RCB S2 PLUS SERIES ALLOY FLOATING BRAKE DISC 298MM R15 V3/V4/M MT15 XSR

RCB S2+ Series Alloy Floating Brake Disc (298mm) is a premium, track-ready braking upgrade designed specifically for the Yamaha YZF-R15 V3, V4, and R15M.

As part of RCB’s high-performance S2+ Series, this rotor expands the factory braking surface to a generous 298mm diameter. It replaces the rigid, stamped stock brake disc with a true, full-floating two-piece system. This configuration dramatically improves stopping power, provides razor-sharp initial bite, and completely eliminates brake fade under aggressive street riding or heavy track-day lap conditions.

Key Features

• True Full-Floating Architecture: The brake disc is engineered in two separate pieces connected by heavy-duty stainless steel floating pins/buttons. This design allows the outer steel braking ring to expand and contract freely when exposed to extreme thermal stress, preventing warping, distortion, and uneven pad wear.

• High-Friction Stainless Steel Braking Ring: The outer rotor ring is machined from premium, induction-hardened stainless steel. It features an aggressive, computer-optimized ventilation hole pattern that continuously clears away hot brake dust, gases, and water for consistent all-weather stopping bite.

• Aviation-Grade Billet Alloy Center Hub: The inner carrier ring is CNC-machined from ultra-lightweight, high-strength aircraft aluminum alloy. By reducing unsprung weight and rotational mass, it enhances front suspension responsiveness and allows for quicker side-to-side steering transitions.

• Enhanced Heat Dissipation: The floating design eliminates the structural bridge through which heat conducts into the front wheel hub. Combined with the slotted and drilled cooling vents, it runs significantly cooler than OEM rotors, keeping brake fluid temperatures low and preventing a spongy lever feel.

• Aggressive Racing Aesthetic: Finished with hard-anodized protective coatings on the center alloy hub, the S2+ Series disc adds a high-tech, race-bred appearance that beautifully matches the premium styling of the R15 V3, V4, and R15M.

Technical Specifications

Performance Benefits

Factory R15 brake setups use a smaller, fixed steel rotor that can easily overheat and expand unevenly during spirited riding down mountain passes or under hard track-entry braking. Moving up to the RCB 298mm S2+ Floating Disc shifts your braking leverage outward. This gives your caliper greater mechanical advantage, shortening your stopping distances while giving your front brake lever an incredibly communicative, linear feedback loop.

Installation & Maintenance Guidelines

1. Direct Bolt-on Hub Fitment: The inner alloy hub features the exact bolt-hole PCD pattern as the factory R15 wheel hub for a seamless mount. Note: Because this oversized 298mm rotor is larger than the stock diameter, you must use the caliper extension spacer bracket included in the kit to correctly space out your front brake caliper.

2. Always Install Fresh Brake Pads: Never pair a brand-new performance floating disc with old, unevenly worn brake pads. Always install a fresh set of premium sintered or ceramic brake pads to ensure even bedding and prevent scoring the new rotor surface.

3. Use New Fasteners & Threadlocker: Clean the hub mounting threads thoroughly. Install your disc bolts and apply a drop of medium-strength blue threadlocker (e.g., Loctite 242) to every bolt, tightening them in a cross-star pattern to the manufacturer’s exact torque specifications.

4. Perform a Proper Bedding-In Cycle: For the first 50 to 100 kilometers, avoid sudden emergency-style braking. Perform a series of gentle, controlled decelerations from 60 km/h down to 10 km/h to evenly transfer a layer of pad material onto the steel ring for maximum friction coefficients.