Originally Posted by rideorglide

I have shorter legs in relation to my torso. My change was for comfort and fit, with no real care about being possibly slower. I figured I would spin faster to compensate, if anything.

I experimented by shifting to 165mm cranks from 170/175 to try a different fit for my legs. The change revolved around comfort. It also allows me to lower the saddle a few millimeters (an insignificant amount for most, but a little more comfortable for me.).

I'm happy with the new bike and cranks and don't have any complaints, but I realize I may have sacrificed some speed/leverage. Knees haven't been complaining, but are they any better, I can't really say.

I think you have to be prepared to lose peed if you go shorter, and maybe have a compelling fit/comfort reason to make the shift.