Can't remove rear derailleur

zhang

I'm trying to get my rear derailleur (shimano 2200) off to service/replace it. The top pivot (I think they call it the B-pivot?) is seized and won't more freely, which is giving me problems. The problem is, when I use the allen key to loosen the derailleur mounting bolt it moves about 1/3 turn and then won't budget. I'm concerned that if I put any more pressure on it the derailleur hanger will bend!

https://dl.dropbox.com/u/867382/Photo%2 ... 3%2001.jpg
https://dl.dropbox.com/u/867382/Photo%2 ... 3%2021.jpg

So that's pretty much what happens when I turn the allen key.

Any ideas guys?

Monty Dog

I't unlikely you can exert enough force through a regular allen key to damage the gear hanger - probably some light corrosion on the threads of the mounting bolt. Remove the rear wheel and spray some WD40 or GT85 on the threads, let it soak and try again.