I am still trying to figure out which front der was on my bike when I got it. It has a compact double, and the der is Chorus, but does not match any pic I can find in the Campa catalog or spares manual.

The reason I care is that I can't seem to adjust the interference out of it when I am in 50-13, which seems wierd. It is OK in 34-29. And I can't find out where the rubbing occurs, which is even wierder.

Bottom line to me is that with a compact, selecting the front der needs careful attention.