Shimano GRX RX825 Di2 Disc Brake Shifter

The Shimano GRX RX825 Di2 Disc Brake Shifter combines a hydraulic disc brake lever and a 12-speed electronic shifter in one unit, designed for gravel bikes with flared drop bars. Shifting is Di2, so a button press sends a signal to the derailleur rather than pulling a cable, and the action stays the same whether you are on pavement or bouncing down a rough fire road.

The hood is built for the way gravel riders spend their time, which is mostly on the hoods in loose terrain. Shimano shapes it with a raised, rounded profile and a ribbed texture, and the lever blade carries an anti-slip coating, so your hands stay planted when the trail gets rough or wet. The shape is also designed for the angle of a flared bar, where your wrists sit differently than on a traditional road bar.

Braking uses Shimano's Servo Wave action, which brings the pads toward the rotor quickly early in the stroke and then shifts to a firmer, more controlled feel. In practice that means the lever engages promptly without feeling abrupt as you load it up on a long descent. Reach and free-stroke adjustment let you set the lever position and bite point to your hand size and preference.

Shift buttons can be customized through Shimano's E-TUBE PROJECT app, and the Front Shift Next feature lets you assign a button to shift the front derailleur on a 2x setup. Each lever runs on coin-cell batteries, which Shimano estimates will last several years of typical riding. Sold per side, the RX825 pairs with a compatible GRX Di2 rear derailleur and hydraulic caliper, so confirm your drivetrain before ordering.