Shimano Dura-ace DI2 RD-R9250 Rear Derailleur

The RD-R9250 12-speed rear derailleur is the central element of Shimano's top-of-the-line Dura-Ace Di2 road bike groupset when it comes to semi-wireless as well as fully-wired shifting. It consists mainly of aluminium and carbon, and therefore has a weight savings of almost 50 grams compared to the Ultegra model. The RD-R9250 has even more to offer than a conventional rear derailleur, because in the disc brake version it communicates wirelessly with the shift/brake levers via the built-in wireless chip. In the rim brake version with a cable connection to the STIs, it is responsible for coupling the components. This is done via a function button, which is also used to adjust the rear derailleur. You can also use the button to check the battery level, change the shift mode from manual to Synchro and Semi-Synchro Shift, and establish a Bluetooth connection to a bike computer or smartphone. An LED display helps you to do this.

The rear derailleur is connected to the battery via a cable, from which a cable also runs to the front derailleur and possibly to the STIs. It has a charging port that allows you to easily recharge your circuit using the matching charging cable. In racing and training use, RD-R9250 convinces with an extremely high shifting speed that clearly surpasses that of its predecessor. Its flat Shadow design reduces the risk of snagging and optimises shifting. With a total capacity of 37 teeth, you can shift 12-speed cassettes with a largest sprocket of 28 to 34 teeth.


SPECIFICATIONS

Series: Dura-Ace Di2 R9250
Application: Road, Triathlon & Time Trial
Gearing: 12-speed
Mount: Standard (Direct Mount compatible)
Capacity: 37-tooth
Compatibility: Shimano Road 12-speed
Compatibility - Chains: HG 12-speed


TECHNICAL INFORMATION

Derailleur Pulleys: 11-tooth
Outer Cage Material: Carbon (CFRP)
Inner Cage Material: Carbon (CFRP)
Other Materials: Aluminium, carbon (CFRP)



COMPATIBILITY

Power Cable: EW-SD300-I (1 x connection)
Shift/Brake Lever: ST-R9250, ST-R9270, ST-R7170, ST-R9160, ST-R9180, ST-R8150, ST-R8170, ST-R8060
Cassette: CS-R9200-12, CS-R8100-12, CS-R8101-12, CS-R7100-12, CS-R7101-12
Chain: CN-M9100, CN-M8100, CN-M7100, CN-M6100
Charging Cable: EW-EC300



FEATURES

- Function button, charging port and wireless system in one compact unit
- Di2 wireless chip with low interference probability, high processing speed and low power consumption
- LED status display (battery, pairing, settings mode, Synchro Shift)
- Takes over the function of previous wireless units in establishing a wireless connection with compatible cycling computers
- Extremely high shifting speed: 58% faster than RD-R9150
- Flat design
- Connected to battery via cable
- Only one cage length for all gradations
- Firmware updates via E-Tube Project
- 4 fluorine-coated joint bushes
- Tension and guide roller bearing
- Painted cage plates