The Ultegra R8150 12 speed Di2 technology delivers 58% faster rear shifting than RD-9150. Shimano’s wireless Di2 processing technology, increases transmission speed and performance, offering reliable, fast shifts every single time. Now the rear derailleur integrates the system charging port and a wireless connectivity unit together and simplified with a single derailleur cage length, the new 12-speed Shimano Ultegra R8150 rear derailleur packs Shimano's fastest, most precise shifting into a more approachable option that is compatible with cassettes from 11-28T to 11-34T.

- Model: RD-R8150

- Series: Ultegra R8100

- Rear speed: 12

- Average weight: 262g

- Remarks: w/o Bracket spec available

- Firmware update by E-Tube project:

- Total capacity: 39T

- Charging port (pcs): 1

- B-axle (Hollow axle):

- B-axle 2 (Hollow axle):

- Direct attachment (Conventional):

- Direct Mount:

- Fluoric coated link bushings: 4

- Low sprocket (Max): 34T

- Low sprocket (Min): 30T

- Top sprocket (Max): 14T

- Top sprocket (Min): 11T

- Front difference (Max): 16T

- Guide pulley bearing:

- Pulley Teeth: 11

- Top-normal spring type (Shimano Shadow RD):

- Charging cable: EW-EC300

- LED for system status: (battery, pairing, adjust mode, synchro shift)

- SD300 port (pcs): 1