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Bottom BB sizing

Discussion in 'Bicycle Mechanics and Repairs' started by bianco, 17 Jan 2008.

  1. bianco

    bianco New Member

    Hi guys

    Bought a new crankset, and a new BB.

    Guy at chain reaction sarcastically informed me I needed a 109mm spindle length. The sarcasm indicated it could be any other fit.

    The chain rubs the outer chainring on the highest 2 gears, should I get a 113mm spindle length to compensate?
  2. Smokin Joe

    Smokin Joe Legendary Member

    They all do that, John.

    The chain is running out of line when you are on the smallest ring and the smaller sprockets, it is not a combination that you should use. In any case you will be able to get near enough to those ratios with the big ring and a couple of the larger sprockets.
  3. bianco

    bianco New Member

    It didn't on my previous crankset, and it's only a double
  4. TheDoctor

    TheDoctor Man-Machine Staff Member

    What chainset is it?
  5. bianco

    bianco New Member

    Ritchey WCS Road V Double - octalink fitting
  6. TheDoctor

    TheDoctor Man-Machine Staff Member

    Pretty sure octalinks only come in 2 lengths - one for a double and one for a triple.
    Maybe the BB on your last crankset was a bit too long? Little ring / little sprocket combinations are always bad, and always avoidable, like Smokin Joe said.
  7. Monty Dog

    Monty Dog New Member

    There is only one Octalink BB length for a double - 109mm. Chainrub is a common affliction of modern drivetrains - if you find you need to be in the smaller sprockets, shift to the big chainring.
  8. bianco

    bianco New Member

    Cheers Monty Dog, a little annoying thats all.

    I used to be able to use all sprockets on either chainring, must be something I need to get used to!
  9. fossyant

    fossyant Ride It Like You Stole It!

    South Manchester
    Nothing to worry about - I can't use the bottom two sprockets when in my small chain ring, plus, as had been said, the chain is running at a poor angle.
  10. bobg

    bobg Über Member

    Crosby Merseyside
    Might a 10 speed chain help? that tiny bit less width cured the irritating run I had on the rear mech. Just a thought...