Cranks are a simple lever.
So, if it take 200lbs of force to move the bike 10mph with 200 mm cranks,it will take 400lbs of force to do the same with 100mm cranks.So do the math.
If the pedal is tight to begin with,your going to have to really try to sheer a 1/2-9/16 cromoly bolt with your foot.
Last edited by Booger1; 08-13-10 at 02:31 PM.