Usually not a problem if you can get the fixed cup out. Obtain a 16mm bolt and nuts. The bolt needs to be long enough that when you run the nut up tight to the end of the threads, the bolt head will protrude from the bottom bracket when you insert it through the bracket to the inside of the stuck adjustable cup. Run a nut up the protruding thread against the outside of the stuck cup, tighten it all up to a huge extent so that it grips the cup securely enough that when you turn the bolt it takes the cup with it. Unfortunately, you may find that the threads in the aluminum suffer (I have only done this with a steel BB) in the way that aluminum crank threads often suffer when a seized pedal has to be forcibly unscrewed. Maybe someone can suggest a penetrant that will ease the sticking and reduce damage to the threads.
That has worked for me, but I have always wondered whether as a last resort one could have a rod arc welded to the cup and use that as a lever. The chrome on the cup would have to be removed first and you would need a competent welder who could do the job quickly without putting a massive amount of heat into it. Does anyone see a problem with that, other than wrecking the paint? (Assuming you are trying to save the frame rather than the cup). The heat might even help unsticking the cup.
I don't think any pin spanner will do the job - the pins will just shear off.
Hugh Thornton
Cheshire, England
From: Robert D. Dayton,Jr. <rdayton@carolina.rr.com> Subject: [CR] Stuck Adjustable cup To: Classicrendezvous@bikelist.org Date: Wednesday, 19 August, 2009, 11:45 AM
Seems no LBS has tools to deal with internal cup/cone BB anymore.
Anyway I have a frame with a stuck Adjustable cup. Aluminum frame and chrome cup.
So does anyone know where I can get a VAR adjustable pin spanner and/or a Stein fixed-cup wrench clamp.
Cheap is appreciated.
Any/all home grown techniques welcomed.
I think if all else fails I can machine something similar to the Stein.
Rob Dayton
Charlotte,NC
USA