[C-40]

another possibility....

The spacing difference is only 5%. To make the Campy RD travel less on each shift, moving the cable further away from the clamp bolt to reduce the acutation ratio might be enough. I'd start with something as simple as using a short length of shift cable to act as a spacer to keep the cable away from the bolt.

I've done just the opposite with a 10 speed RD on an 11 speed drivetrain. I grind the clamp bolt threads down to the root of the thread to increase the actuation ratio rather than reduce it.

 

[C-40]

the reason...

Campy shifters pull 2.5mm of cable five times, 3mm twice and 3.5mm twice. The SRAM RD needs a uniform cable pull to work properly. Even with a shiftmate correcting the average pull, it won't be right.