube bikes 61cm to 25in size.
I switched from 172 to 165 and wow what a difference it made. So much easier to get over the top of the pedal stroke and get the power down. Noticed it most when climbing.
I bought a new bike online a few months ago and probably made the mistake of buying a size too large, because the small had a 165mm crank and I thought “wow that’s ridiculous”. Wish I would have watched this video first!
@@tkbuz frame size and crank length don't have to go together. I have a medium frame, but switched to shorter cranks. My upper body is long and my legs short. I had a bike fit and shorter cranks were the recommendation.
Been waiting for this vid from James. After he made this comment about crank length on Francis' channel a year or so ago I wanted to know if he'd had a change of mind with the new push to shorter cranks.
Also, on the topic of cranks, I bought my average height 10YO son (he's a bit less than 150cm) an XS Giant, and it comes with 170mm cranks FFS. Currently sourcing some 152mm cranks for him.
FWIW, I'm 187cm tall with long legs. You'll take my 175mm cranks from my cold dead hands (I even run 175mm on my MTB, I can live with the odd pedal strike).
I would love for major manufacturers to have more crank sizes available. I think it's madness that they sell cranks in 2.5mm increments but nothing shorter than 165mm. It's as if a shoemaker was offering shoes in only three sizes, and the sizes were 10, 10.5 and 9.5!
Great vid James, keep 'em coming!
I don’t think shorter cranks are for everyone. I’m 190cm tall and run 175s. Tried 170s and while I can see the benefit for getting low and aero, I hated the feeling when climbing, particularly out of the saddle. I never had a problem getting aero on 175s so I went back. I can see myself using 170s for time trialing. But for general road riding not so much. I got long legs. Maybe that’s the reason? I dunno.
Same here bro
I’m 190 too, with a +90 instep, I moved to 165’s on my MTB’s a few years ago - not only feels better but less catching on the ground too.
Gravel/road is still 170, but will be changed once I work out which electronic groupset to buy.
60 y/o, so not so flexible, but enough to do a 300k last Saturday.
At 190cm. 175 cranks are “short” cranks for you. Old school thoughts would have had you on 180+
@@Jonbsp well aware, I was old skool once with 180mm XTR cranks 🤣
Dropped from 172.5 to 170 this year and it's definitely reduced soreness in the knees and hips when I'm riding lots. Played with 165s as well, and the hips were a bit more comfortable yet, but I did get that sense of falling over the front of the bike a bit.
A recent bike fit put on 165’s.. Seems good
It's worth mentioning Croder as a crank brand with a great range of crank lengths available.
Years (decades) ago it was common practice to put shorter cranks on a fixie to allow high cadence and longer cranks on singlespeed mtb for more leverage uphill. Similar thinking to some of the advice here.
Long cranks on a fixie could kill you
Still on 175mm. 188cm tall, long legs, long torso and short arms. FAI in left hip limits time spent in aero position, if I raced or did long rides would maybe consider 170mm but happy with it
Well put, thank you.
I’m 5’2” and ride a 48-49 cm bike. The 165 mm crank is the jam.
Fascinating. Great stuff thanks. I'm 180 with short legs 29” inside. My partner is a similar height with significant longer legs. Sitting in plane it looks like my upper leg is 2 inches shorter! I have tried unsuccessfully to replace FSA Omega cranks. However watching your video makes me wonder. As my lower leg may be a normal for my height. I will continue to investigate. I have 3 bikes with 172 ish cranks! Again thanks.
I'm 180cm tall and have been riding 165 cranks for ages. I think though a lot of that came from riding fixed gear on the street, then moving to racing fixed gear on a velodrome. In those instances, 165's felt much easier to spin and nowadays it's sort of just what I'm used to (definitely a more of a spinner).
My vintage 90s road bike (size 55cm, so who knows what that refers to. The data just doesn't exist on the internet for the Giant CFR3 in this regard) has 170 cranks. I'm 5'10 and wear 32" inseam pants which when barefoot usually reach just below the top of my foot. So my to-the-floor inseam is likely 32.5-33".
Anyway, 170 may be slightly too long for me, as when I'm bent over in the drops trying to pedal in full aero against the wind (its the midwest; you're going to hit a decent headwind unless the air is unbelievably hot, muggy, and still), my knees were almost brushing my chest, and at about 20mi I started getting a light ache in my dominant knee.
I'd want a bike fit first, but I bet if I went to 165mm cranks, I'd be a lot better off.
My mtb has 175mm cranks, but that's not as crucial due to riding position and the greater amount of time you ride coasting while standing on the pedals when doing trail riding. So, crank length being wrong isn't nearly as detrimental (unless you're XC racing) as it is when riding on drop bars on gravel or road.
Bike Fit James. Can you do a video on buying a mountain bike? Sizing etc.? I know, I know.... go get a bike fit. Problem is we have shit fitters in my area. A rough idea would be somewhat helpful. I ride a size 51 BMC SLR01 Team Machine 2023. 120 Stem. Saddle height is 715mm. Thanks! 5' 8" in height. 170mm cranks
I am a 165mm convert and I am willing to give the 155mm a try if it is more easily available without ordering a custom crankset
5’11” and switched from 170s to 145s a few months ago, dropped the front end 50mm and reach increased by 10mm, back pain is gone and average speed has increased by around 1mph. Never…Going…Back.
Great video, thank you.
I’m on the hunt to replace my left 4iiiii 172.5 5800 crank with a 165 7000, not in any rush but I do wish my 52cm Scott came with a shorter crank like my mtb
Well, I’ve always loved my 175s. Moved to 172.5 and was canned on the hills straight away. Hoping it’s just an adaption period.
I have very short inseam. Went from 170 to 165 then to 160. That change from 165 to 160 is life changing. There is great beenfit to having your knee not going too high at the top of the stroke. You breathe better, you can assume better and more aero posture, your leg muscles are more relaxed.
Hi James, I’m 6’2” 34” inseam. Been riding for the last 9 years never feeling like a power sweet spot at pedal stroke. Suspect 175mm crank is too long, only feel power mash after I clear the top of pedal stroke..
for clydesdale and mashers i dont see how a 165 mm crank would work! I ride 177.5 and 180mm cranks!
Been riding 140mm cranks on my roadbike and have loved it. I think 150mm would have been better based on my inseam but none the less, it feels good. I may swap out for 150 over the winter and see how that feels on the trainer.
where did you buy the 140'S? Hoping it doesn't cost 500$ +
@@musclelessfitness2045 Cruz cranks off Ali express. $50 Canadian snowball coins for the crank. It runs GXP chainrings but wasn't an issue for me. They make spiders to adapt for that.
I've been happy with the quality for my riding. Only issue is they're a mountain bike spindle length. So you have to play with spacers to remove the side to side play.
@@Jensen_MacD Thx for the info. So with spacers you can fix the side to side play, but you can still make it work on a road bike.
I have a press-fit Bottom Bracket, so I'm not sure if I can install it.
@@musclelessfitness2045Yes. The spindle is 98mm between crank arms where the average road is like 93mm. So you need 5mm of spacers, which can be bought online. You can buy a variety of spacers for $5.
You may want to place with how you space it to keep the chainline. Bur they use a 24mm spindle diameter like Shimano. So easy to find a BB.
Hi James thanks again for sharing this knowledge - are there any tell tail angles - in relation to the knee, hip and ankle , with the pedal at TDC (or just slightly before for most acute angle) that would have indicated potentially requiring shorter cranks ?
I've found some literature that would suggest anything less than 70' would suggest reviewing crank lengths - for shorter in this case.
This assumes the saddle height has the extended leg in the 140-145' range as mentioned in most text books.
Thanks 👍
188cm here - went from 175 to 172.5… subtle but pleasant development
Can I make a suggestion? For listener outside UK/US is very hard to understand measures in imperial system. Whenever you say 5 foot 3, for example, if I want to have a clue of what that means, we probably have to stop the video and convert, otherwise something doesn't make sense. Whenever possible, please state the measures in metric system...
I use mm, cm, m, km.... I skip... clips that use feet ,pounds,
Can I make a suggestion? For listener in the US is very hard to understand measures in SI system. Whenever you say 170cm, for example, if I want to have a clue of what that means, we probably have to stop the video and convert, otherwise something doesn't make sense. Whenever possible, please state the measures in imperial system...
@MichaelGuzzo he is already stating measures in Imperial. Or did you didn't saw the video? My suggestion is to add, when he remembers, measures in metric system. It would make his videos have a greater reach and pass along the information that he wants to share, what is his main goal. In the end, why does that bother you?
When I am using 180mm cranks my average cadence is about 94 rpm, when using 175mm cranks my average cadence is around 88rpm. This seems counter intuïtief but it is reality. Should I conclude that 180mm fits me better? It feels better, unfortunately they are not easy available.(don't mention with powermeter) ,
Power meter makes them unnecessarily expensive. Imo😊
I hope mine is not wrong since I had a bike fit with you 😅
With my position, 170 mm gives me too big closing of the knee joint. If I raise my saddle, I have too big of a knee extension. Hips are fine either way. 165 mm works perfectly. I'm 177 cm, but it doesn't really matter.
Same. And I’m 178cm
Take a look at riders in the Eddy Merckx era (there are plenty of pictures): Average height riders rode 175 mm cranks. Did they have it wrong? NO THEY DIDN'T! Back then, the pedal axle was positioned nearer to the ball of the foot Nowadays, it is popular to position the pedal axle more towards the instep. It is natural to use a shorter crank to provide the same hip clearance and knee angle. Merckx et al. had it right with longer cranks. Modern riders with shorter cranks also have it right because nothing has changed thanks to repositioned pedals.
Rather than the position of the foot over the pedal, I think the biggest difference is that riders back in the day often had posterior pelvic rotation in order to relieve pressure from the perineal area as a result of traditional saddle designs, as well as much less handlebar to saddle drop - both things that significantly opened up the hip angle compared to today, and meaning that they could tolerate a longer crank.
One big reason for ball of foot over pedal spindle in the old days was the leather and later plastic soles were flexy/ unstable. The carbon sole made the foot stable allowing the cleat to move back.
I'll add a different point - massive chainrings and small cassettes of that era made significant the fact that with a longer crank you need less force on the pedal to exert the same torque on the wheel. Also Merckx himself is 182 cm and rode 172.5 mm cranks, that's not very long at all actually. I have first hand experience with those exact numbers btw.
5:57 but should I also set my saddle back the same amount too? I went from 165mm to 160mm on my Scott Foil RC. Raised the saddle 5mm but kept the position behind the bottom bracket the same. I feel more pressure on my hands now.
Saddle fore & aft can be left as is.
Awesome! 💯😎👍
Even more important than crank length is stance...
Why do all crank lengths ( from 165 mm to 180mm) and bike frames. (from small to XXL) have the same stance.
Pedal extensions are too extreme and not all pedals have an option for longer axles. Shimano only 4mm....new generation Speedplay's no options
...
Cycling media tells you 2.5mm in crank length will change your world and even throw "aero" in the mix... but rarely mention stance or Qfactor 6:25 🤭
I bought axle extension 16mm per side. Try these
I feel the quads more with 165mm vs 170mm cranks, raising the saddle go match the height makes it worse, I also feel more weight on the hands and higher saddle pressure with smaller cranks. Personally I consider switching back to 170mm and I have 1.69m height
Whats your height and inseam? Regards
@@franciscopizarroi Height is 1.69m and inseam about 76cm. Cheers
I dont get it. First says shorter cranks, you can sit lower and are more aero. Than at 5:58 says, as you reduce crank length you need to raise the saddle wit the same amount. That means less aero. What is it?
Ass is higher, head is lower. 😅
if you are 5'11" you can think about 170-172.5mm
5'1-5'2 can/should? still look at 165mm crankarms !!!
Yes, or even shorter
If the crank is too short - spilling over the crank, falling into the front of the bike - can't you correct this by moving the saddle further back (and lower)?
That's what I'm also wondering. I do remember Neill Stanbury mentioning that in a video.
The bike that was built for your client with Achondroplasia did you make a video of i?. I use to work with a guy that had this and always wanted a real road bike. Is there a way you can do a follow up video????
James I have pudendal nerve pain, have you seen this happen before from cycling?
There is a company 5dev that created an inseam measuring device help find the right crank length. Is this a viable option aside from a full on bile fit?
Is it better to step over a higher hurdle? would you prefer to jump onto a higher step? It's 10 -15 mm, not a tremendous difference to your overall fit/geo your height varies between 10 - 20mm from morning to night and you don't adjust / allow for that in your leverage torque hip function saddle interaction wet garbage equation do ya now ?
I’m curious where the idea of getting lower comes from (as mentioned in the video and other comments). Shorter cranks = increased seat height = not getting lower? Or am I missing something…
175 to 170 to 165 recently and much prefer it. I’m 5’10 with pretty regular proportions
2 videos in a week?
its not the size of the cranks that matters
For the guy with dwarfism on the Sarto, why did you guys not bring in his brake levers? (reduce the reach). Especially considering his very small hands
Didn’t need to because his bike fits him
@@Bikefitjames yes of course, but I'm only talking about the brake levers. (reach adjustment)
Im 6'5 and riding 175mm cranks. I do feel some trouble getting over the top of the pedal stroke. If I go to 165mm and I raise my saddle by 10mm, I basically have the same leg extension but have reduced the height of my pedalstroke by 20mm? 10mm for the shorter crank, but 10mm extra for raising the saddle. that now sounds very exciting as I'm not the most efficient I think. I struggle with high cadance as well, so I think that removing the height of my pedal stroke while keeping the same leg extension could make me more efficient and comfortable in aero position. Any faults in this logic?
Shouldn't you also move the saddle back after reducing crank length?
think it's the opposite- shorter cranks need a higher saddle. That pushes the saddle back, so you need to put it forward to keep the same distance to the bars/hoods...
@@Bazza1968 Good point, but I remember Neill Stanbury mentioning with the shorter crank, your feet also move back. He said that the saddle might have to also move back a little to compensate for this.
Is it worth being concerned about small Q factor changes between cranksets? I want to get a different length but the majority of cranksets I find are slightly wider, at about 150 mm Q factor, than the old 105 with 144 mm Q factor that I have now. I'm 182 cm tall and rather wide shaped, but I find I like keeping my feet close together even while walking for instance. Is 150 mm Q actually kinda wide or am I deluded to think that?
My bike came with bloody 175mm cranks 😂 hate it
I have a question about reach and core strength. I'm one of those people who has longer legs and a shorter torso, proportionally. I'm 5"6" and the my Felt Z100 size 51 has a stack of 540 mm and a reach of 372 mm. I felt hand numbness, so I took the stem from 80 mm to 60 mm, and rotated the bars back a few degrees to shorten the reach. And I still feel hand numbness after about 30-40 minutes of a ride. A bike mechanic basically told me that it's not the fit that's the problem with me, but that I need to build up my core strength and hold my torso up better. Since I don't recall you addressing it on your new channel or with Francis, I'd be curious your thoughts, James, on how overall conditioning affects a bike fit and if there's something to my lack of conditioning. FWIW, I am also confident that the bars are too wide for me and I plan to address that in the build of my next bike. Thanks.
Thanks for your comment, the bar width is probably playing a role but I’d suggest you get a bike fit before buying your next bike so you don’t end up in the same situation again
I don't understand. Shorter crank lengths can be useful in reducing excessive saddle height and lowering overall height, but when you put shorter cranks on you have to raise the saddle by the same amount? How can these two statements work together?
By rising the saddle you put your torso more parallel to the road. It's not a total height reduction but rather just a more aero position
@Bikefitjames - can you explain this a bit more?
@@mr_rider7591 I recently shot a 'Responding to your comments' video which is coming very soon, this comment is in that video :)
Is this your official channel? I wanna subscribe, please let me know lol I see you all the time on Cade
This is a new channel directly from James.
Question . I get why there need to be a increase saddle height but I would also think that with less hip impingement wouldn’t it be also a option to drop the saddle height?
No. Try standing with your knees bent at a 90° angle for 5 minutes. Time yourself. Maintain 90°. Now try standing with straight legs. In both ways of standing you accomplish the same thing but one greatly fatigues your legs. If squatting with a barbell on your shoulders the lower you go (starting from standing) your ability to handle weight becomes significantly more difficult the lower you go. If you're in the gym trying to gain muscle mass when squatting going as deep as you safely go is smart. Greater range of motion unfortunately is more fatiguing and leads to greater soreness for a given amount of work accomplished. When trying to produce power to propel yourself forward on a bike extreme ranges your legs are going to fatigue quicker and have more soreness limiting your ability to do quality rides the following days.
Don't forget that you can see three bike fitters and they would all give you different results.
Three good ones wouldn’t
@@Bikefitjames absolute garbage
@@markstone722I am sure you are correct - thanks for commenting!
I suffer from pain in the nose of the saddle and I’m with 160 mm should I try 165 mm?
Crotch discomfort is caused by saddle angle and length. You can tilt your saddle a little nose down or consider using a short-nose saddle.
What is the effect of crank length on natural cadence?
My assumption would be cadence would be faster in the same gear with shorter cranks.
If you ride at the same power and cadence with a 170 and 165 crank would you be in a different gear?
Yes, shorter crankarms do increase your average cadence. If your new cadence is high enough that it's too fast for that gear you were usually in, then you may need to upshift one gear higher than you used to.
Just changed to 170mm from 175mm two days ago, as you recommended James! Curious to see what this will do in combination with changing from 50/34 with 11-32 cassette to 46/30 with 11-34 on my gravel/bike packing bike 😊
How's it feeling so far? Do you notice much difference with just a 5mm reduction?
Very good combo. I think you will love it.
How tall are you?
@@michaels.8388 1.83
@@betterontap I like the gear ratio a lot. The low end helps me to do climbs much better and the high end is still more than fast enough for me.
As the crank length change also came with the aforementioned changes, it is difficult to judge if it has an impact and what it potentially might be!
Doesn't a shorter crank increase saddle height?
Yes. At the same time, your thighs won't be as close to your torso on pedal upstrokes.
Im 5ft5inch riding 170mm crank,is it better for me riding 165mm crank to increase cadence & power?
You can give it a try during a bike fitting appointment on a fit bike. My inseam is 77.8 cm and I ride on 165 mm crankarms (not analysed by a bike fitter yet, but I think I have a tendency to bob up & down at 120 - 130 RPM and above).
It appears that most of us are riding bikes that are too big, have saddles too high and cranks that are too long!
I’d go with that yeah
@@Bikefitjamesit makes you sense use 165mm crank for an individual of 175cms height and 82,5cms inseam? I suffer saddle soreness, but its dissapear when I lower the saddle a lot by 7-10mm but my knees almost hit my stomach
Hi James,
I'm getting saddle sores on my sit bones equally on both sides. I've tried everything to get rid of them but can't seem to work it out. Could this be incorrect saddle width?
Cheers,
Fin
I'm not james, but drop you seat height a a bit
So, is it worth going from 172.5 to 170? or just go lower than that? 165 ?
I can tell the difference between 172.5 and 170, best to test it first though innit!
From my experience, 172.5 to 170 may be noticeable, but certainly 172.5 to 165 will be quite noticeable (in a good way if needed). I've found that 5mm increments seems to reap the most obvious differences.
Desperately trying to find a 160mm 24mm spindle crank
Shimano
Or Rotor ALDHU24 if your budget allows it. This model is also easier to find than a 160 mm Shimano crankset.
Or Rotor ALDHU24 if your budget allows it. This model is also easier to find than a 160 mm Shimano crankset.
Do not promote those shorter cranks just because a short rider, who also is used to pedal at extremely high cadences throughout his entire cycling career, happened to have won the latest Tour de France with them. This does not apply to tall riders (1.8 m and above) and everyone not able to spin +90 rpm in every gear.
Explain Fillipo Ganna at 6ft3 on 165mm cranks Olympic TT ???? I bet thats vgot you stumped
Not really, it’s covered in this video, I talked about triathlon but TT is the theory
if i have to change cranks on my new bike its gonna cost like $300 more lol
170 чтобы в магазин за пивом ездить. 150 оптимальная длина для роста 186
155 is the new 175
It seems to me the only real metric when choosing crankarm length would be measuring power and oxygen uptake (FPT and/or VO2 max). I believe a repeatable increase/decrease of 1% would show positive/negative gains BUT every bike fitter in the world just says "because I say so" and not one offers any metrics to back up their claims. Show me the data before you start preaching about bike fit.
Reduce the crank length, increase saddle height sounds counter intuitive to me.
But then I’m not a bike fitter. 🤷♂️
I thought the same thing until I thought about your leg at the bottom of the pedal stroke. For example, if you went from 175mm to 160 mm cranks, your foot is now 15mm closer to the saddle at the bottom of the pedal stroke. To keep your leg extension the same, you'd need to raise your saddle 15mm so that the distance between the pedal and the saddle would be the same as it was when your cranks were longer.
The advantage, as I understand it, to shorter cranks is not at the bottom, but at the top of the pedal stroke where your foot/pedal is now farther away from the saddle (doubly once you raise the saddle) and so you have less hip impingement at the top of the pedal stroke. That said I got 50% in grade 10 biology so I just make it sound like I know what I'm talking about.
@@davidv6803 oh yes, now that makes sense 👍
Understandable.... James talked a lot about hip impingement and knee flexon referring to the top of the stroke. Yet if you go from a 170 to a 160mm crank you have lost 10mm on the bottom of the stroke and loss of leg extension. Increasing the saddle height alleviates that fit problem. Helps you get a little lower too. If that's your thing. Cheers.
@@davidv6803 Yes, your foot at the top of the crank will be 30mm lower.
I was thinking the same but this makes perfect sense now thanks!
Short wheelbase bike sort crank arms, Long wheelbase bike long crank arms. Or a shorter crank arms to avoid your toe hitting the front mudguard if fitted.
i'd imagine pros need to look for even most miniscule optimalisation. for regular person 5 mm difference won't make any real difference. this latest fad with shorter cranks feels way overblown to me.
That’s probably because you don’t understand what it impacts, perhaps I should have been clearer in this video….
I'm 6ft6 with a 36 inch inside leg measurement and changed to 165mm crank arms from 175, first ride out took over 3 minutes off my go to hill test, I haven't got any knee, hip or back pain, I do yoga to help keep my muscles from being tight, plus certain knee exercises to strengthen them. Basically for me changing to 165mm crank arms has been a change for the better.
This week on things that never happened
I asked too soon. Sorry.
I've only ever had 170mm cranks, not by choice but because they were on the bike. I've always managed to get comfortable on bikes of all sizes by adjusting the stem and seatpost height/reach. I know my preferred leg extension and reach and have never really struggled to achieve it. I'm not racing but can enjoy full days in the saddle on and off road. My choice of saddles has changed over the years with short-nose, wide cut out now seeming best. I do think that there's more science and technology in today's cycling than I'll ever need (or want).