Shimano RD-R8150 Ultegra Di2 12-Speed Rear Derailleur

Now simplified with a single derailleur cage length, the new 12-speed Shimano Ultegra R8150 rear derailleur packs our fastest, most precise shifting into a more approachable option. With our fastest, most accurate shifting, the new 12-speed Ultegra R8150 rear derailleur is more versatile than ever thanks to a single cage length option that is compatible with 28-34T low sprockets.Ultegra Shadow design with Di2 technology, shifting is easy and precise - just a light touch, as soft as a mouse click, is sufficient for the front or rear derailleur to instantaneously select the correct gearThe 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 devises and replaces the handlebar junctionButton on the derailleur for Di2 operations, and LED light denotes synchronized shift mode, setting mode and charge requirementsSleek appearance with low profile Shadow design construction reduces risk of damage in a crashProgrammed automatic motion at the touch of a switch makes this derailleur quick, smooth and effortless to shiftThe removal of traditional mechanical cables in favour of electrical wires not only eliminates poor shifting caused by contaminates, corrosion and stretching, but provides effortless gear shiftsDerailleur contains a saver (fuse) function, where the inner structure is protected from strong impactsHigh 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 shifting12-speed E-tube Di2 compatibleWide gear ratio compatible up to 11-34T