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Crank length...(5 posts)

Crank length...jtferraro
Oct 19, 2002 9:46 PM
Hmm...I'm thinking I should go w/172.5mm cranks for my new road bike, as my mtb has 175mm cranks, however, a 58cm TREK comes w/175mm cranks. Don't you think that is on the long side? Naturally, I realize that shorter cranks cater to spinners and larger cranks cater to those who like a slower cadence, but pushing a higher gear. NEway, what size cranks are you on? What is the most common or average length?

re: Crank length...roadcyclist
Oct 20, 2002 3:13 AM
Most common would probably be 170, as that's what manufacturers of low-end bikes use. IMHO, you're right - 175 is too long for a 58cm bike, but I'm sure preferences vary. I ride a 51cm and use 170, and a 50cm with 165 (I'm a proponent of spinning versus mashing). Can you test ride the bike with the 175s?
re: Crank length...bugleboy
Oct 20, 2002 4:39 AM
The standard length crank for a 58cm is 175 on most production bikes. IMO the difference in 172.5 and 175 is slight. You might be better off just working on your spin first then if the desired result isn't there, then consider different length cranks.
I stayed with the 175mmJL
Oct 20, 2002 6:42 AM
cranks when I bought my 58 cm Trek. It was a change from my 170mm on my old bike. I haven't had any problems spinning with the longer cranks, except for a small case of "newbikitis" where I overdid the mileage when I first acquired it :) and hurt my knee. I doubt you'd notice a huge difference with a 2.5 mm shorter crank, but that's my opinion.

There are others that know the "correct" formula, but I think crank length tends to be another personal preference rather than a number in a formula.

Happy riding.

Maybe try to get your shop to swap cranksPODIUMBOUNDdotCA
Oct 20, 2002 1:16 PM
The standard on the road (and probably on your soon to be old road bike) is 172.5 so maybe ask for them to be swapped if it can be done for free. Ultimately though 2.5 mm won't make a huge difference... although the tiny bit more leverage you get might be in your favour if you do a fair ammount of hill climbing.