Brembo Racing GP4-RR Monoblock Brake Caliper Kit 108mm XB9L2A1

For riders who demand absolute stopping authority on track, the Brembo GP4-RR Monoblock Brake Caliper Kit represents the pinnacle of racing brake technology. Engineered exclusively for circuit use, this 108mm kit combines a one-piece aluminium body with four titanium pistons and purpose-built thermal management — delivering the progressive, fade-resistant braking feel that separates podium finishes from also-rans. Important: this caliper kit carries no road-use homologation and is intended solely for racing and trackday applications.

Key Features

• Monoblock aluminium construction — the one-piece body eliminates flex between bolt faces, providing a direct, consistent lever feel under repeated hard braking
• Four titanium pistons (2x Ø32 mm, 2x Ø36 mm) — titanium's low thermal conductivity shields the brake fluid from heat soak, preserving pedal firmness deep into a braking zone
• Hard-anodised caliper body — the hard-coat finish resists abrasion, corrosion and heat discolouration through the most demanding track sessions
• Advanced cooling geometry — the caliper profile is designed to channel airflow and dissipate heat rapidly, reducing the risk of fluid vaporisation under racing conditions
• Compatible with DOT 4 and DOT 5.1 brake fluid — gives the technician flexibility to select the fluid that best suits ambient and track temperatures
• 30 mm offset and 7.25 mm maximum disc thickness — precise dimensional specification ensures correct disc clearance with matched Brembo racing discs

Purpose-Built Racing Performance

The GP4-RR sits at the top of Brembo's monoblock racing caliper range, developed directly from MotoGP and World Superbike programmes. Where multi-piece calipers rely on bolted halves, the monoblock design machines the entire body from a single billet of aluminium, removing any possibility of inter-body movement under peak clamping loads. The result is a brake that communicates crisply through the lever, allowing the rider to modulate braking pressure with surgical precision — lap after lap, session after session.

Thermal Control on Track

Heat is the enemy of braking performance. The GP4-RR addresses this through a combination of titanium pistons, which insulate the fluid from caliper body temperature, and a cooling-optimised body profile. Together these features allow consistent braking behaviour even at circuits with extended, high-speed braking zones. The hard-anodised surface treatment further protects the aluminium body against the thermal cycling that can degrade lesser calipers over a full race season.

Fitment and Compatibility

The Brembo GP4-RR Monoblock Brake Caliper Kit XB9L2A1 is designed for forks with a 108 mm axle-to-caliper mounting hole pitch. This specification is common to a wide range of supersport and superbike platforms, including but not limited to:

• Honda CBR 600 RR, CBR 1000 RR, CBR 1000 RR-R
• Kawasaki ZX-6R, ZX-10 R, ZX-10 RR
• Yamaha R6, R1, R1M
• Suzuki GSX-R 600, GSX-R 750, GSX-R 1000
• Ducati 848, 899, 959, 1199, 1199 S, 1199 R, 1299, 1299 S
• Aprilia RSV4, RSV4 R, RSV4 RR, RSV4 RF, RSV4 1100, RSV4 1100 Factory, RS 660, RS 457
• BMW S1000RR, HP4, HP4R, M1000RR
• Triumph Daytona 675, Daytona 675 R, Daytona 765, Street Triple 765 R, Street Triple 765 RS
• MV Agusta F3, F4
• KTM RC 390, RC8 1190

Always verify the fork mounting pitch and disc thickness on your specific machine before fitting. For use on track only — not approved for road use.

Compatible Spare Parts

• Bleed screw: part number 05281233
• Brembo bleed screw protection cap: part number 05150220

Specifications