Originally Posted by
iherald
I am running the correct length now, but how do I determine what it is without taking it out?
You can take your cranks off and measure the spindle, i'm assuming it's square taper. Measure your bb shell width while you're at it. You'll also need to determine if it's english/french/italian/other.
Easiest way is to pull the unit. What kind of bike is it again?