Getting a bike ready for hydraulic disc brakes and 12-speed shifting used to mean sourcing four separate parts and hoping the hose lengths worked out. The Shimano GRX ST-RX820 dual control lever with caliper set solves that by shipping the lever, flat mount caliper, and pre-bled hydraulic hose as a matched, ready-to-install unit. The front set uses a 1000mm SM-BH90 hose for the run from the left lever to the fork-mounted caliper, and the rear set uses a 1700mm hose to reach the chainstay caliper on most frame sizes.

The lever body itself is where GRX earns its gravel-specific label. Shimano reshaped the hood taller and with more pronounced texturing than the road-going 105 or Ultegra levers, giving you something substantial to hang onto when the surface turns loose or the bar starts to bounce. The brake blade carries an anti-slip coating that Shimano adapted from its fishing rod division, which sounds like marketing until you ride in the rain and notice your fingers actually stay planted. Reach and free-stroke adjustment are both built in, so you can dial the lever position to your hand size and set the engagement point where you want it.

Servo Wave hydraulic actuation shapes the lever feel through the stroke — quick pad contact at the top followed by progressive power as you pull deeper. That means the bite point is easy to find on rough descents where you're feathering the lever rather than grabbing a fistful. The BR-RX820 flat mount caliper runs 10 percent wider pad clearance than the previous generation, which reduces the rotor rub and squealing that plagued earlier GRX brakes when frames flexed under load or rotors picked up heat.... Read More