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  1. #1
    custom bloke's Avatar
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    B-screw adjustment on Shimano rear derailleur

    I know it should adjust the derailleur body angle, but whichever way I turn it nothing happens.

  2. #2
    Pwnerer Wordbiker's Avatar
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    Quote Originally Posted by ahsposo View Post
    Ski, bike and wish I was gay.

  3. #3
    Small Member maddmaxx's Avatar
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    The b screw is a dynamic adjustment. It works with the preload of the spring in the derailleur mount to ballance the fore/aft angle of the derailleur against the tension of the chain when peddling. To see the results of the adjustment you need to have the bike on with the drive train moving. If the b screw is contacting the notch on the derailleur hanger, you can observe the adjustment by watching the gap between the top jockey wheel and the cassette cogs increase (b screw in) or decrease (b screw out). If nothing seems to decrease the gap, your chain may be too long. If you cannot get away from the cogs, then you may not have the proper derailleur for the size of the cogset.

    Sometimes when installing a derailleur, the b screw is pinched against the side of the derailleur hanger instead of set into the notch. This will result in improper adjustment and or a bent b screw.

  4. #4
    Senior Member charly17201's Avatar
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    Thanks for the link... I've book marked it for my use
    Peace. It does not mean to be in a place where there is no noise, trouble or hard work. It means to be in the midst of those things and still be calm.

    In response to bicycling being so dangerous: "We could all died today from any number of accidents. I'm not going to stop living to keep from dying." The Northern Tier by Lief Carlsen

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