Originally Posted by
Shilun
The threads of the built-in derailleur hanger on my 1980s steel frame appear to have stripped, such that it's impossible to get the RD in tightly except at a slight angle. What's the best way forward from here. I was thinking of grinding off the hanger and replacing it with an adaptor. Does that sound reasonable?
replacing it with an adaptor is certainly a solution. if you can thread the derailer in all the way and have it be secure, you might also be able to "straighten" the hanger with the proper tool (park tool DAG-1). i put it in quotation marks because it wouldn't actually be straight, you'd only be aligning the threads of the hanger with the cassette.
if you can't thread the derailer in all the way, then you might have enough good threads chase the cross threaded section.