The Shimano GRX Di2 RD-RX827-SGS is the flagship 12-speed wireless rear derailleur purpose-built for gravel riding. Offering lightning-quick electronic shifting without a single wire, it's designed for riders who demand drivetrain precision on rough roads, gravel tracks, and everything in between.

Highlights

• Fully wireless Di2: No wires, no connectors — clean installation and reduced maintenance on even the most complex frame routing.
• SHADOW ES chain stabilisation: Evolved dual-spring design delivers higher chain tension and superior chain retention over rough terrain, replacing a traditional clutch with a quieter, more reliable solution.
• Automatic Impact Recovery: The derailleur absorbs rock strikes and impacts, then instantly returns to its correct position — reducing damage risk and keeping you shifting accurately.
• Protected internal battery: The BT-DN320 battery sits inside the derailleur body, shielded from mud, grit, and trail impacts. Easily removable for charging.
• Wide-link, skid-plate construction: A reinforced wide-link structure and skid-plate design add strength and ground clearance for demanding off-road use.
• Broad shifter compatibility: Works with all 12-speed wireless Di2 shifters — GRX, Dura-Ace, Ultegra, 105, XTR, and Deore XT flat-bar models.

Built for Gravel

Shimano engineered the RD-RX827-SGS specifically for the demands of gravel cycling. Its wedge-shaped low-profile body reduces snag risk on trail obstacles, while solid pulleys and a durable aluminium plate construction are built to outlast the harshest conditions. The long SGS cage accommodates up to 51T maximum sprockets with a total chain capacity of 41T, giving you the wide gear range you need for loaded gravel adventures and steep climbs.

Wireless Electronic Precision

As part of Shimano's 12-speed wireless Di2 ecosystem, the RD-RX827-SGS delivers the instant, accurate shifting Di2 is known for — now without any wiring. The system communicates via wireless protocol and is fully compatible with Shimano's E-TUBE PROJECT app for personalised shift settings and battery monitoring.

Compatibility & Fit

For 1x12-speed drivetrains only — not compatible with 2x Di2 systems. Compatible with 12-speed cassettes in the 10–51T range including CS-M9200, CS-M9100/M9101, CS-M8200, CS-M8100, CS-M7100, and CS-M6100. Requires a 12-speed HG chain. Compatible with all Shimano 12-speed wireless Di2 shifters (GRX, Dura-Ace, Ultegra, 105, XTR, Deore XT flat-bar). Battery BT-DN320 sold separately.