Bottom Bracket

[ian emmerson]

I appear to have damaged the threads on the frame whilst tightening a loose bottom bracket.
Thread is still visible although not enough for the retainer to be tightened correctly.
Can this be repaired or is the frame a write off ?

 

[Tim Hall]

In similar circumstances I was able to add a spacer to the fixed side and screw the adjustable side in a bit further, so it was past the damaged threads. This assumes that the damaged threads are on the adjustable cup side, obviously.

 

[Scotchlovingcylist]

Threadless bottom brackets are a solution also however I believe the quality of them can vary

 

[400bhp]

You should be able to get the thread re-tapped.

 

[RebornBumbler]

You have a few options:

Fit one of the threadless BBs (generally only square taper)
Have a framebuilder hack off the shell and fit a replacement (steel only I'd suggest, and not likely to be cheap)
Have a helicoil fitted (assuming one is available) or have a threaded sleeve inserted and subsequently tapped (much the same thing)

Simply running a tap through the existing damaged thread is unlikely to be of much use, unless material is somehow added first.

 

[Tim Hall]

I think a frame builder would slot the existing shell, braze it up, giving a reduced diameter, then retap, rather than replace the whole shell.

 

[Tojo]

I appear to have damaged the threads on the frame whilst tightening a loose bottom bracket.
Thread is still visible although not enough for the retainer to be tightened correctly.
Can this be repaired or is the frame a write off ?

Where a bouts are you, I have a English and Italian bb thread chasing tool, if you're not anywhere near Newcastle take it down to your lbs they should be able to chase the threads up as long as they are not totally striped out......

 

[ian emmerson]

Thanks everyone for your advice ,
it's with my LBS now , so hopefully can be sorted

 

[midlife]

Just out of curiosity what frame is it ?

Tim is right for my era, back in the 70's we would have cut the BB shell, closed it together with a slightly small diameter and retapped.

There were a few oversize BB cups we could use if we recut the threads oversize....

Shaun

 

[PhilDawson8270]

Check local engineering firms, they may be able to do a thread repair cheaper than a bike shop