RCB E2 SERIES BRAKING SYSTEM
RCB S1 SERIES BRAKING SYSTEM
RCB R1 4-Piston Forged Monoblock Axial Caliper (Left Side) is a professional-grade braking masterpiece engineered specifically to anchor high-performance double caliper (dual-disc) front brake setups.
By offering a dedicated mirror-image left side configuration, RCB allows riders to build a symmetrical twin-caliper front system. This configuration doubles total sweeping surface area, splits thermal loading across two rotors, and provides massive, track-ready stopping power for high-speed sportbikes, supermoto conversions, and custom maxi-scooters.
Key Features
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Monoblock Forged Architecture: Machined from a single, continuous piece of high-tensile aluminum alloy that has been compressed under immense forging pressure. By eliminating the separate body halves and joining bolts found in standard calipers, structural flexing is completely eliminated under extreme brake line pressures, ensuring a firm, razor-sharp lever feel.
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4-Piston Synchronized Staggered Pressure: Outfitted with four precision-ground pistons designed to exert perfectly uniform clamping forces across the entire length of the brake pad. This multi-piston array optimizes initial pad bite, distributes heat evenly across the friction face, and prevents uneven pad taper or binding.
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Axial Mount Compatibility: Designed for traditional axial-mount configurations. This setup makes it an excellent choice for custom dual-disc conversions on factory forks utilizing specific aftermarket caliper adaptor brackets, avoiding the need for expensive radial fork bottom replacements.
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Anodized Thermal Coating: Sealed with a rugged, hard-anodized finish that protects the aluminum chassis from corrosive DOT racing fluids, high operating temperatures, and micro-abrasive track debris.
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Integrated Bleed System: Engineered with a high-clearance fluid port and a pre-fitted bleeder nipple positioned at the absolute highest point of the internal fluid channel, making it easy to purge trapped air bubbles during system setup.
Technical Specifications
| Feature | RCB R1 Left-Side Double Caliper Details |
| Caliper Series | R1 Professional Racing Line |
| Cylinder Type | Monoblock Forged (Single-Piece Body) |
| Piston Count | 4-Piston Symmetrical Clamping Array |
| Orientation Fitment | Left Hand (LH) Side Only |
| Setup Configuration | Symmetrical Double Caliper / Dual-Disc Front End |
| Mounting Architecture | Precision Axial Mount |
| Fluid Port Feed | M10 x 1.25mm Thread Pitch |
| Compatible Brake Pad | RCB R1 / S2-D2 Series 4-Piston Pad Profile |
Twin-Caliper Balancing Strategy
When plumbing a left-hand caliper into a double-disc front conversion, maintaining equal hydraulic pressure across both sides of the front wheel is critical to prevent dangerous chassis instability:
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The Master Cylinder Ratio Rule: Standard single-caliper master cylinders (typically 12.7mm or 14mm) do not push enough fluid volume to drive eight total pistons simultaneously. To run a dual R1 caliper setup safely, you must upshift your master cylinder to a high-capacity 15mm or 17mm radial master pump (such as the RCB S1 17mm).
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Fluid Routing (T-Joint vs. Dual Lines): For balanced performance, route a dual-line system using a double banjo bolt directly from the master cylinder down to each caliper, or use an split T-junction block mounted cleanly on the lower triple tree. Avoid looping a single line over the front fender from one caliper to the other, as this can introduce a slight hydraulic delay to the left side.
Installation Guidelines
Because bleeding a dual-caliper system means purging air from eight independent piston cavities, strict attention to detail is required during assembly:
Fitment Note: This caliper is strictly dimensioned and mirrored for Left-Side installation on dual-disc front ends. Attempting to mount this unit on the right side will position the fluid feed ports upside down, making it impossible to bleed air out of the system.
