Shimano Dura Ace Di2 RD-R9250 rear derailleur

The 12-speed rear derailleur from the Dura Ace 9200 Di2 series, designed for cassettes ranging from 11-28 to 11-34 teeth

The components of the pros: the high-end Dura Ace wireless 12-speed series, crafted from the finest materials – titanium, carbon and aluminium.

Precise, lightning-fast shifting at the touch of a button, in any situation. The Shimano Dura Ace Di2 RD R9250 rear derailleur is even more compact and lighter than its predecessor and features E-Tube connectors for incredibly easy installation. Equipped with a crash mechanism that disconnects the connection to the motor in the event of strong external forces to prevent damage.

The new Di2 platform for the Dura-Ace 12-speed components requires no cable connection between the shift levers and the rear derailleur and front derailleurs. The Di2 Dual Control shift levers ST R9270 have the necessary wireless module integrated. Power is supplied by CR1632 batteries, which have a service life of up to 2 years. The Di2 12-speed rear derailleur, with its additional wireless unit, acts as a receiver and distributor of shift signals and is connected to the battery and front derailleur for power supply and shift command transmission. Additional wireless components, including those from third-party manufacturers, can also be paired with the rear derailleur. The shifting logic and speed of the shifting operations, semi-automatic or fully automatic shifting, etc., can be personalised using the E-Tube app.

Shimano Dura-Ace RD R9250 Di2 Rear Derailleur

The new Dura-Ace Di2 rear derailleur is the heart of the new Di2 12-speed groupset. It provides the wireless functionality and connection to external components, and also houses the charging port, replacing the previous SM-BCR2 charger. In addition, the rear derailleur houses the transmitter for wireless communication with the STI shifters and other external devices, including those from third-party manufacturers. Furthermore, it features the status LED and the adjustment button, which is used, for example, to switch between Synchro-Shift modes, meaning that the previous Junction A port, SM-RS910, is no longer required.

Synchro-Shift technology

Synchro-Shift technology greatly simplifies shifting and significantly reduces the number of decision-making processes that take place whilst riding. Particularly in crucial race situations or when riding at full throttle, riders often have to navigate a multitude of decision-making processes alongside the physical strain, which are frequently disrupted and lead to wrong decisions. The fewer decisions there are to make, the better the decisions will be and the more attention can be focused on the race. This is precisely what Shimano Synchro-Shift technology enables, always selecting the optimal next-higher or next-lower gear combination, regardless of whether this requires shifting at the rear derailleur and/or the front derailleur.

Shimano Synchro-Shift functions

• Full Synchro-Shift: The front derailleur reacts to the gear changes the rider makes on the rear derailleur. Essentially, this means that only one shifter with two buttons is needed to operate both the rear and front derailleurs.
• Semi Synchro-Shift: The rear derailleur responds to the gear changes the rider makes on the front derailleur. The rear derailleur automatically performs the necessary compensatory shifts for small changes in cadence when shifting up or down on the front derailleur.

Shimano 12-speed Di2 installation:

Shift commands are transmitted wirelessly from the shift levers to the rear derailleur. Only the rear derailleur and front derailleur are wired to the battery. This ensures a clean look and significantly reduces the installation effort. The shift levers are powered by CR1632 batteries. The shift levers feature an additional cable connection, allowing for the connection of auxiliary switches. Traditional cabling from the shift levers to the battery is also possible. The new battery has three slots.

Shimano Dura Ace DI2 RD R9250 Rear Derailleur Technical Specifications:

• Wide Link Design: the wider outer parallelogram increases stiffness
• Cold-forged aluminium
• CFRP rear derailleur cage
• Titanium hardware
• 12-speed compatible
• Bearing-mounted friction arms
• Smallest sprocket to be shifted, rear 11 teeth, maximum 14 teeth
• Largest sprocket to be shifted, rear 34 teeth, minimum 28 teeth
• Total capacity: 37 teeth
• Compatible only with Shimano Dura-Ace and Ultegra Di2 12x2-speed shifters
• Weight 215 grams (manufacturer’s specification)

Spare parts for the Dura Ace Di2 Rd R9250 rear derailleur:

• Y3GK98020, bracket axle unit
• Y3GK41000, B-axle 2
• Y3GK51000, Stax cable
• Y5ZR98040, End adjusting screw and plate
• Y3GK98030, Stroke adjusting screws and plate
• Y3GK89400, Charger cover
• Y3GK89000, Boot
• Y3GK44000, P-tension spring
• Y5PU130T0, P-seal ring
• Y3GK98040, Outer plate and fixing screw
• Y3GK98010, Pulley set
• Y3GK98050, Inner plate
• Y3GK98060, Pulley screw, 2 pcs
• Y3GK89600, GG adjustment gauge
• Y7HE40000, TL-EW300 plug tool
• IEWEC300A, EW-EC300 charging cable

Herstellerinformation: SHIMANO INC., 3-77 Oimatsu-cho, Sakai-ku, Sakai-shi, Osaka 590-8577, Japan, www.shimano.com | EU contact: Shimano Europe BV, High Tech Campus 92, 5656 AG Eindhoven, The Netherlands, www.shimano.com