Originally Posted by
FBinNY
Bend or break there has to be some outside force involved. Which is the point I've been trying to get across since way back in post #12. In post #35 I posited that----
Instead, I suspect that the hanger is not secure and rigid where it's attached. All too often, the mating surfaces either aren't flat, or something is preventing the hanger from pocketing correctly. That allows for it to move slightly throwing the RD off.
It's nice to see that folks are FINALLY considering this. Hopefully the OP can get the hanger properly and rigidly secured to the frame.
I believe I made the same point in my first post in this thread. But the OPs Giant hanger does seem secure, and the Cannondale is not available.
There are definitely some hangers which bend surprisingly easily, and some people that seem blissfully unaware of how much they bang their bikes into things. So far their is no one cause for the OP's problems - mainly because we have no way of testing the previous bike.