Old 05-25-15 | 11:33 AM
  #8  
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IthaDan
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From: Ithaca, NY

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^^^ 24mm will work. Trek's BB90 size takes a standard gxp spindle, which is 24mm on the drive side and 22mm on the NDS. Your cranks would work fine with the OP's son's frame and existing bottom bracket.

Originally Posted by rpenmanparker
Here ya go: SRAM Force Road Crankset 175mm x 53 39T GXP No BB | eBay

Bikewagon is a reputable seller on ebay or direct. You can go to their site if you like. Call them to be sure the spindle is a match for the BB, but I think it is right.
Re-read the OP, he already has those cranks, he's looking for compact gearing, so something like this-

SRAM Force GXP Crankset - 2013 | TotalCycling.com

Or these- http://www.bikewagon.com/sram-rival-...t-50-34t-black

Last edited by IthaDan; 05-25-15 at 11:37 AM.
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