Does any one know if you can run 10 sp. cassette and shifters with 9sp. derailuers and cranksets?
I want the extra gear but don’t what to change out everything.
The Derailleurs are compatible from 8-10 speed, because the width of the cassette hub is identical (total distance that the derrailleur has to travel through is the same). The crankset does not need to be changed. Theoretically the chainrings should be narrower, but this is negligible. When I see FSA offer different chainrings for 9 and 10 speed, then perhaps, but given that the same chainrings are used for 8-9-10 speed, you don’t need to change chainrings.