Shimano Dura-Ace Di2 ST-R9170 Shifter/Hydraulic Brake Lever

Shimano Dura-Ace Di2 ST-R9170 Shifter/Hydraulic Brake Lever Info

The hydraulic brake version of Dura-Ace Di2 is this: the ST-R9170 Shift/Hydraulic Brake Lever Set. The levers are sold individually and come with hoses and fluid.

One of the great things about the 9170 iteration of the Di2 Hydraulic brake lever is the fact that Shimano has been able to streamline the hood body. It is about the same size, whether it is using cables or hoses to affect bike stopping. It’s a plus for your hands as well as for weight shaving. Weight for the set is down to 360g.

In terms of lever shape and action, the 9170 is indistinguishable from the 9150, the mechanical-braking set. The brake lever blade itself is slim and ergonomic. It’s easy to wrap your index finger around the lever when you’re both on the hoods and drops, and the reach can be adjusted to be the perfect distance from your drops.

While the profile of the hood and lever haven’t changed in terms of basic dimensions, they’ll feel better in your hands. This is for two reasons. First, is the textured rubber on the hood. Sticks to your hands and gloves better. Second, the shift buttons have been improved. The buttons have a more tactile “click” sensation so that you can be certain you’re shifting. The second, or rearward button is larger, and thus easier to find. In both cases, these improvements should appeal to those who spend time in bulky full-fingered gloves, as well as anyone else who likes more certainty in their shifting.

This ST-R9170 shifter is the front man for Shimano’s new initiative of programmable shifting. The brain is actually in the new battery, which will allow a few different modes. Normal shifting, semi-synchro, and full synchro. With full synchro, you’ll just go for easier or harder and the brain will do the rest. With semi-synchro, there will be multiple modes that you can program in, and then switch to them via a button on the exposed junction box. You’ll need an app or a Windows computer program and uplink to affect these changes, but they can be done.

One of the nice things about the 9170 iteration is that the components are backwards-compatible with E-Tube connected Di2 components, whether they’re Dura-Ace or Ultegra. This way, you can upgrade one component or all, depending on need.

The Shimano Dura-Ace Di2 ST-R9170 Shift/Brake Lever Set comes with hoses and fluid. You’ll need to purchase the electronic shift wiring separately.