The Shimano XTR BR-M9120 rear disc brake set delivers flagship-grade stopping power for trail and enduro riding. Pairing the BL-M9120 lever with the BR-M9120 4-piston caliper, this J-Kit arrives pre-bled and ready to install — giving you immediate, confident control on the descents that matter most.

Highlights

• XTR M9100-series 4-piston hydraulic disc brake — Shimano's most advanced trail braking system
• 10% more braking force compared to the previous generation
• Lever body 8% stiffer than its predecessor for improved power transfer
• Servo Wave technology for progressive, controlled brake feel
• N03A resin pads with radiator fin — quieter modulation and extended pad life through active cooling
• I-Spec EV lever mount for direct integration of XTR shifters
• J-Kit hose joint with integrated olive for straightforward hose installation
• Includes 1700mm pre-bled SM-BH90-SBM hydraulic hose

4-Piston Mono-Body Caliper

The BR-M9120 caliper is machined from a single cold-forged aluminium block using Shimano's Mono-Body construction. Four ceramic pistons deliver even clamping force across the rotor, resulting in powerful, consistent braking with reduced hand fatigue on long descents. Post-mount fitment suits most modern trail and enduro frames.

Lever Design & Ergonomics

The BL-M9120 left lever features tool-free reach adjustment and a free-travel adjustment, allowing you to dial in the exact feel for your riding style. The I-Spec EV clamp is compatible with XTR M9100 shifters, enabling a clean cockpit setup. Servo Wave actuation provides a short initial lever stroke followed by progressive power increase — ideal for technical trail riding where modulation is critical.

Resin Pads with Radiator Fin

The included N03A resin compound pads are paired with a radiator fin that actively dissipates heat during sustained braking. Resin pads provide less noise, excellent modulation, and are well-suited to Australian conditions across a wide range of trail surfaces. The fin design helps extend pad life by reducing heat fade on long alpine descents.

Compatibility & Fit

• Caliper mount: Post mount (IS mount adapter available separately)
• Compatible rotors: Shimano RT-MT900 and other M9100-series rotors, 140–203mm (sold separately)
• Hydraulic fluid: Shimano Mineral Oil
• Hose standard: SM-BH90-SBM (1700mm hose included)
• Pad compatibility: N03A resin (included) or N04C metal with radiator fin (sold separately)
• Lever clamp: I-Spec EV — compatible with XTR M9100 shifters
• This set includes the left lever (rear brake in Australian setup)