Shimano Dura-Ace RD-R9250 Di2 12-Speed Derailleur Black

The Shimano Dura-Ace RD-R9250 Di2 12-Speed Derailleur uses Di2 (Digital Integrated Intelligence) technology. With programmed automatic motion at the touch of a switch, the Dura-Ace Di2 rear derailleur is quick, smooth and effortless, making for unmatched drivetrain efficiency.The rear derailleur is now the brains of the system with wireless connectivity to the shifters. It acts as the point the system is charged, provides ANT+ connection to 3rd party devices and replaces the handlebar junction.Shimano Dura-Ace RD-R9250 Di2 12-Speed Derailleur FeaturesButton on the derailleur for Di2 operations, and LED light denotes synchronized shift mode, setting mode and charge requirementsProgrammed automatic motion at the touch of a switch makes this derailleur quick, smooth and effortless to shiftSynchronized Shift designed, developed to choose the next biggest or lowest gear ratio irrespective of whether a gear change needs to be made by the front or rear derailleurThe removal of traditional mechanical cables in favour of electrical wires not only eliminates poor shifting caused by contaminates, corrosion and stretchingLow profile Shadow derailleur designDerailleur contains a saver (fuse) function, where the inner structure is protected from strong impacts11-34T wide gear ratio capacity will cater for compact setups as well as the traditional road doubleFull carbon fibre inner and outer pulley plates enhance rigidity and reduce weightTitanium B axle bolt for further weight savingsHigh tolerance cold forged aluminium link plates and body construction is extremely light and durableFour self-lubricating micro-machined fluorine-coated link pivot bushings provide low-friction shiftingPulleys are made of tough DuPont Zytel for longer life and less chain noise12-speed E-tube Di2 compatible