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Crank Arm Length(5 posts)

Crank Arm Lengtheltoro
Jun 20, 2002 10:57 AM
Hi, I am a beginner road biker though I have been riding and racing mtn bikes for 12 years. I recently bought a GT ZR-5 65cm for training. I am in the process of upgrading the drivetrain to Ultegra. What is my optimal crank arm length? 165, 170, 172.5 or 175 mm? I am 5'9" and have a 32 inch inseam.

re: Crank Arm LengthJuanmoretime
Jun 20, 2002 12:13 PM
Either you had a typo or your riding a 56 which I would believe to be correct for your height. 172.5 at your height and inseam. You could go longer but it would slow down your cadence.
Here's a linkszybki
Jun 20, 2002 2:28 PM
It requires you to take some PITA measurements, but the results are pretty interesting, and it's data based, not just a rule of thumb.
What data?Kerry
Jun 20, 2002 6:22 PM
Since there's never been a study that truly supported any correlation of body dimensions and crank length, how can this formula be "data based." Anyone familiar with this question knows that there have been studies that supported just about anything, which is pretty much proof that there is no fixed relationship. Crank length is 1) pretty much personal preference and 2) something that most people can adapt to with a little time. Taller people on longer cranks seems to make sense, but there's no formula, rule of thumb, or theory that is actually supported by a valid study. Full stop.
What data?curlybike
Jun 26, 2002 11:48 AM
Did you happen to see the article that Velonews wrote about the testing they did on crank arm length? More confusion at best.