Quote Originally Posted by arielmoon View Post
It says 172.5.

I am 5'7. 31" inseam. Plugged into that formula puts me at 169.88.

Very interesting info! Thanks for the link!

My bf's 5'7 - he's got a 33 inch inseam. He uses 170 cranks. He definitely doesn't like 172.5 cranks. He can use 165's, but prefers 170 because he's used to mountain biking.

Too long of cranks will definitely stress your knees - Pay attention to the angles your knees make when you're pedaling - does your knee come above the horizontal, things like that.