The Cheuh Posted September 4, 2010 Posted September 4, 2010 Is there any remedy for a stripped thread inside a mtb frame where the BB has to screw in?
Wannabe Posted September 4, 2010 Posted September 4, 2010 Yes, take it to a decent Bicycle Workshop, they should have the correct tool to sort it out if its not too bad. Called a "refacing tool", I think.
eggsovereasywithteandtoast Posted September 5, 2010 Posted September 5, 2010 also known as a "BB threading tool" for some reason
Capricorn Posted September 5, 2010 Posted September 5, 2010 it's only the latter. The facing tool is to literally machine the face of the BB to ensure it's properly flat. it has nothing to do with threading.
onetrackmind Posted September 5, 2010 Posted September 5, 2010 The stripped thread was deleted by admin. Apparently not enough pics of bikes.
HeartCoppi Posted September 5, 2010 Posted September 5, 2010 The stripped thread was deleted by admin. Apparently not enough pics of bikes. lol :lol: true to your user name
Johan Bornman Posted September 5, 2010 Posted September 5, 2010 Is there any remedy for a stripped thread inside a mtb frame where the BB has to screw in? Prepare yourself for the worse. If it is properly stripped rather than just cross-threaded, the frame is probably toast. The procedure would be do weld some aluminium inside the BB where the thread used to be. Then to machine it out to what an unthreaded BB would be and then to thread it. The cost involved and the skill required is probably too much.  Give it one attempt by chasing the right tap through there. If that doesn't work, decide what colour your next frame will be.
eggsovereasywithteandtoast Posted September 5, 2010 Posted September 5, 2010 A question that I have is: how did this happen? Is it fairly common?
droo Posted September 7, 2010 Posted September 7, 2010 A question that I have is: how did this happen? Is it fairly common?Usually caused by cross-threading and forcing. I wouldn't say it's common, but it happens. On a road bike you can remachine and retap an English thread to an Italian thread, (JB can correct me here?) but on an MTB you're pretty much toast. Unless you epoxy an external BB cup in there, which *might* work. If you get it straight.
The Cheuh Posted September 8, 2010 Author Posted September 8, 2010 It was simple really. Someone screwed up when they installed the initial BB or they used a crappy frame which already had a stripped thread. I removed the original BB in a frame and there it was.
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