Crankarm Length

[Toback]

I have on my bike, a Shimano M391, 26-36-48T Crankset, the length of the crankarm is 170mm. Am I able to use a crankset with the arm length of 175mm ? Thankyou

[Nobody]

Yes.

[warthog1]

Yes.

Sorry to the op but the topic has been raised previously.


Some will argue long is better, and some short. You'll find out by trial and error what works for you.
As a generalisation, longer leg = longer crank.

[Nobody]

Yes, the summary of previous threads are:

Longer:
- Slightly faster mechanically in climbing.
- Slightly mechanically faster for TT.
- Has lower gearing effect (more "torquey" feel).

Shorter:
- Less knee problems for some shorter people.
- Faster accelerating.
- Less overlap/clearance issues for toe/heal/ground/leaning.
- Lower TT position, so theoretically faster for some.

Generally shorter is favored for track, longer for road.

In the end, get what suits you, or you like the best. I usually run 165mm on all by bikes, but was temped in the last purchase to change to 170 for my road bike, but they were out of stock. So I'll see how I go with the 165s with lower Q Factor (134mm) and different pedals (Speedplay). I may buy longer cranks next time.