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Why only 175 crankarm length?

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Why only 175 crankarm length?

Old 07-26-20, 07:30 AM
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bent4me
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Why only 175 crankarm length?

I am 5'7" and prefer 170 crankarm length yet the standard is 175 on mountain bikes.
I'm looking to by a new bike with shorter cranks and prefer not to custom build. Anybody make a inexpensive 1X with shorter cranks?

Last edited by bent4me; 07-26-20 at 07:34 AM.
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Old 07-26-20, 08:19 AM
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Salsa puts 170ís on smalls and some mediums
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Old 07-26-20, 01:55 PM
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The good news is that part resale prices for new-take-offs is pretty good, and the swapout is pretty easy for most crankset makes.

So.. it sucks that you can't find what you want in a stock bike, but you can do the conversion for little cost and effort, and get exactly what you want.

Edit to add: Not sure what your price range is, but I'm compelled by the Praxis Cadet and Girder. The later comes in hollow AL or solid carbon to suit most tastes. The Lyft is a hollow carbon, if you're extra spendy and like nice things. They're all available in 170mm.

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Old 07-26-20, 04:02 PM
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Out of curiosity, I pulled up the specs on a Specialized Fuse mtn.bike, just to look at some specs. The crank length on all but the XL size is 170. This just happened to be the first I pulled up, and didn't go further, but appears they're out there. https://www.specialized.com/us/en/fuse-27-5/p/171070?color=263341-171070&searchText=96020-7001
Wanted to see if Ijust lucked out, so went to Trek's site--their Marlin 7 had 170 cranks on their small and medium.
(2 spd crank tho)
Another is Giant Fathom-is a single speed crank, and according to Giant's site, the small (which they say should fit up to 5'8") has a 170 crank. I only pulled up a few hardtails, but maybe you're just not looking in the right places? I couldn't figure that the mfrs would only offer 175's on their smaller framesets.

Last edited by freeranger; 07-26-20 at 04:40 PM.
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Old 07-29-20, 11:40 AM
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Intense uses 170 mm cranks on all sizes of the Primer 29 + 27.5.
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Old 08-06-20, 06:01 PM
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I'm on 165's now on my AM hardtail. Love it! 5'9" w/34" inseam for reference. I've seen a number of other posts mentioning many manufacturers moving to shorter cranks on production bikes. Especially with modern geo bikes with lower bottom brackets.
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Old 08-07-20, 11:46 AM
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I have 170mm cranks on the road bike and 175 on the mountain bike and don't notice the difference when pedalling. A 175mm crack however should have some torque advantage when climbing, which I suppose is useful on a mountain bike.
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Old 08-14-20, 06:19 AM
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This bugs me, too, but I suppose it's just cheaper for manufacturers to put 175's on everything. I use 165's on road bikes and 170's on mountain bikes. When I changed from 175 to 165 on road, it made a big difference in comfort. Not sure the 175 to 170 has been as important on the mountain bikes, but it helps. I've just bought the crank arms I wanted and swapped them out. I wouldn't even waste my time trying to find a prebuilt with what I want.
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