I’m thinking of getting some 165mm cranks for a new build, due to a low bb.

I would also get some thinner flat pedals (5mm thinner than the current) to offset the difference.

For people who have run different lengths, what difference have you found?

Pros and cons?

I changed both of my MTBs to 165mm. I am 6’1 but with short legs/long torso. I’ve had bad knees in the past and going from 175 to 165 has made a big difference. Shorter cranks are supposed to benefit the short of leg.

In terms of power, the only time I have noticed is on a very steep climb, with tired legs, pedalling in bottom gear. Any other time you just change gear accordingly.

Seat post will be 10mm higher.

I have long legs and went for shorter cranks but got sore knees so back to 175mm ones and they cleared up.

the difference between 175 and 165 is tiny (about 6%), don’t be surprised if you can’t tell.

Dear crank manufacturers: can you please, please, please, start making cranks that are actually different lengths? 165-to-175 is about as much use as the difference between an 18″ frame, and a 19″ frame.

I can tell the difference at 5’11 between the 175s on MTB and the 170s on the road bike. It’s subtle but after a while you really notice it. At least I do. It’s part of the general differences between the roadie and mtb. 170s are better for steady spinning imo.

FWIW a riding friend of mine who is very meticulous about set up claimed he couldn’t tell the difference when he got longer crank arms (from 170 to 175 I think).

i’m not surprised; that’s only a 3% change.

it’s like going from a 70mm stem to a 72.

6 ft 34 inch legs I just went from 170 to 175 I prefer 175.

6’1 with stupid stumpy 32″ legs, hence why 165’s work very well for me. Shame the choice of 165mm MTB crank arms is so limited.

Changes to crank length can be felt. 5mm can be noticed if you are sensitive. 10mm most definitely feels different, but I think after a while you get used to anything. Comparing it to a stem length change is a bit daft (stems aren’t levers spinning at 100 rpm)…..

We once experimented with 162.5mm cranks and swapping directly between a 175mm bike it felt very odd – like your foot dropped straight through the power stroke.

On another occasion my mrs has come back from a ride and enquired if bike x had different length cranks to bike y purely based on how it felt (there was 5mm difference when I checked).

If you’ve ridden bikes a lot and have your spin committed to muscle memory it’s fairly noticeable. 175s felt like all my pedalstrokes were mistimed and I was working against myself. back to 170s and it’s ok.

took me a good while to get used to 172.5 on my newest roadbike after years of 170s both on and off-road. still don’t like the 172.5s after 2000+ miles but just can’t justify the outlay to change right now

no idea if you will notice or not

I assume all you princesses get your shoes resoled monthly?

why would you need a solid sole with a cleat bolted to it re-soled… like ever… oh great, and wise queen?

i went from 175mm to 170mm and noticed a difference. im 6ft 2″ with long legs.
(wanted to attempt minimising pedal strikes that seemed to happen more on my lower bb bike.)
I’ve got use to it now but its a slight weird subtle adaption for your legs.
i’d reckon 10mm difference is a pretty big adjustment.

Unless your knees are suffering, surely getting a bike with a higher BB would be a better idea?

if good cornering characteristics don’t matter to you yes… hell, why not go the whole hog and buy one of those Fatbikes. I hear they’re specially designed to be used on big wide beaches with an ice cream shop at the end. Once you’ve finished your double 99 The ice cream vendor will happily help you turn it around so you can pedal it slowly back to your car.

My biggest issue with 165mm cranks was I found it quite hard to touch the floor with the seat at the perfect peddling height. Otherwise it was unnoticeable.

Lol..mtbel sometimes you are an arse but that made me chuckle 🙂

Noticed 165 -> 180 on the bmx

Didn’t notice 170 -> 175 on the road & mtb.

Oh joy son of GW is in the house…..

close…… 😆

I run short cranks to relieve knee pain (osteo-arthritis). I’ve tried 155, 160, 165, 170 and 175, and I’m 6′ tall, normal lush leg length…

In my experience, the following things are true:

1) While a short crank theoretically gives less leverage, in practice the leg being (on average) straighter during the power stroke seems to compensate for this. I find I can push a higher gear with short cranks than with long ones (when seated).
2) spinning is easier.
3) Out the saddle honking can be less efficient (you lose the straight-leg advantage mentioned above).
4) The saddle will be higher for a given leg length. So you may lose some fore-aft stability when climbing, and there’ll be marginally more times when a dropper post earns it keep. Both extremely marginal effects, though.

For me, short cranks work really well, and I think I’ll be sticking with 160/165 for the foreseeable future. Your physiology will be different, so it may or may not work for you. Give it a try… 😀

https://www.powercranks.com/cld.html

http://www.cervelo.com/en/engineering/ask-the-engineers/crank-length.html

CRANK LENGTH – Which one?

http://wbeauchamp08.serveronline.net/wisil/MartinDocs/Determinants%20of%20Maximal%20Cycling%20Power.pdf

Personally think it makes a huge difference, but everyone is different.