The prices I have found for new 10spd Record rear mechs are more expensive than new Record 11spd rear mechs. So...has anyone experienced any compatability issues with running 10spd Record Ergo (with 10spd cassette) with an 11spd rear mech? Is space between the deraillieur inner and out plates narrower that running a 10spd chain would be an issue?

-j

The internet consensus is that you can run 11-speed mechs with 10-speed cogs and cranks. I have no experience doing this. Try it and report back.

I've tried it and it does work, but the 11 speed RD does have a slightly larger actuation ratio that creates a little more travel than needed. It's so small that the limit screw will take care of the problem at either end.

I don't know where you are looking to buy, but prices are still a lot lower from places like Ribble in the UK, even with the unfavorable exchange rates.

Avoid buying any Centaur or lower RD from '07-08. Those may have weak return springs that are not compatible with the new ultrashift shifters, if you were to upgrade shifters at some point.

Thank you both for your responses. I have a project build that will be all campy record. I have everything except for the rear mech, chain, hbar, and stem.

-j