Shimano 105 Di2 Rear Derailleur RD-R7150

The new 105 rear derailleur is the centrepiece of the new Di2 components. It provides the wireless function and connection to external components, and also includes the charging port, replacing the previous SM-BCR2 charger. The rear derailleur also 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 knob, which is used, for example, to switch between Synchro-Shift modes, meaning that the previous Junction A port is no longer required.

The new Shimano 105 relies on a hybrid system comprising a wireless connection between the cockpit components and a cable connection between the rear derailleur, front derailleur and the central battery – usually housed in the seat tube – ensuring maximum reliability in all conditions. And just like its big brothers DURA-ACE and ULTEGRA, the SHIMANO 105 also excels with extensive options for quickly and easily customising it to the rider’s wishes and preferences via the E-TUBE app.

Via E-TUBE PROJECT, the gear system can be individually configured by, for example, adjusting the shift speed, the number of shifts when the button is held down, or the Synchro-Shift and Semi-Synchro-Shift functionality.

Furthermore, the system can be paired with many third-party cycle computers, including Garmin and Wahoo. This allows these devices to display, for example, the current gear or the battery charge level.

The new Di2 platform for 12-speed components requires no cable connection to the rear derailleur and front derailleurs. The Di2 Dual Control shift levers ST-R7170 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.

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 connected to the battery via cables. 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, which allows for the connection of auxiliary switches.

Shimano 105 DI2 RD R7150 Rear Derailleur Technical Specifications:

• Wide Link Design: the wider outer parallelogram increases stiffness
• Cold-forged aluminium
• 12-speed compatible
• Bearing-mounted friction arms
• Smallest sprocket to be shifted, rear 11 teeth, maximum 14 teeth
• Largest sprocket to be shifted, rear 36 teeth, minimum 32 teeth
• Total capacity: 39 teeth
• Compatible only with Shimano Dura-Ace and Ultegra Di2 12x2-speed shifters
• Weight 302 grams (manufacturer’s specification)

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