Servo Wave technology governs the brake lever action. The mechanism accelerates pad travel during the initial portion of the lever stroke, bringing the pads into contact with the rotor quickly with minimal hand movement. Once contact occurs, the leverage ratio changes to provide progressive power application through the remainder of the stroke. This two-stage action delivers responsive initial engagement followed by precise modulation for the actual braking phase. Reach adjust allows you to position the lever blade closer to or farther from the handlebar across a 16.4mm range, accommodating different hand sizes and grip preferences. Free stroke adjustment fine-tunes the point at which the pads make initial contact.

The BR-R8170 caliper uses a two-piece construction that reduces weight while improving rigidity compared to the previous generation. Shimano increased pad clearance by 10 percent, which reduces the likelihood of rotor rub and makes wheel changes less fussy. That extra clearance also keeps the brakes quieter when rotors develop slight warps from heat cycling. The caliper mounts via the Flat Mount standard and accepts 140mm or 160mm rotors depending on the adapter configuration. One Way Bleeding simplifies maintenance by streamlining the oil path through the system, preventing air bubbles from getting trapped in the caliper body during the bleed process. Shimano supplies a bleed funnel with the caliper, and the procedure requires only basic tools and their mineral oil.

The included L03A brake pads feature Shimano's finned Ice Technologies construction. Aluminum fins extend from the backing plate and act as a heat sink, pulling thermal energy away from the friction surface and dissipating it into the airflow. Resin compound provides consistent bite characteristics across temperature ranges and generates less noise than metallic alternatives during wet conditions. These pads work with all Ice Technologies compatible calipers in the Shimano road and gravel lineup.

The hydraulic hose kit uses SM-BH90-JK-SSR hose with straight fittings at both ends. Shimano fills the system with mineral oil before shipping, so you can install the caliper, bleed out any air that entered during transit, and ride. Mineral oil is less aggressive than DOT fluid, which means spills clean up easily and the system tolerates minor contamination without degrading seal materials. The caliper includes mounting hardware for various frame adapter thicknesses from 10mm to 35mm, covering the range of Flat Mount configurations found on current road and gravel frames. Left and right units ship with appropriate hose lengths for their respective positions, with the rear including extra length to accommodate the longer routing path.