Shimano GRX RD-RX815 Di2 Rear Derailleur – 11-Speed, 34T Max, Shadow Plus
The Shimano GRX RD-RX815 Di2 Rear Derailleur is designed for gravel, endurance, and mixed-surface
riding. Built specifically for 2x 11-speed GRX Di2 drivetrains, it offers crisp, reliable
electronic shifting and stable chain management. With a 34T maximum low sprocket capacity,
Shadow Plus clutch technology, and a direct mount design, this derailleur ensures smooth, quiet,
and secure performance even over rough terrain.
Why you’ll like it
-
Di2 electronic shifting – fast, precise, and consistent gear changes.
-
Shadow Plus clutch – stabilizes the chain and reduces slap on gravel and trails.
-
34T maximum cassette compatibility – optimized for wide-range 2x gravel setups.
-
Direct mount attachment – secure and clean installation to compatible frames.
-
GRX-specific design – engineered for gravel and adventure riding.
What’s in the box
- 1 × Shimano GRX RD-RX815 Di2 Rear Derailleur (11-speed, Shadow Plus, direct mount)
Tech specs
| Manufacturer |
Shimano |
| Series |
GRX |
| Model |
RD-RX815 |
| Manufacturer Part # |
KRDRX815 |
| Speed |
11-speed |
| Max Cassette Size |
34T |
| Shifting |
Di2 electronic |
| Mount Type |
Direct mount |
| Clutch |
Shadow Plus chain stabilizer |
| Design |
Top-normal |
| Application |
Gravel / Endurance / Mixed-surface riding |
Fit notes
- For Shimano GRX Di2 2x 11-speed drivetrains.
- Compatible with cassettes up to 34T max low sprocket.
- Requires Di2 shifters and wiring (sold separately).
- Direct mount design – confirm frame compatibility before installation.
