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  1. #1
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    Shimano Chainring on Bontrager Crankset

    I just purchased a Shimano XT chainring to put on a bontrager race crankset (it was the only one my local bike shop had). It's a 32 tooth middle ring and they are both 4 bolt pattern with 104 BCD. the shimano ring doesn't quite fit though. the holes line up perfectly but the part of the ring that goes around the bolt holes is slightly more substantial on the Shimano ring and thus it doesn't fit flush against the spider. Has anyone experienced this problem? I was thinking of just filing down the shimano ring to make it fit. anyone tried this? it's not about the money. i'm not that cheap, but i live in Alaska and waiting for a different chainring to arrive might take a few weeks and i want to ride now. any advice would be very helpful.

  2. #2
    Former Bike Wrench
    Reputation: mtnbiker72's Avatar
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    Yep...Shimano chainrings do not fit Truvativ, Bontrager, and Race Face crancksets because of the problem you are experiencing. However, I have been using an XT ring on my RF cranks for over a year now by simply using a Dremol tool to grind down the extra material on the chainring. Works fine, there is plenty of extra material so it won't weaken anything.
    Last edited by mtnbiker72; 06-11-2007 at 01:13 PM.

  3. #3
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    I'm using LX middle and grany rings on a Bontrager race X-lite crank with no problems.

  4. #4
    mountain biker
    Reputation: slyfink's Avatar
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    I'm having a similar compatibility problems with XT and Hone rings... I just bought a Hone crankset to replace my XT crankset. I wanted to keep my XT rings on the Hone cranks and keep the Hone rings for when the old ones would wear out. But the XT granny ring won't fit on the Hone crankset for the same reasons you described. I'm thinking it's actually a new standard thing; that Shimano may have changed the standard for some reason...

    If anybody could shed some light on this, I'd appreciate it...

    thanks, and happy trails!
    continuous growth is the strategy of a cancer cell.

  5. #5
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    Modify middle Shimano chainring to fit Bontrager crank

    I also successfully modified a Shimano center ring to fit my Bontrager crank. The outer and inner rings fit no problem but the center ring had a little too much 'meat' on the ends of the inner tabs to sit properly in the spider. Using my old center ring as a template, I filed off about 1/16" off the end of each each tab on the ring. Then it fit properly.

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