Shimano GRX 717 Di2 Wireless Rear Derailleur  At the heart of the system, the GRX RX717 Rear Derailleur offers fully wireless operation with rugged reliability and seamless 12 speed shifting. Designed for gravel and off-road use, it delivers consistent performance even in demanding conditions. Shimano Impact Recovery and Durability Automatic Impact Recovery instantly returns the derailleur to its original position after a knock. The wide link structure and integrated skid plate provide exceptional off-road durability, while SHIMANO SHADOW ES technology ensures superb chain stability and security. A protected battery housing keeps the removable battery safe yet easily accessible for charging. Shimano Battery Compatibility The RX717 uses the same battery as GRX RX827, XTR M9250, DEORE XT M8250 and DEORE M6250, making swaps between bikes straightforward. The rechargeable battery offers a range of 700 to 1,000 kilometres depending on riding conditions. Shimano GRX Extended Features The long cage RD-RX817 SGS version accommodates Shimano 10-51T 12 speed cassettes. Solid pulley construction ensures reliability over time. Paired with the RX715 DUAL CONTROL lever, the system is compatible with Shimano’s E-TUBE app, allowing riders to customise shift speed, button functions and update rear derailleur firmware. Shimano GRX Accessible Gravel Performance The GRX RX717 range combines affordability with Shimano’s Di2 precision, extending high-quality gravel-specific electronic shifting to a wider range of riders, providing a worry-free experience on any terrain.