Rear

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience while delivering shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features an ON/OFF switch for the chain stabilizer. The RD-RX810 rear derailleur is compatible with road cassettes with a max cog size of 34T. - Adjustable, gravel-tuned chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Silent and uninterrupted rear shifting on rough terrain - Low cog: Max. 34T/Min. 30T - High cog: Max. 11T/Min. 11T - Total capacity: 40T - Compatible with current road Dual Control Lever - Maximum front chainring range: 17T

Ultegra RX brings Shimano's pioneering chain stabilizing technology to road cycling, delivering smooth and precise shifting over technical terrain. It expands road bike capabilities, inspiring confidence on any surface and drives the evolution of road cycling to include greater elements of adventure. No longer is the road bike narrowly defined. Shimano Ultegra RX broadens the notion of drop bar riding and emboldens cyclist to explore further. - Chain Stabilizer mechanism adopted from MTB design - Stabilizer ON/OFF switch - Compatible with current road dual control lever - Shadow RD technology - Direct mount compatible - Maximum cog size: 34t - Total capacity: 39t

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience with shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features and ON/OFF switch for the chain stabilizer. The RD-RX812 rear derailleur is compatible with MTB cassettes with a max cog size of 42T. - Adjustable, gravel-tuned chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Silent and uninterrupted rear shifting on rough terrain - Smooth and reliable mixed-surface shifting - Compatible with current road Dual Control Levers - High cog: Max. 11T/Min. 11T - Low cog: Max. 42T/Min. 40T - Total capacity: 31T

Shimano's electric-shifting 11-speed Ultegra Di2 Rear Derailleur is driven by battery power and a servo motor, so shifts are fast, precise, and perfect every time. It's made of light, tough cold-forged aluminum while mid-cage and short-cage models give you your choice of cassette. Since there aren't any cables or housing to stretch or fail, maintenance is dramatically reduced and shifting accuracy is unprecedented. This high-tech derailleur is even designed to move inward under impact to reduce the potential for damage in a crash.