Following the trends in the bike industry, its not all that surprising that groupsets are taking to the gravel, and we appreciate the careful attention and time that Shimano took in designing the GRX RD-RX810 Rear Derailleur for powering through variable conditions on a drop-bar bike. If you've been following Shimano in the all-road and off-road scene, the derailleur won't look shocking to you. In fact, it's nearly identical to the RX version of the Ultegra derailleur that was launched just last year, which took queues from the Shadow mountain bike derailleur, adding in a clutch mechanism to reduce chain slap and dropped chains for a quieter and more secure ride both on and off-road. When in the on position, the clutch increases the spring force to provide crisp shifting and zero chain slap and is easily flipped off for wheel changes. What we find to be big news is that Shimano crafts the GRX RD-RX810 for both 1x and 2x setups, stepping outside of the 2x only comfort zone that the brand had held to, with this short-cage model being optimized for an 11 - 34t cassette. Following in the footsteps of the revamped Dura-Ace and Ultegra groups, this GRX derailleur gets its Shadow cage treatment placing it closer to the frame and under the cassette keeping it out of harm's way and less likely to take the brunt of a driveside crash. This also allows the derailleur to move in a much more linear path allowing for shorter throws with less effort. The RX810 model comes in one cage length, short, which accommodates an 11-34t cassette allowing for a wide range gear ratio when paired with a double without the usual huge jumps between the cogs like on a 1x setup. Sticking to what the brand's customers know well, Shimano continues to use the Dura-Ace, Ultegra, and Tiagra designation with the GRX line, with this particular model falling under the Ultegra umbrella, which means it gets the usual materials and finishes that we expect from a groupset that's just one step from the top...