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Brembo GP4-RB High Performance Front Brake Caliper

P4 30/34mm | Billet 2-Piece | 108mm Radial Mount | Hard Anodized Black

Left Side Caliper | Part Number: 120B47340

The Brembo GP4-RB 120B47340 is a premium racing-derived left-side radial brake caliper engineered for riders demanding exceptional braking performance, race-level modulation, and aggressive factory superbike styling. Precision-machined from billet aluminum and finished in hard anodized black with Brembo’s iconic red logo, the GP4-RB combines lightweight construction, superior rigidity, and MotoGP-inspired braking technology for serious street and track applications.

Developed as part of Brembo’s prestigious Upgrade Line, the GP4-RB is designed for motorcycles utilizing 108mm radial mount spacing and delivers the braking precision and hydraulic consistency expected from Brembo’s top-tier billet racing calipers.

Item Summary

• Genuine Brembo GP4-RB front brake caliper
• Brembo Part Number: 120B47340
• LEFT side caliper
• CNC billet aluminum 2-piece construction
• 108mm radial mount spacing
• 30mm / 34mm differentiated aluminum pistons
• Hard anodized black finish
• Glossy red Brembo logo
• Brembo Upgrade Line product
• Pads included
• Compatible with 32–34mm disc height
• High-rigidity racing design
• Designed for aggressive street and track riding
• Manufactured in Italy

Billet Racing Construction

The Brembo GP4-RB is carved from billet aluminum using advanced CNC machining technology to maximize structural rigidity and braking precision. Unlike conventional cast calipers, the billet 2-piece body provides significantly improved stiffness, allowing for more consistent hydraulic pressure and sharper braking feel during aggressive riding conditions.

The rigid billet construction improves:

• Lever feel
• Braking consistency
• Rider confidence
• Modulation precision
• Resistance to flex under heavy braking

This race-oriented architecture makes the GP4-RB ideal for riders seeking a true factory racing braking experience.

Advanced 30/34mm Piston Configuration

The GP4-RB utilizes Brembo’s differentiated piston layout featuring:

• 2 × 30mm pistons
• 2 × 34mm pistons

This staggered piston design improves pressure distribution across the brake pads while enhancing braking controllability and modulation. The aluminum pistons also reduce weight and improve thermal stability during repeated high-load braking cycles.

Performance Benefits

• Strong braking power
• Improved modulation
• More progressive lever feel
• Better rider feedback
• Consistent braking performance

Hard Anodized Racing Finish

The GP4-RB features a premium hard anodized black surface treatment that enhances durability and corrosion resistance while maintaining an aggressive factory racing appearance. Brembo’s embossed red logo completes the caliper’s unmistakable motorsport styling.

Finish Benefits

• Enhanced corrosion resistance
• Increased surface durability
• Long-lasting racing appearance
• Premium superbike aesthetics

Technical Specifications

Included In The Box

• Brembo GP4-RB left caliper
• Brembo sintered brake pads
• Anti-vibration spring hardware
• Brembo installation instructions
• Brembo racing thermotape temperature strips
• Brembo decals/stickers

Key Features

CNC Billet Aluminum Construction

Precision-machined billet body provides exceptional rigidity and premium braking feel.

Differentiated Piston Design

30/34mm piston layout improves pressure distribution and modulation characteristics.

Racing-Derived Brembo Technology

Developed using Brembo’s extensive experience in MotoGP and World Superbike competition.

Lightweight High-Performance Design

Reduced weight improves front-end feel and braking response during aggressive riding.

Premium Racing Appearance

Hard anodized black finish with Brembo red logo creates authentic factory superbike styling.

Compatible Brake Pads & Spare Parts

Genuine Brembo Compatible Pads

Replacement Components

Matching Caliper

The complete left/right kit is sold under Brembo part number 220B47340.

Recommended Supporting Components

Recommended Brembo Master Cylinders

For optimal braking performance, the GP4-RB is commonly paired with:

• Brembo 17RCS radial master cylinder
• Brembo RCS Corsa Corta master cylinder

These master cylinders maximize braking modulation, hydraulic leverage, and rider feedback.

Recommended Brake Rotors

Compatible with:

• OEM brake discs
• Brembo T-Drive rotors
• Brembo HPK racing rotors

Designed for approximately 5.5mm rotor thickness and 32–34mm disc height.

Important Fitment Notes

• Designed for motorcycles utilizing 108mm radial mount spacing
• LEFT side caliper only
• Compatible with 32–34mm disc height
• Some motorcycles require spacers and longer mounting bolts
• Professional installation strongly recommended
• Brake system must be properly bled after installation
• ABS compatibility varies by motorcycle application

Why Choose the Brembo GP4-RB 120B47340?

The Brembo GP4-RB combines race-derived billet construction, advanced differentiated piston technology, and premium Brembo styling into one of the finest radial brake calipers available for modern sportbikes. Designed to maximize braking precision, rigidity, and rider control, the GP4-RB delivers exceptional performance for riders demanding a true racing feel on both the street and track.

Key Advantages

• CNC billet aluminum construction
• Exceptional braking rigidity
• Outstanding lever feel and modulation
• Race-derived Brembo technology
• Lightweight high-performance design
• Premium hard anodized finish
• Compatible with Brembo racing pad compounds
• Genuine Italian Brembo engineering

For riders building a premium superbike braking system or upgrading their motorcycle with authentic racing technology, the Brembo GP4-RB 120B47340 delivers elite-level braking performance with unmistakable Brembo pedigree.