With a built-in chain stabilisation mechanism developed for MTB groupsets, the Shimano GRX rear derailleur offers quiet operation and highly precise gear changes, whatever the terrain. This Shadow+ system features an On/Off lever that allows you to easily unlock the derailleur when riding on the road, making the drivetrain feel just like a road groupset.The RD-RX815 DI2 rear derailleur offers digital precision gear shifting and also benefits from the Shimano Synchro-Shift synchronised gear shifting system.This derailleur is compatible with road cassettes with a maximum sprocket size of 34 teeth.The Shimano GRX groupset stands out with its specific components for gravel riding, offering ergonomics, optimised gear shifting options, reliability and quiet, stable transmission.Shimano confirms that this is not a reworked version of its road components, but rather a groupset specially adapted to the demands of gravel riding.Finally, the GRX815 rear derailleur is fully compatible with Shimano Ultegra and Dura Ace 11-speed road groupsets. A good alternative for increasing the cassette's tooth capacity up to 34 teeth.

Features:

- Quiet and uninterrupted rear gear shifting on rough terrain
- Compatible with current DUAL CONTROL road levers
- For Di2 road and gravel double chainring drivetrains
- Small sprocket: Max. 11 teeth/Min. 11 teeth min.
- Large sprocket: 34 teeth max./ 30 teeth
- Total capacity: 38 teeth
- Shimano reference: IRDRX815
- Shimano part reference: RD-RX815
- Transmission type: Di2 electric
- Shadow RD+ system