Shimano GRX Di2 Rear Derailleur RD-RX815

Shimano GRX Di2, the new gravel components in the electronic Di2 version, designed for 11x2-speed drivetrains and cassettes up to 34 teeth. With a 48/31-tooth crankset, the GRX 11x2-speed components offer a very wide gear range for a variety of applications, from gravel and cyclocross to touring. Shimano GRX, the first gravel-specific component family designed equally for fast progress and safe bike handling on loose surfaces, is the result of an intensive and extensive research, testing and development process that incorporated information and feedback from countless riders who are out and about on trails, forest tracks, gravel roads or tarmac. Whether it’s gravel riding in the strictest sense, road bike adventures off the beaten track, bikepacking, commuting or the demands of competitive cyclocross riders: Shimano’s GRX components offer countless options that leave nothing to be desired, from gear ratios and spacing, customisable ergonomics and integrated control of dropper seatposts right through to specific gravel wheelsets with wider rim profiles. The 11-speed road bike cassettes (11x30 to 11-34 teeth) can be used.

Shimano GRX RD-RX815 Di2 rear derailleur

The RX 815 version of the GRX Di2 rear derailleur allows the use of cassettes with up to 34 teeth. The new GRX Di2 rear derailleurs deliver quiet, smooth, precise and reliable shifting even on the most demanding terrain. This is primarily thanks to the Shadow RD+ chain stabilisation system, which prevents chain slap and unnecessary movement of the derailleur cage, thereby ensuring uninterrupted shifting performance. Similar to Shimano’s mountain bike rear derailleurs, there is an on/off switch next to the upper pulley. When activated, the derailleur pawl locks into place to reduce excessive movement, noise and general chain noise. The GRX Di2 rear derailleur features the Syncro Shift function, programmable via the Bluetooth interface (EW-WU111), allowing the rear derailleur and front derailleur to be operated with a single lever. The system then automatically selects the front derailleur function to shift into the next gear. Precise, lightning-fast gear changes at the touch of a button, in any situation. Precise. Equipped with a crash mechanism that disconnects the connection to the motor in the event of strong external forces to prevent damage.

Synchro-Shift technology

Synchro-Shift technology simplifies shifting immensely 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 Shadow RD-RX815

With its sophisticated technology, the Shimano Shadow rear derailleur is particularly well-suited to a more aggressive riding style. Its extremely slim profile brings a number of advancements. Thanks to its flat design and construction based on single preload, the rear derailleur does not strike the chainstay even under the harshest conditions. The shifting operates smoothly and quietly.

Shimano Di2 installation:

Installing Shimano Di2 components is almost easier than fitting traditional gear systems. The standardised cable connectors and junction box ensure straightforward and quick installation. The shift levers are connected to Junction Port A on the junction box; a cable runs from Junction Port A to Junction Port B on the junction box, and from there the cables run to the rear derailleur, front derailleur and battery. The battery can be mounted externally on the bottle cage or internally in the seat tube or down tube. Frames specifically designed for this purpose are required for internal cable routing.

To use the wireless function, the new BT-DN110 battery and the EW-WU111 Bluetooth module are also required.

Shimano RD-RX815 GS Rear Derailleur Technical Specifications:

• Wide Link Design: the wider outer parallelogram increases stiffness
• Cold-forged aluminium
• 11-speed compatible
• Bearing-mounted, low-friction
• Largest sprocket to be shifted: 34 teeth at the rear
• Total capacity: 39 teeth
• Compatible only with GRX, Ultegra and Dura-Ace Di2 shifters (11x2-speed)

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