M21 rear derailleurs are designed to work with 6- and 7-speed Shimano road and mountain shifters. Enjoy the wide variety of bikes you can get going again with M21 rear derailleurs.
- Robust composite and steel construction
- Compatible with Shimano 6- and 7-speed mountain and road systems
|Short Cage / Black / 6 – 7-speed||04710495436388||RD-M21SS||MIC71114839E|
|Long Cage / Black / 6 – 7-speed||04710495436340||RD-M21L|