The GRX gravel group options include a first for Shimano road-style components, a 1x drivetrain option. As such, it was necessary to develop a left side brake lever without a shift mechanism, another first since STI Dual Control arrived with 8-speed. The GRX BL-RX810 Brake Lever with Caliper Set is just that, a left side front brake lever, shaped just as the GRX mechanical shift/brake lever is, with a fully set-up pre-bled, Flat Mount BR-RX810 hydraulic disc brake caliper. As simple as this sounds, Shimano has been late to the 1x drivetrain party and even though aftermarket parts would allow for their 11-speed road drivetrains to run as 1x set-ups, the rider still had to use a Dual Control lever for the brake on the left side. This GRX BL-RX810 Brake Lever with Caliper is warmly welcomed, despite the fact it is shaped and intended only for GRX 1x use.

Shimano developed GRX for the rough terrain and mixed surfaces that make gravel riding so challenging, fatiguing and fun. The ergonomics make for easier leverage, hand positions, comfort and tactile use despite the constant vibration and small impacts of gravel riding. The lever blade feels correct and proper with a standard road drop bar shape, as well as the flared drop bars popular for gravel.

The set consists of the left-side BL-RX810 Brake Lever with the Flat Mount BR-RX810-F hydraulic disc brake caliper with IceTech finned disc pads, and all necessary hardware. The system is pre-bled and connected with the SM-BH90-JK-SSR hydraulic hose system from lever to caliper. Shimano's Mineral Oil hydraulic system makes it fairly simple to set the proper housing length and bleed for best braking contact.