Originally Posted by
cny-bikeman
I don't see how the crank length formula is terribly helpful though, as that corresponds to about a 5mm difference between .21 and .216.
Are your cranks within that 5mm range? The range reflects anatomical diversity. More importantly, aside from 167.5 and 172.5, how may times do you find cranks in 2.5mm increments?
My wife is short, and prefers a lower cadence than I. Our tandem dealer suggested slightly shorter cranks for her to help "equalize" the cadence difference (170 vs. 165mm). The equation suggested that she be on 144-148mm cranks; when we put her on 150mm cranks it was a whole new world.