Shimano Dura-ace RD-R9250 Rear Derailleur DI2 12-SPEED

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

Material: Aluminium, carbon composite
Version: 12-speed
Compatibility: Shimano Dura Ace ST-R9250, ST-R9270 shift lever
Total capacity: 37 teeth (T)
Max.difference in front: 16T (difference between smallest and largest chainring)
Total capacity: 37T
Low Sprocket: Max.: 34T, Min.: 30T
Top Sprocket: Max 11T, Min 11T
Mount: Direct Mount

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