Hi there-
I have a 12-25 Campy rear cassette w/Campy Chorus rear der (not the carbon one). Recently it seems that when I am in the 39/25, the top pulley cage is rubbing against the teeth of the cogset. This has never happened before, and I'm wondering why it is now. Any thoughts? Any way to remedy this? It makes an awful crunching noise...

Thanks
BRI