Sold individually, as left or right, these 105 ST-R7170 Di2 Dual Control Levers are sold without the hydraulic disc brake caliper and hose kit. With R7100-series 12-speed, Shimano has dropped cable-actuated shifting so the only option is the new Di2-equipped R7170 lever system for disc brakes. There have been many changes to the Di2 system for this 12-speed group and the dual control levers carry differences from the 11-speed models. All-new lever ergonomics on the dual control levers bring new levels of rider comfort and control to road cycling. With fast wireless shifting and overall brake system improvements, these levers deliver the excellence of Di2 shifting and proper bike control in all conditions with disc braking.

Yes, the R7100-series features wireless shifting from the shift levers to the derailleurs via a battery system. The R7170 shifters carry dual coin cell batteries which power a dedicated, secure low power signal to the smart seatpost-based battery. No wires are required or used with the R7170 Dual Control Levers. The front and rear derailleurs are each directly wired to the 12-Speed compatible, 3-wiring port equipped, BT-DN300 battery with SD300 Di2 wires, which are thinner, lighter and more capable overall than the SD50 generation. There is no junction/control box required at or near the levers, as that system has been moved directly into the body of the rear derailleur. Not only is the system faster, lighter and more efficient, it also eliminates complicated and challenging fully wired set-ups through today's fully integrated internal wiring that runs through bar to stem and onto fork then into frame.

Don't sleep on the ergonomic improvements. The lever bodies have a flat section that is longer for better support of the hand and body weight, but also have a taller peak, again for better grip and control. These two aspects were driven by cyclist feedback, from pros to everyday enthusiasts. The same can be said for the larger and more defined shift buttons. The new hood design has excellent cushion and grip texture, complementing the overall feel and shape of the lever bodies. Di2 set-up, shift functions, battery level, and troubleshooting can all be done through the current generation e-Tube Project app via BLE communication available for iOS and Android smartphones, as well as the PC version.

The brake levers themselves still feature manual Reach Adjust so people with shorter fingers or smaller hands can more reasonably control the brake lever pull while hands are in the drops or sitting on the lever tops. Overall the action is lighter and smoother, but moderates the power with the aforementioned modulation for a defined, effective braking action throughout the lever stroke. The overall braking experience is enhanced at the R7170 disc caliper as well as the new Ice Technologies disc rotor design- bot sold separately.