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front derailleur : best to get get a 34.9mm or 31.8/34.9mm

mungojerry31mungojerry31 Posts: 12
edited December 2012 in MTB buying advice
I have a 2008 Trek 6300 post size is 34.9MM I know both will work, but I didn't know if there was any advantage in using one size over the other. I'm looking to buy a Shimano XT M771 Conventional 9sp Front Mech. Thanks in advance for any help.


  • njee20njee20 Posts: 9,613
    They're all 34.9, you can fit a shim to make it 31.8.
  • THanks! Figured that was the case but didn't want to order something and find out I would have been better off going with one over the other.
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