Stripped Bottom Bracket Shell

Discussion in 'Observed Trials Discussion' started by CoppellStereo, Nov 30, 2004.

  1. CoppellStereo

    CoppellStereo Ruff Rider

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    As some of you know my BB shell is stripped on the drive side now, and I was seeing if you guys could give me some ideas on how to get it working again. Some of my ideas were like to weld some beads inside the shell, and shave them down to the right size, and then tap the beads, and another one was to JB Weld my BB on the stripped side. I want this done ASAP so I can ride my new frame!
     
  2. hydroboy

    hydroboy "Jak se mas"

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    I bought my first trials bike complete and the bb was cross threaded in the factory, anyway eventually it got completely stripped out so i glued it in with araldite, worked fine, but if you ever want to get it out its a pain in the arse, you need lots of acetone and possibly a hammer, drill, gear puller, warhead etc.
     

  3. katoom

    katoom New Member

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    Howdy!

    As a last resort, there used to be bottom brackets that did not use the
    threads in the shell. Perhaps there still is. I had a Bridgestone MB-0
    that came with Mavic components and the bottom bracket used lock rings
    that pressed against a taper cut into the shell. As I said, this might
    be a solution only if you got stuck as you'd be saddled with oddball
    bottom brackets for as long as the frame survived.

    Good luck!
     
  4. gononza

    gononza New Member

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    I dont know the full story, but have you tried talking with your LBS about re-tapping the threads? I had a similar issue with an old onza t-raptor being stripped really bad. After re-tapping the BB there was literally hairs of aluminum holding the non drive side bb cup in place, but it worked "long enough for me to break the frame twice anyways". If the poor frame is totally screwed, I've heard jb-weld is the way to go.
     
  5. trauma100

    trauma100 Modest

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    Is this on your new BT?? how did that happen?
     
  6. mikeschiavone

    mikeschiavone Active Member

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    thats really unfortunate to hear.

    call up a local machine shop, and swing by to show them. ask them what they'd recommend, how much it will cost, and also tell them your original ideas for fixing it. keep in mind heat treatments. also, try to get some advice from the welders/machinists on the board. I know tanner and bwagner would probably have good ideas.

    good luck.
     
  7. oicdn

    oicdn Guest

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    ^^ I second that idea. Machine shops, well, any machine shop without doofs in there can knock that out in less than10 minutes......

    I've had cyclinders in my engine completely bored 30 over in less than 5 minutes once it was set into the "jig".
     
  8. DangerousDave

    DangerousDave Active Member

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    how does that happen on a brand new frame out of curiosity?
     
  9. CoppellStereo

    CoppellStereo Ruff Rider

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    the original threads were supposedly crooked (I, and 2 other shops verified that this was true) and so the 2nd shop tried to re-tap it straight, and when they did this, the angle of the other threads and the new ones canceled each other out coming out with no threads.

    but I think i might try to recreate threads with JB Weld, and I will let you know how that goes
     
  10. Tanner

    Tanner New Member

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    Honestly, I'd take it too a good weldor and say "I need a few beads run in my bottom bracket shell." Point it out to them and ask for a TIG weld. The weldor will probably ruin the heattreatment of the BB shell, but honestly, I wouldn't worry about that. Then, once a few beads are run in the stripped BB shell, go to a machine shop, and have the BB shell bored out to the correct diameter, then go to your LBS and get it retapped. It's basically adding metal to the BB shell, in place of the stripped threads.
     
  11. DanBowhers

    DanBowhers I farted.

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    i'd buy a new frame, just kidding, i agree with tanner, under his name it says "welder"
     
  12. gtrials

    gtrials chitfcuk

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    I know this is an old post, but has anyone else heard of what to do in this situation? I am in the same situation and the only option I was offered was to bore the shell larger and then weld in a steel bottom bracket insert. I need to know if anyone else has had beads laid down then retapped. Im really annoyed that I cant ride my new frame. Let me know!
     
  13. Trialsaddict

    Trialsaddict I have no idea.

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    JB weld. worked for me.
     
  14. gtrials

    gtrials chitfcuk

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    Looks like that is the way to go.
     
  15. RomanC

    RomanC Well-Known Member

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    See if you can go the welding route; otherwise, JB will work good unless you weigh a ton and go to bash often.
     
  16. free_rideman

    free_rideman Keepin it real

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    Put in a helicoil. I am pretty sure that would work. Maybe cheaper.
     
  17. gtrials

    gtrials chitfcuk

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    you can helicoil a bottom bracket? wouldnt that enlarge the diameter of the shell?
     
  18. RomanC

    RomanC Well-Known Member

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    Provided you find a helicoil of the right size. I think a welding a small bead and then tapping it would be better.
     
  19. gtrials

    gtrials chitfcuk

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    I think so too, but a frame builder I spoke with didnt think that would work. Have you heard of anyone doing it?
     
  20. RomanC

    RomanC Well-Known Member

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    I think Steve (CoppellStereo) found somebody who could do that. The quote was rather high though $200 or something like that