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  1. #1
    Weeeeee! creejoh's Avatar
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    Question on using a torch to take out my seized BB cup.

    Hello, I have an insanely seized bottom bracket cup on my bike. I took it to my LBS, they soaked it in some PB penetrating oil, used a special tool, and still couldn't get it out. They told me I should go to a local frame builder and have them torch the bottom bracket shell so it expands and I can get the cup out. The only problem is the NAHBS is around the corner so everyone is super busy for the next few weeks.

    The paint is old and messed up, so I don't care about that. Its an old lugged steel frame and I think they used brass to braze it together... I was thinking about getting a butane torch from the hardware store and just do it myself. I just don't have any experience at all with this stuff.

    I have a couple of questions:

    A) Is this a bad idea? Should I just be patient and wait a couple of weeks?

    B) If I do end up doing it, what equipment should I have besides the torch, wrench, and gloves?

    C) Can you give me some tips for doing it myself?

    Thanks!

  2. #2
    Randomhead
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    ,seems like Sheldon Brown had a home made tool to do this.

  3. #3
    Weeeeee! creejoh's Avatar
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    Quote Originally Posted by unterhausen View Post
    ,seems like Sheldon Brown had a home made tool to do this.
    I am probably going to give that a shot, but the shop used a tool very similar to how Sheldon's works, but not homemade... The cup bent one of the handles to it.... Its definitely seized on there, it may not have been changed in 40 years.

    Thanks for pointing me there though.

  4. #4
    Old fart JohnDThompson's Avatar
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    Quote Originally Posted by creejoh View Post
    I am probably going to give that a shot, but the shop used a tool very similar to how Sheldon's works, but not homemade... The cup bent one of the handles to it.... Its definitely seized on there, it may not have been changed in 40 years.

    Thanks for pointing me there though.
    Do you know the threading? Are you turning it in the right direction?

    If it's a standard 36mm flat fixed cup, use a tool like the Campy 793/A, which should be available at any shop with a Campy tool kit:



    The VAR #30 is more versatile, as it has different jaws to accommodate different cup designs, but not many shops have them.


  5. #5
    Weeeeee! creejoh's Avatar
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    ^ Yes, that is basically the tool the shop used. Theirs was black though and they bent the handle of the tool trying to get the cup out. The BB is standard English threading, and its the fixed cup, so I am absolutely sure both the shop and I have tried turning in the right direction.

    It is fully seized.

    Thanks though. I appreciate it. I think I am going to build the home made Sheldon tool for leverage, and use a butane torch to make the BB shell expand. I was just wondering if anyone could give me any tips with the torch part (or tell me its a bad idea to do it myself), seeing as how I don't want to heat up the cup as well, and I don't want to mess up any of the (brass) brazing.
    Last edited by creejoh; 02-22-09 at 12:14 PM.

  6. #6
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    You may not need to heat the frame, just heat the part, and let it cool. That sometimes works. I had a terribly seized bolt on my serpentine belt tensioner in my truck Eventually I got it loose by shocking the bolt with my stick welder. That got the part super hot. Presumably it expanded then contracted in the socket, and possibly burnt up some goop. End result was the bolt came out.

    Propane torch is probably better. An OA torch is too much heat for most things that don't involve melting metal, and still too much heat for some that do.

    Soaking the part is worth a try. Sometimes it takes several weeks of immersion to soak loose a seized piston, for instance. So a few squirts, and overnight even, are not necessarily the end of the road.

  7. #7
    Insane Bicycle Mechanic Jeff Wills's Avatar
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    Quote Originally Posted by Peterpan1 View Post
    Soaking the part is worth a try. Sometimes it takes several weeks of immersion to soak loose a seized piston, for instance. So a few squirts, and overnight even, are not necessarily the end of the road.
    If you don't want to save the cup, you can cut it up with a carbide hacksaw blade or rod saw. Make several kerfs as close as you dare to the BB shell's threads and then try loosening the pieces with that BB tool. You'll probably want to clean up the threads with a tap afterwards.

    I watched this being done when I was a young apprentice mechanic. A customer had prettied up his old Cinelli by disassembling it and taking it to the chrome shop- 100% chrome-plated. He had neglected to take out the fixed BB cup, though, so we spent many hours trying to remove it. It came down to radical surgery.

    We eventually got this fully-chromed, full-Campy Cinelli running again. Then he had us put rubber-block pedals on it so he could ride it in flip-flops.

    ...

    (You can stop screaming now.)
    Jeff Wills

    All my bikes.

  8. #8
    Randomhead
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    I was also going to suggest heating the cup only. The crud in the threads loosens up when you do that, it's not just the thermal expansion. I have done this on a car with great success. Don't kill the paint if you don't have to.

  9. #9
    Lug
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    When you heat things up you can take a wax candle and run it along the part line. The wax will melt and wick in and help lube things up.
    Justin

  10. #10
    Weeeeee! creejoh's Avatar
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    Ill try heating the cup up then. Aside from using a candle, do you have any tips for when i do that?

    Quote Originally Posted by Jeff Wills View Post
    We eventually got this fully-chromed, full-Campy Cinelli running again. Then he had us put rubber-block pedals on it so he could ride it in flip-flops.

    ...

    (You can stop screaming now.)
    I have stopped screaming but I am still simultaneously crying and throwing up.

    Quote Originally Posted by Lug View Post
    When you heat things up you can take a wax candle and run it along the part line. The wax will melt and wick in and help lube things up.
    Justin
    Does this really work? Sounds interesting...

    Thanks all for the helpful replies so far!
    Last edited by creejoh; 02-23-09 at 01:27 AM.

  11. #11
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    Hey man,
    I'm in the bay area, bring it by my shop if you like. We can heat that thing and give it a shot.

  12. #12
    Senior Member Iowegian's Avatar
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    Quote Originally Posted by unterhausen View Post
    I was also going to suggest heating the cup only. The crud in the threads loosens up when you do that, it's not just the thermal expansion. I have done this on a car with great success. Don't kill the paint if you don't have to.
    +1

    A few other tips if you haven't got it out yet is to use a dead blow hammer and to hold whatever tool you use tight to the cup with some sort of bolt.

  13. #13
    Weeeeee! creejoh's Avatar
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    Thanks everyone for the input! Calikid2006 got it out. Dude pretty much rules.

  14. #14
    aka Tom Reingold noglider's Avatar
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    What kind of frame is it, and is it threaded the way you thought?
    You don't read my signature anyway, do you?

    Tom Reingold, noglider@pobox.com
    Residences: West Village, New York City and High Falls, NY
    Blogs: The Experienced Cyclist; noglider's ride blog

  15. #15
    Weeeeee! creejoh's Avatar
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    It is an old track frame from the '60s (?), not 100% sure what kind. Ill take pictures and hopefully someone can ID it. The shop said it may be a Holdsworth.

    Yes, it was English threaded, fixed cup, drive side, righty-loosey.

  16. #16
    aka Tom Reingold noglider's Avatar
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    I bet it's a beauty. Looking forward to the pictures.
    You don't read my signature anyway, do you?

    Tom Reingold, noglider@pobox.com
    Residences: West Village, New York City and High Falls, NY
    Blogs: The Experienced Cyclist; noglider's ride blog

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