Join Date: Nov 2008
Location: Hollister, CA
Bikes: Volagi, daVinci Joint Venture
There are two or three recent threads (one a resurrected zombie) on this very issue. If you search for Tandemgeek's posts you'll hit these threads for sure. The Shiftmates do work, but can be a bit finicky. On my daVinci I had a very short distance between the chainstay cable stop the my Deore RD so I never got the shifting with Shiftmate where I wanted it. I wound up with a 10 speed SRAM X.9 RD (Exact Actuation), 10 speed Shimano 11-32 cassette and Campy Chorus 10 speed brifters. This combination shifts flawlessly.
Be advised, however, that when I tried a 12-28 10-speed SRAM cassette I could not get the shifting to work well at all despite conventional wisdom which considers SRAM and Shimano 10 speed cassettes interchangeable. If you're content to stick with Shimano 10 speed MTB cassettes (e.g., M771) I wouldn't hesitate to go with the SRAM RD and ship the Shiftmate.