Crank lengths

nevets84

As the title suggests, how do i know which length cranks to buy. I'm looking at Shimano XT770's on a Santa Cruz Heckler. Thanks

ride_whenever

175mm cranks are good for most people, the differences are minimal and you only really need shorter if the bike has a really low bb (esp at full compresssion), or you have really short legs, or you have knee issues so prefer a bit less flex and the top.

Basically if you don't have any issues with the old ones, buy 175mm!

robertpb

As you did not say what your inside leg measurement is there isn't a way of giving you the correct answer.

My cranks are 170 mm which is about as far as I can go, if I used 175mm my knees would suffer in the long term. It's all to do do with the longer the cranks the shorter the legs the more flexing on the knees.

---

Always ask a teenager as they know it all

nicklouse

On MTB's 99% of the population use the standard 175mm cranks.

there is a formula for working it all out in the tech links sticky, but it is more road based and not that relevant to XC or any other general MTB usage unless you are a pro XC er.

for referance i use cranks from 175,170 and 165mm

ddraver

Hmm I'd be carteful; here - I'm 170cm and feel far far more comfortable with 170mm cranks on both MTB and road bikes!!

Konahed

Get the same length you're used to. Unless you have knee problems or whatever. I would say though if you're about 5ft8 or less 170mm may be the way to go.

dunker

5'9" here and i find 170mm much better on the ol knees.