Ready to take on any challenge, the RX817 features an adjustable chain stabiliser which prevents chain slapping and drops. Shimano has also included a switch stabiliser which can be set to on/off to match the terrain conditions, which allows you more freedom to explore the unknown. Whether you're planning a new adventure or joining friends after work for a ride out, this superb model's gravel-tuned clutch makes gear changing a breeze in any situation. Inspired by off-road groupsets, you'll enjoy its silent and uninterrupted rear shifting on harsher terrain conditions, where most common systems would fail. Smooth and reliable, this rear derailleur features some of the finest technologies to keep you riding at the top of your game. Its revolutionary Di2 shifting system solves many of the challenges that mechanical systems face with the use of state-of-the-art electronics. This technology gives you instant, accurate and lightning-fast shifts every time you ride, at the push of a button. You'll also be able to change gear when under heavy load while climbing and accelerating for a top-level shifting experience.