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Newbie Crankset Sizing Question(2 posts)

Newbie Crankset Sizing QuestionPeter
Aug 6, 2001 5:42 AM
I'm trying to learn about bike parts and I see that cranksets come in different sizes (170mm, 175mm, etc.) How do you tell what size is appropriate for you? Thanks..
re: Newbie Crankset Sizing QuestionJay H
Aug 6, 2001 5:52 AM
I am about 5'4" and use 170mm sized cranks, one way to gauge what kind of crank size to use is to figure out your bike's "BB to ground" length. Obviously a longer crank on a small bike with say a 70mm length from BB to ground (center of BB to ground) would have clearence problems if you pedal around corners. Generally, the greater the inseam of the rider, the longer the cranks but it could also matter whether you are a spinner or a masher. A spinner likes to spin high cadences (revolutions of the crank) while a masher will spin less but push higher gears. A spinner might like a slightly shorter crank to make it easier to spin while a masher who is a sprinter might want a longer crank to get more torque per revolution.

Ask yourself if you like to pedal around corners or not. Most bikes that are not custom will default to a length that is appropriate to your height. I.e. smaller bikes will come with shorter cranks and taller bikes will come with longer cranks. Check out a bike shop and look at the various cranks (usually imprinted on the back of the crank leg as to it's length) and go from there.