Hope

RX4+ SL Flat Mount SRAM Disc Brake

Hope RX4+ SL Flat Mount SRAM Disc Brake Caliper is a slim 4-piston, DOT-fluid caliper built for riders who want more control and consistency from SRAM road and gravel hydraulic systems. The precision CNC-machined monobloc body boosts rigidity for a cleaner lever feel, while the updated narrower bore cap reduces overall caliper width for improved frame and fork clearance—especially valuable on tight flat-mount builds. 

Upgrade-focused details that matter on the road and gravel

1. Rigid CNC monobloc construction - A stiffer caliper body helps reduce vague lever feel and can minimize pad knock and rub issues from flex under load
2. Narrower bore cap design - Reduced caliper width improves compatibility with a wider range of frames and forks where clearance is limited
3. Slimline 4-piston power - Adds controlled braking force and modulation for high-speed descending, heavy riders, and loaded gravel setups
4. DOT fluid / SRAM lever compatibility - Designed for DOT-based hydraulic systems, making it a purpose-built performance match for SRAM road and gravel levers
5. RX2-style bleed nipple - Updated bleed interface supports simpler, cleaner bleeding and more consistent maintenance results
6. Top-entry pad access + fully serviceable design - Fast pad changes without fighting the caliper, with rebuildability that supports long service life

• Material - CNC-machined 2014-T6 aluminum for high strength with weight-conscious design
• Rotor sizing - Compatible with common 140 / 160 / 180mm rotor sizes when paired with the correct mounts/adapters