Originally Posted by
Wino Ryder
Derailleurs dont care what shifters you use. The indexing is between the shifters and the rear cogs. For months I ran campy 8-speed indexed DT shifters through a Shimano 600 tri-color rr derailleur with a campy 8-speed Record cassette. It shifted just as fine as my chorus 8-speed derailleur I eventually got. The shifters dictate the amount of cable pull, not the derailleur. As long as the shifters match the cassette you can use almost any derailleur that has a barrel adjuster to fine tune the indexing.
I tend to disagree. Anyone who's tried to navigate Syncro with it's different inserts would find that you also have to match the RD.
Also, my 8-sp DT shifters (Shimano) do not work with my 9-sp 105 RD (Shimano) The first two and last two cogs are fine, the rest do not match up. I've also tried a pre-Ergo RD with 8-sp Ergos, and it did not work.
SRAM, with it's newer 1:1 ratio, addresses this directly.
That being said, I ran an 8-sp Campy rear wheel with 600 STI's for a year or so, with no problem, but the shifters and RD were matched.
If all RD's moved the same amount of lateral distance for equal cable pull distance, they'd all play nice. I sure wish they would, but they don't.