This
B-axle assembly rebuilds the attachment point between your
Ultegra 6800 and
6870 Di2 rear derailleur and your frame. Included with this kit is a new B-limit screw and holder, a commonly stripped out part.
- OEM Shimano part
- For Ultegra 6800 and 6870 rear derailleurs
- Includes B-axle, Spring, B-limit assembly, C-clip and seals