Originally Posted by
AlmostTrick
My newest road bike came with 175's. I hated them. Felt very "choppy" when I got up to my favored cadence. Switched it to 170's and I was smooth and happy. But on the cruiser and mountain bikes I typically don't spin as fast, so the extra torque works works well with a slightly higher gear.
Gearing and crank length are very personal things. Everyone's gotta experiment a bit and see what works for them.
I'm about 6' (just barely over), and have a long inseam for my height at about 33.5". I can run a pretty wide variety without any negative effect so far.
I run 170s for most of my riding - old road bike with 3 speed for commuting (~20km each way) anrad tootling around with the kids. I've got 175s on my current TT build, almost more as a test than anything else. I'm not sure about it, I might go shorter, but it seems to be fine.
My 20" race bike I have 185s - I think they're just a touch long for me. I have 180s on my cruiser, and I think I'm going to switch my class bike down to 180s as well. The 20" I bought from a guy 2-3" taller than me.