I set about replacing the 22 year old bottom bracket cartridge on my Univega Alpina Pro and went though the usual trials:
Plastic lockring teeth sheared off,
metal shell is well and truly stuck, even the LBS gave up on it for fear of damaging the frame .
I got most of the plastic lockring out with a bit of drilling and an industrial soldering iron, then popped the seals out the shell side and undid the axle lock nut so all the gubbins came out and I'm left with just the shell stuck in the frame.
At this point I realised that all the forum threads I'd read about removing stuck bottom brackets referred to the lock nut being on the non-drive side and the "main shell" being in the drive side, and my shell was in the non-drive (left hand) side. I've checked the exposed threads on the drive side of the frame now the locknut is "removed" and I'm 99.99% certain they're left handed, as you'd expect, so the tube hasn't been put on the frame back to front.
All the pictures of Shimano sealed BBs on t'internet show the shell threads being labelled "->R", so drive side and presumably left handed.
My only conclusion is that it was built on a Friday afternoon and some muppet has driven the shell in on the wrong side using an air powered wrench. Unless Shimano for some totally illogical reason produced a cartridge with a right handed shell in 1993 ?
Is it not unknown for BB cartridges to be sometimes rammed in the wrong side of the frame at the factory?
I'm currently Dremmelling out the shell, it's going to take a while. Then I guess the threads will be totally crackered if they've been mega-crossthreaded so I'll have to trim the tube width down to 70mm and either have it re-threaded "Italian" (although 118mm axle width Italian BBs seem scarce) or use one of those velo-orange threadless BB cartridges (not as "original" but at least I can ride it again, will still need the tube reducing to 70mm or so).
Plastic lockring teeth sheared off,
metal shell is well and truly stuck, even the LBS gave up on it for fear of damaging the frame .
I got most of the plastic lockring out with a bit of drilling and an industrial soldering iron, then popped the seals out the shell side and undid the axle lock nut so all the gubbins came out and I'm left with just the shell stuck in the frame.
At this point I realised that all the forum threads I'd read about removing stuck bottom brackets referred to the lock nut being on the non-drive side and the "main shell" being in the drive side, and my shell was in the non-drive (left hand) side. I've checked the exposed threads on the drive side of the frame now the locknut is "removed" and I'm 99.99% certain they're left handed, as you'd expect, so the tube hasn't been put on the frame back to front.
All the pictures of Shimano sealed BBs on t'internet show the shell threads being labelled "->R", so drive side and presumably left handed.
My only conclusion is that it was built on a Friday afternoon and some muppet has driven the shell in on the wrong side using an air powered wrench. Unless Shimano for some totally illogical reason produced a cartridge with a right handed shell in 1993 ?
Is it not unknown for BB cartridges to be sometimes rammed in the wrong side of the frame at the factory?
I'm currently Dremmelling out the shell, it's going to take a while. Then I guess the threads will be totally crackered if they've been mega-crossthreaded so I'll have to trim the tube width down to 70mm and either have it re-threaded "Italian" (although 118mm axle width Italian BBs seem scarce) or use one of those velo-orange threadless BB cartridges (not as "original" but at least I can ride it again, will still need the tube reducing to 70mm or so).
