Rear

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience along 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-RX815 Di2 version offers the digital precision of Shimano electronic shifting with synchronization and 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 - Total capacity: 38T - Smooth and reliable mixed surface shifting - Compatible with current road Dual Control Lever - Maximum front difference: 17T - High cog: Max. 11T/Min. 11T - Low cog: Max. 34T/Min. 30T

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-RX817 Di2 version offers the digital precision of Shimano electronic shifting, as well as synchronized shifting and 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 - Compatible with current road Dual Control Levers - High cog: Max. 11T/Min. 11T - Low cog: Max. 42T/Min. 40T - Total capacity: 31T