Shimano GRX RD-RX817 Di2 Rear Derailleur – 11-Speed, Shadow Plus, Direct Mount, 11-40/42T

The Shimano GRX RD-RX817 Di2 Rear Derailleur is built for gravel and adventure riders who demand reliable shifting performance in the toughest conditions. Featuring Shimano’s electronic Di2 technology, it delivers precise and consistent shifts across an 11-speed drivetrain. With Shadow Plus clutch stabilization, it keeps the chain quiet and secure over rough terrain. Designed for direct mount installation, the RD-RX817 supports wide-range 1x drivetrains with 11-40T or 11-42T cassettes.

Why you’ll like it

• Di2 electronic shifting – instant, precise, and reliable gear changes.
• Shadow Plus clutch – reduces chain slap and improves chain retention on rough terrain.
• Wide-range compatibility – designed for use with 11-40T and 11-42T cassettes.
• Direct mount – secure and clean frame interface.
• Gravel-specific design – tuned for stability and performance in mixed conditions.

What’s in the box

• 1 × Shimano GRX RD-RX817 Di2 Rear Derailleur (11-speed, direct mount)

Tech specs

Fit notes

• For use with Shimano GRX Di2 1x 11-speed drivetrains.
• Compatible with 11-40T and 11-42T cassettes only.
• Requires Di2 wiring and shifters (sold separately).
• Direct mount frames only – check compatibility before installation.