The evolution of Shimano's Di2 drivetrain system rolls on. With the release of the R9100 series components, an entirely new hydraulic disc braking system was developed from the STI shift/brake levers all the way down to the rotors. The now legendary Di2 electronic shifting version is here, the ST9170 Di2 STI Levers for hydraulic disc brakes. In the process of developing Dura-Ace R9100, new ergonomic and efficiencies were built into the shifting systems for both mechanical and electronic versions, with options added via the E-Tube project for customizing the shifting set-up of the R9170 Di2 models. Sold as individual levers, left or right, with the specific BR-R9170 complete flat mount brake caliper assembly and SM-BH90 hydraulic hose kit; the buyer still needs to build the E-Tube Di2 wire connection kits required for their bike and desired set-up.

The new Di2 system offers substantial opportunities for direct customization via e-Tube. You can set your carbon shift levers up for Shimano's SyncroShift with two primary options. In fully synchronized shifting, the front derailleur automatically shifts off the placement and shifting of the rear derailleur in combination based on your choices. In semi-syncronization mode, the rider shifts both front and rear normally, but front shifts are augmented by an automated rear shift to moderate the large jumps and pedal lag that can cause. In normal shifting mode you can still program the shift buttons to your preference for which each shift action each lever actuates, or even control compatible computer head unit mode or screen buttons. The E-Tube system allows to do all this from their app on mobile devices or directly through a PC interface. With E-Tube, your system must all be set-up and physically connected, and for the new system you will need to be using a BM-DN100 (external battery mount) or BT-DN110 (built-in battery) and EW-WU101 ANT/BLE wireless connector.

From a physical perspective, the new 9170 hydraulic lever is almost the exact same physical size and shape as it's mechanical brother. Slimmer, with much better ergonomics than ever before, as well as lighter weight, these levers shift a more refined electronic drivetrain with a more positive button response. You still have the capability for integrating with for satellite (sprinter, climber) buttons as well. The new textured hood design provides excellent grip, some mild cushion, and covers the lightweight new plastic composite body housing. The strength and reliability of the housing is what allowed Shimano to engineer the shift action and hydraulic interface down to it's most compact size.... Read More