Campag rear

[KM2]

Will a centaur 10 speed rear mechanism operate on an 11 speed cassette with the appropriate lever?

[hamster]

Yes but. The leverage hasn't changed but IIRC the spring tensions are much higher in modern mechs, presumably to overcome cable sticking. So you may find it works, but not well.

[mattsccm]

Back a bit when they changed to 9 speed, I think, or maybe 10 speed thinking about it, using the alter stronger sprung mechs could give the plastic bits of the levers a hard time resulting in excess wear. .
There is a Campag group on Facebook that will give you the answer from one of the UK service centers.

[KM2]

Thanks