Shimano Dura-Ace R9100 11sp Rear DeraillleurAdopting race-proven technologies from Shimano's MTB range, the Dura-Ace R9100 Road Rear Derailleur now brings the "Shadow" technology to road cyclists. The shadow design places this road bike rear derailleur under the chainstay and cassette to give a slimmer profile, which not only improves aerodynamics but helps prevent damage in a crash.This revised Shadow design brings you precise and faster gear shifts than on previous models plus even faster wheel changes for race days. This is thanks to the Shadow feature moving the derailleur out of the way of the rear dropouts.The Dura-Ace R9100 Road Rear Derailleur derailleur only comes in one length and will work with cassette sprockets up to 30T. This means that this rear mech offers a greater rider tuned ratio than previous editions. Features: Maximum Sprocket: 30T Minimum Sprocket: 11T Maximum Front Difference: 16T Total Capacity: 35T Stable shifting performance Distance between pulleys is maintained through the shifting range Shimano Shadow RD construction Low profile rear derailleur design Race endurance for less damage in crash Adapted for race specific frame design Mount Type: Standard mount Manufacturer's Part Number: RDR9100SS Weight: 158gA 2 year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.