RZMA M402 Large Four-Piston Opposed Disc Brake Caliper

Upgrade your motorcycle or electric motorcycle's braking system with the RZMA M402 Large Abalone Four-Piston Disc Brake Caliper. Engineered for riders who demand precise, confident braking at every speed, this fully CNC-machined aluminum alloy caliper delivers powerful, linear stopping performance with a sleek, high-end aesthetic to match.

Key Features

1. Four-Piston Synchronous Clamping for Maximum Braking Force

The classic large abalone opposed four-piston structure clamps both sides of the brake rotor simultaneously, ensuring balanced, even pad wear and consistent stopping power. Gentle application gives smooth, linear feedback, while firm braking locks instantly — giving you total confidence at high speeds and significantly reducing stopping distances.

2. Full CNC Aluminum Alloy Forged Body — Lightweight & High-Strength

Machined from a single billet of aluminum alloy via precision CNC milling — not die-cast or spliced — this caliper delivers superior rigidity without added unsprung weight. The anodized bright-surface finish is corrosion-resistant and rust-proof, keeping your caliper looking sharp and performing reliably over the long haul.

3. Upgraded Dual Sealing System

An imported high-temperature-resistant oil seal combined with a dust-proof outer seal creates a robust two-layer barrier against mud, water, and debris. Even during prolonged high-speed or mountain downhill riding, the system resists vapor lock and leaks, keeping braking performance stable and reducing long-term maintenance needs.

4. Built-In High-Performance Sintered Brake Pads

Included sintered brake pads offer stable friction across a wide temperature range — no slip in cold conditions, no fade under heat. Braking is whisper-quiet with zero harsh squealing, and the short break-in cycle means you can ride at full capacity almost immediately after installation.

5. Universal Fitment — Easy Bolt-On Installation

Standard mounting holes make this caliper a direct bolt-on upgrade for most electric motorcycles and riding motorcycles. Included fixing screws allow straightforward assembly without grinding, machining, or special adapter brackets — beginner-friendly and quick to install.

6. Premium Appearance Upgrade

Mirror-polished silver precision-cut patterns, branded logo relief engraving, and a strong mechanical aesthetic instantly elevate your wheel assembly's visual appeal. Replacing factory thin calipers with the M402 adds a competition-grade look to any build.

Specifications

Model: RZMA M402 (jk26)
Material: Billet CNC Aluminum Alloy
Piston Configuration: Four-piston opposed (large abalone style)
Brake Pads: Sintered (included)
Finish: Anodized, mirror-cut pattern
Compatibility: Electric motorcycles & riding motorcycles (standard mounting)
Country of Origin: Made in China

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Safety & Standards Reference

For guidance on motorcycle braking system standards and road safety, refer to the National Highway Traffic Safety Administration (NHTSA) and the U.S. Consumer Product Safety Commission (CPSC) for consumer product safety information.

Learn more: Disc brake

Frequently Asked Questions

Q: Is the RZMA M402 four-piston brake caliper compatible with my motorcycle?

A: The M402 uses standard mounting hole spacing, making it compatible with most electric motorcycles and riding motorcycles. No special adapter bracket or grinding is required — it bolts directly onto standard mounts. We recommend verifying your rotor diameter and caliper bracket spacing before ordering to ensure a perfect fit.

Q: Does the M402 disc brake caliper include brake pads?

A: Yes. The RZMA M402 comes with high-performance sintered brake pads pre-matched to the caliper. These pads are ready to use out of the box with a short break-in period, so you can ride at full capacity quickly after installation.

Q: How does CNC billet construction compare to die-cast calipers?

A: CNC billet aluminum calipers are machined from a single solid block of aluminum alloy, resulting in superior structural rigidity, tighter tolerances, and less risk of porosity or micro-fractures compared to die-cast parts. This means the M402 is stronger, more durable, and better able to withstand the heat and stress of repeated hard braking.

Q: Will the M402 caliper fit a 160mm or 180mm rotor?

A: The M402 is designed to work with standard disc brake rotor sizes commonly used on electric and riding motorcycles. Please check your rotor diameter and confirm compatibility with your existing setup or consult your vehicle's specifications before purchasing.