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  1. #1
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    Cracked BB Shell

    There is a small crack in my non drive side BB shell. Its just a Shimano plastic one. Does anyone know how this could have happened? Also, can I buy a replacement or do I need to replace the whole BB? If I can get a replacement should I get a metal one? I think this may be the source of the creaking in my cranks.

    Thanks

  2. #2
    yo yo yo yo yo
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    perhaps you cranked it down too hard and it opened up over time.
    if you can find a replacement cup go for it but i don't know where you would find one - i'm pretty sure they are all the same for the UN's..
    Quote Originally Posted by tx_what_it_do View Post
    machined are for brakes. non-machined are more for brakeless.

  3. #3
    Senior Member mihlbach's Avatar
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    Quote Originally Posted by c0rpse View Post
    There is a small crack in my non drive side BB shell. Its just a Shimano plastic one. Does anyone know how this could have happened? Also, can I buy a replacement or do I need to replace the whole BB? If I can get a replacement should I get a metal one? I think this may be the source of the creaking in my cranks.

    Thanks

    Your LBS should have a replacement cup. Generally those plastic cups are trouble free, although they occasionally crack. If the cracked cup was the source of the creak, the only way to find out is to install another one and see if that solves it.

  4. #4
    Team Beer Cynikal's Avatar
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    I save the metal ones from the old BB's and use then instead of the plastic ones.
    I'm not one for fawning over bicycles, but I do believe that our bikes communicate with us, and what this bike is saying is, "You're an idiot." BikeSnobNYC

  5. #5
    cab horn
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    Which is completle unecessary if a decent mechanic installed it. The reason the plastic cups were introduced were to PREVENT noises.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  6. #6
    cab horn
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    Quote Originally Posted by c0rpse View Post
    There is a small crack in my non drive side BB shell. Its just a Shimano plastic one. Does anyone know how this could have happened? Also, can I buy a replacement or do I need to replace the whole BB? If I can get a replacement should I get a metal one? I think this may be the source of the creaking in my cranks.

    Thanks
    I wouldn't bother. Crack could've been from over-torquing or external damage.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  7. #7
    yo yo yo yo yo
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    Quote Originally Posted by operator View Post
    Which is completle unecessary if a decent mechanic installed it. The reason the plastic cups were introduced were to PREVENT noises.
    source needed
    Quote Originally Posted by tx_what_it_do View Post
    machined are for brakes. non-machined are more for brakeless.

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