Removing stuck alu BB cup from alu frame

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  • it's doable, thank god

    when you encounter an alu bb cup with a f#cked up outside ring, stuck inside the bb shell of an alu* frame - like this deceased (brutally murdered, actually) dura ace unit, you could try the following:

    • get a sharp metal pin that you can put a decent size hammer to
    • knock out the bearing shell from the outside > inside of bb shell
    • break out a fine hacksaw
    • cut the bb shell; make sure to stay clear of the threads
    • cut again, at 1/3" from the 1st cut
    • use a screwdriver from the other side of bb shell to lever the middle part out (put something round, made of steel covered by at least 2 layers of cloth between lever and cup on inside of bb shell, so as not to damage threads)
    • if necessary, cut once more, opposite the former 2 cuts
    • knock on the outside edge of the cup ring towards centre of bb shell, from right next to both the 1st 2 cuts
    • it will come out by scewing it loose if you haven't deformed it so much that it has dropped out already
    • hey presto!

    good luck!

    sincerely, your amateur technician/butcher peter v

    • steel frame/alu bb cups: torch it :)
  • SAdly it doesn't work with Campy Veloce/Mirage or Shimano UN or cheap BB's where you can't really pull out the axle...! :(

    Nice job tho ;)

  • Thread revival!

    I am going to give this a go as Im part way there having cut a slow in already, just need to follow up after seeing this and gaining a sliver of hope.

    Sidenote anyway, I have a Campag Veloce BB and you can remove the BB internals including axle/spindle etc by taking one side off (Ive only tried with non-drive side removed) and giving the axle on the other side a hard whack with a hammer. It was only a push fit into the remaining cup, although very tight so it took a number of sharp hits to free it up.

    PS if you try that and bend your frame or something don't blame me, just passing on what happened!

  • Just to add my two-penny-worth. Might help someone in the future:
    Shimano UN54 BB in an Alloy frame -
    been on for several years & when it got crunchy I couldn't get the fucker off.
    Tried plenty of Plusgas & eventually bent my wife's extending wheel brace. So bought a 27" long breaker bar to add leverage but it still wouldn't shift. By now the thought of ruining the paintwork using a blowtorch seemed like the only option, then I read online someone using hot water ...
    One kettle of water later & a lot of 27" long breaker bar leverage & the fucker moved!!!!! Can't put in words the joy this gave me!

  • I've still got my BB stuck into the marin frame.....suppose the boiling water expanded the frame and gave the BB shell a bit of breathing space?
    I don't care about the paintwork, might just get a blow torch out, and I could really do with a hack bike too

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Removing stuck alu BB cup from alu frame

Posted by Avatar for peter_v @peter_v