Crank arm legnth

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Re: Crank arm legnth

Postby amadkins » June 12th, 2013, 5:50 pm

Laser4G63 wrote:I was using 175mm arm length, but since switched to 170mm. I supposed it may have a lot to do with the type of rider you are, whether you mash or spin. I am a spinner and notice I can do so better with the 170s. I know 5mm isn't much, but it's working for me. I am 5'11", btw.

This for me as well. I'm long in the torso tho. I found 175s hurt the front of my knees on long rides.
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Re: Crank arm legnth

Postby jiml » June 12th, 2013, 7:49 pm

Hey bax,

I ran 180's back in the day as well, but on the 20/24", you're mostly standing and sprinting from corner to corner. Good leverage for out of the gate and accelerating quickly out of the turns, but I dunno if I'd want to be spinning those long cranks while sitting in the saddle for long stretches when you want to get a good ankle whip going. Just food for thought, as I've pondered this question as well. YMMV.

My guess is the knee pain is the extreme flexion/extension at the top (12/6 o'clock) of the stroke due to the longer cranks, if you don't have the bone length. Again, prolly not too much of a deal while standing but the saddle time is what kills it.

You ran a gear other than 44x16? 8)


btw, I'm ~5' 10" /* edit - and run 175mm on my 26/29" bikes */
Last edited by jiml on June 12th, 2013, 8:43 pm, edited 1 time in total.
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Re: Crank arm legnth

Postby MediumRB » June 12th, 2013, 8:31 pm

I'm 5'8" with 30" inseam. I spin more than I mash, so narrow tread and 170mm crank arms for me.
Everything I ride makes sense.
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Re: Crank arm legnth

Postby iamkickstand » June 12th, 2013, 8:56 pm

165mm on the DH bike, I think 170 on the xc bike
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