Captain Jake

I was thinking of building a cyclocross bike with campy components, and was wondering if I would be able to use the Centaur shifters with one of the 11 speed rear derailleurs so I could use one of the 29 tooth 10 speed cassettes without having to get the long cage derailleur.

operator

1) Short cage = standard/compact + all campy cogset except 13-29
2) Medium cage = standard/compact + all campy cogsets
3) Medium cage = triple + all campy cogsets except 13-29
4) Long cage = triple = all campy cogsets (special chain length consideration for some rear cog combos)

DaveSSS 

Operator is right for 10 speed RDs. Unless you have some other use for an 11 speed RD, buying a medium cage 10 speed model would be cheaper and work perfectly. I even use a 10 speed medium cage with one of my 11 speed bikes, but I make a small alteration to the RD clamp bolt to increasse the actuation ratio.

The 11 speed RD has a slightly larger actuation ratio, but it will work fine with 10 speed. Only the 2010 models are guaranteed to work with a 29T large cog. Those models have a revised "B" screw mechanism that swings the cage further back to clear the 29T cog. 2009 models can be converted with one cheap part (#5-RD-SR004).

https://beta.aebike.com/Campagnolo-11...on_p_8594.html

Some users manage to combine a short cage 10 speed RD with a 13-29 and get it to work, but how well it works depends on the frame. A longer RD hanger improves the chances of the upper jockey pulley clearing the 29T cog. The prefect chainstay length can add 3T of wrap capacity, compared to a worst case length.

Captain Jake

I was hoping to build the bike to be suitable for touring and therefor have a triple crank in the front. From the sounds of it I'll have to get a long cage derailleur. Thanks for the information.