My GF is about 5'6" but doesn't have the womans MTB marketing proportions of long legs and short body, quite the opposite in fact. She currently has 175mm cranks, and prefers to spin away in a fairly low gear up climbs rather than stomping higher gears.

Would she see any benefit from shorter cranks?

I reckon she would if she's going to do lots of cycling. if it's just once in a while, then not so much.

I wondered the same thing though. My wire if 5'9". The wsd for her normally comes with 170mm cranks but she's got longer legs than me. Some migth say her legs are not as strong but surely that just means selecting a lower gear? Anyway, she got the mens version of the bike with 175mm cranks and we just swapped out the stem and saddle.

opinions differ between unbelievably massive difference to undetectable

Nice to hear there's a conclusive answer Simon! 😀

I rode for several months with 175 left and 170 right.If I concentrated really hard while on the road the left side felt slightly shorter…

I am 5ft 3" ish and ride the standard 170mm raceface cranks on the mtb but on my road bike I have 165mm TA vega lite cranks which can also be fitted to mountain bikes.

I'm 5ft6" and now have 165mm cranks. I don't think it makes much difference off road where your moving around on the bike a lot but I do find my knees prefer the shorter cranks on long road sections where essential your in one position for a long time.

london_lady – Member
I am 5ft 3" ish and ride the standard 170mm raceface cranks on the mtb but on my road bike I have 165mm TA vega lite cranks which can also be fitted to mountain bikes.

But can you tell the difference?

Andy, I have similar proportions, and recently fitted 155cm cranks. They're wonderful – no more aching knees, and hill climbing is much easier!

170 or 165's will make a huge difference if she's got short legs for 5'6". With cranks too long you end up with a dead spot and the ride feels like it's tail waging.

I'm 5'7" with 30"inseam. Climb better with 170's but can corner much harder with 165's. 170 is the cheaper option. XT come in 165.