Shimano Ultegra Di2 RD-R8150 12 Speed Rear Derailleur (A)

The Di2 actuators in the front and rear derailleurs of the current Ultegra series enable a significantly higher movement speed for a shorter movement time when changing gears and correspondingly rapid shifting processes.

The Shimano Ultegra Di2 RD-R8150 rear derailleur speeds up the shifting process by 58 % compared to the previous generation Dura Ace model RD-R9150. The rear derailleur with an uniform cage length and an increased gear ratio of 34 teeth is thus not only faster than ever before, but also guarantees highly precise functionality under all conditions.

The built-in transmitter ensures wireless communication with the STI brake/shift levers ensuring podium-worthy, lightning-fast and precise shifting. Using Bluetooth and ANT+, it is also responsible for data transmission to the E-Tube Project and E-Tube Ride apps as well as to third-party devices.

Besides the charging port, the Top Normal rear derailleur features a button for certain Di2 settings and an LED for status display informing you about battery level, pairing and setting mode, for example.

Technologies

Shadow RD – With their sophisticated technology, Shimano Shadow RD rear derailleurs are especially intended for more aggressive riding style. Their super low profile design carries many benefits. Thanks to the low profile and a single tension construction, the derailleur does not hit the chain stay in rough riding conditions. The result is smooth and silent performance.

Specifications