BB axle length question

wordnumb
wordnumb Posts: 847
edited December 2008 in MTB workshop & tech
My new cranks arrived from ebayland packaged with a new BB, only problem being that it has a 121mm axle and I use a 118mm. Is it worth adjusting the front mech to accommodate the extra 3mm or will this cause problems? *

BB is an octalink es51, bike is a 2005 Stumpy.

* This is a theoretical question as I don't need to replace the BB at the moment and I have a spare 118mm for when I do.

Comments

  • supersonic
    supersonic Posts: 82,708
    The correct BB depends on the design of the chainset - it may well be that the new chainset and BB will be in the same position as the old one! For a given chainline.

    Some require 110mm, some 130mm, totally depends on the spider design. You will probably need to twealk the mech anyway.
    GT ZASKAR CARBON TEAM

    VOODOO CANZO

    Come and see me at https://www.facebook.com/biketyke/
  • wordnumb
    wordnumb Posts: 847
    Crankset is exactly the same so it's going to throw the chain line out by 1.5mm. Probably.
  • supersonic
    supersonic Posts: 82,708
    Is it an LX? Maybe your frame requires a slightly shorter chainline.

    I have an LX M542 crank and 118mm BB on my Zaskar. I had to file the small chainring as it fouled the frame! Should have used a 121 lol.

    Sounds like either would be fine for you. As long as don't use a 113 or 127 lol, you are in the ball park but just shows can still have probs like I did.
    GT ZASKAR CARBON TEAM

    VOODOO CANZO

    Come and see me at https://www.facebook.com/biketyke/
  • wordnumb
    wordnumb Posts: 847
    supersonic wrote:
    you are in the ball park

    In that case I'll chuck it on and see what happens. Ta.

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