Why Shorter Cranks? - PART 2 - GreshFit Bike Fitting

[@jblocker6613]

Years ago I bought a Trek 62cm road bike that amazingly had 170mm cranks on it. I’m guessing it was a factory mistake but it worked really well for me. Years later after selling that bike for a xl frame Giant Defy I never felt like my peddling was quite as smooth and fast as my Trek was. I decided I’m going to switch out the 175’s for 170’s. I think the reason why shorter cranks work for me is because my lower part of my legs are long compared to the upper part of my legs. I have a 35.5” inseam, btw. I think it helps round out my peddle stroke better. Thanks for sharing this information, nice video!

[@greshfit]

Very cool! Thanks for sharing - I’m glad those 170s snuck their way in!

[@al_peko]

that's right. crank length depends no only your height and inseam length, but also on the ratio of the length of the thigh and the length of the shin

[@duanefisher2367]

I'm 5' 8" with a 29" inseam - I bought a Specialized Creo SL Comp Carbon EVO as an early retirement present for myself so I could get back into cycling and expand my range to include gravel trails that I simply can't cover with my Giant Defy road bike. However, as my training rides got up to 20 - 25 miles I started having hip and knee pain and eventually went to Tim for a fitting. He adjusted my seat height, fore and aft position, changed my stem and recommended I go with 155mm cranks. (the bike comes with 175mm) I found a set of 160 mm that were compatible with my bike and the change has been amazing. Not only has my pain gone away, but my training rides are now up to 45-50 miles and cycling has become my go-to therapy. Thanks so much Tim you're amazing!

[@greshfit]

🤲

[@phil_d]

I'm 5'4" (163cm) and ride 155mm (Rotor, 24mm and 30mm universal options) and 160mm (Shimano R7100 12sp on an 11sp setup) cranks on my bike. I have limited range of motion with my left knee (poor form on 140kg squats) and shorter cranks have been a lifesaver for me. I like the benefit of being able to spin, especially on sprints (130rpm). Just a point to note, you may need to increase your gearing due to shortened lever arm. With Rotor, you can buy their 1-piece double chainring from 46/30 and up. For Shimano, consider a bigger cassette.

[@theisrandersen]

I'm 193cm and changed to from 175 to 185mm. Best upgrade I've ever done.

[@greshfit]

Congratulations

[@al_peko]

what is your cranks brand/model of 185mm? for road bikes I saw only 180,mm maximum

[@firmbutton6485]

5’7 here with 172.5 and just bought 165 to help my knees.

[@Chungleas]

I'm 5'10" and I've been on 170mm for about 16 years, recently (last 6 months or so) I have started to notice the occasional bit of knee and/or hip pain (especially at the beginning of a ride, more noticeable when the weather is cold or I'm not warmed up). I'm currently putting another bike together. I have the option of getting a 165 or even a 160mm crank and I'm erring towards the 160mm, in my head this potentially works as prevention for future knee/hip issues as I get older, but is that just nonsense? People only seem to go to shorter cranks after they've been doing damage with long cranks for a while, I'm keen to minimise future joint injuries if I can...

[@greshfit]

Hard to say without seeing you. But if you want to go on the safe it makes sense to go 160 Or - go 165 then 160 in a few years. Good luck !!👍

[@peadhill]

I just swapped 172.5 for 165. Partially just to see what it was like, also to get a little more clearance between my bike shoe and the front wheel. For some reason bike shoes only feel comfortable for me with the cleat much further back than typical recommendations. Anyhow, went out for 2 1/2 hours today. Seemed fine.

[@greshfit]

Sounds like you found a happy medium!

[@Pompdiepom]

After years of fiddling around with wedges due to knee pain I recently discovered that with 165 mm cranks ( & solestar insoles / neutral cleats placement maxed out towards the heel ) everything was ok again. This is totally overlooked, and I agree that 172.5 and 170 is the same. Pretty silly actually how people from 160cm to 200cm body length are now being sold a bike with 170/175 cranks. Handlebar width is another overlooked issue , 42cm is too wide for a lot of people.

[@greshfit]

💯

[@bayork]

@GreshFit, what is the make and model of the bike in the video.?

[@greshfit]

That is my own custom Seven gravel bike kzbin.info/www/bejne/hWrWiY2Cf8Z1kLssi=lsXD2DBoYQXxOVrx

[@Etk333]

5'11 and 170 feels amazing for me but since I prefer the clearance cause I run a track bike I stay with 165

[@romanpramuka2703]

Hi, I'm not a short rider at 5'11" (180cm) with 85 cm inseam, but I'm 50yo 75 kilo, not the best fit and flexibility. I'm currently using 165 mm Rotor cranks at all of my bikes and very happy with it. I want to improve my aero position on my aero bike and decrease it's weight in one shot, by using aldhu carbon cranks (currently vegast) Strangely, Rotor isn't offering 160mm (only 155 and 165) so I'm thinking about 155mm. Is here any drawback going to 155? Btw, I don't have any injuries to my knees or hips, I just feel it will be easier to keep TT like position with even more shorter cranks. Thanks.

[@greshfit]

In this case you won’t know until you try it. 155 should be fine. You might consider a cheap 160 crank from shimano to test out that length first. Good luck !

[@basvanleeuwen4502]

I am 1,97 but after continuing kneeboains I just switched from 175 to 170

[@andreashertig1869]

I am 192cm and ride 175mm cranks. I got knee and hip/lower back issues but only on one side. should I try a shorter crank anyway?

[@greshfit]

It wouldn’t hurt. If you have issues on one side then I’d highly recommend getting checked out by a direct-observation bike fitter

[@sccxvelo]

Thinking of going to shorter cranks on my CX/ gravel/ everyday bike. Tall person on size 58/ 60 or XL frames currently have 175mm so on the fence about it as bike part money needs to go else where for new fork, as stem with angled up 6-8 degrees stem on the very top of fork and cannot lower it or it will be a bad fit. Then longer cage on the RD for bigger cogs in back on 1x set with no FD cable routing. Tough call what to do first.

[@nadiemequire]

Would a shorter crank necessitate a height adjustment for the saddle?

[@greshfit]

Yep.... I usually start with raising the saddle 50% of the difference. So if going from 170 to 160, raise the saddle 5mm. Good luck!

[@nadiemequire]

@@greshfit OK, thanks. Appreciate your help.

[@senjo24553]

Hello im 5’5 and currently using 170mm can you recommend 165? and chainring is sram 48/35 with 11/36 12speed.

[@greshfit]

165 no question 160 better yet

[@IS-xk3iq]

Can the crank arm be separated from the crank or is it all one unit?

[@greshfit]

Depending on the brand - the crank arms and chain ring can be separated if that’s what you mean

[@johnnyboy4711]

Hi I am 179cm height with 91kgs, went from 170mm to 165mm on TT bike. Trying to tweak the fit (saddle height from bb and fore/aft from bars etc)from 170mm bikefit. Should the saddle rise by the same difference? 5mm

[@greshfit]

That’s right - with 165s raise your saddle 5mm.

[@taburetca]

178cm 172.5mm

[@harrytiongsonjabagat3491]

Im 5'5 feet and happy with 155mm cranks

[@madzonic16]

I'm 5'7" (170 cm) and will go from 165 to a 145mm cranks

[@BenSietze]

1.93m and recently went from 175 to 170mm just to give it a try. Haven’t made my mind up yet which I like better..

[@Natatae_ako]

I'm 5'6" and I have 165mm

[@senjo24553]

How was the experience ?im 5’5 and also planiing to try 165mm from 170mm.

[@CTINF]

@@senjo24553, I’m 5’7” and recently had a bike fit advised to go from 170 to 160.

[@eagerbob]

5 foot 6? I'll look that up.

[@greshfit]

Lol

[@myPPPLab]

spinning smaller circles----- may require bigger gears

[@aktux]

I think it's the opposite. spinning shorter cranks require slightly smaller gears becuase the gain ratio increases.