Phill P said:how does this work when sram has a different cable pull requirement to shimano and campy, and because of spacing and rear geometry shimano and campy don't work together.
Au contraire, mon ami ... 10-speed Campy shifters work very well with Shimano drivetrains ... 8-and-9-speed.
And, my previous reckoning was that the 10-speed Campagnolo shifter should be able to mate with a 10-speed Shimano shifter to index with a 10-speed Shimano cassette IF the rear derailleur cable were hooked up using the hubbub.com alternate anchor position which was originally described to allow a 10-speed Campagnolo shifter to mate with a 9-speed Shimano rear derailleur & cassette.
So, based on Zinn's demonstration, I presume that the attachment point for the SRAM rear derailleur, directly-or-modified, equates to the 10-speed Shimano rear derailleur with the hubbub.com attachment.
Phill P said:front is easy, campy have the best design here, works with anything.
Yes.
Phill P said:rear the brifter would pull too much cable surely!
I would have thought the same thing (and, I certainly had zero-intention of buying a SRAM rear derailleur to find out its limitations), but APPARENTLY NOT!