BMW X4 M40i / M40d (G02) Carbon Ceramic Brakes Kit

Lightweight

Half the Weight, Sharper Handling. StopFlex carbon-ceramic rotors shed roughly half the mass of equivalent iron discs. This massive drop in unsprung weight instantly transforms your chassis, delivering sharper turn-in response and a significantly more refined road feel.

High-Temp Resistance

Minimal Brake Fade at 900°C (1652°F). While traditional iron rotors severely fade under heavy track loads, our CCB matrix holds a stable 0.30μ friction coefficient even at 900°C (1652°F). You get consistent, predictable stopping power when things get dangerously hot.

Corrosion Resistance

100% Rust-Free Durability. Say goodbye to flash rust after a car wash or heavy rain. The carbon-silicon carbide material is naturally impervious to corrosion, ensuring your brake rotors look completely clean and pristine no matter the weather conditions.

Long Lifespan

250,000+ km (155,000+ mi) Lifespan. Iron rotors typically require replacement around 100,000 km (62,000 mi). In normal street driving conditions, a StopFlex CCB rotor can easily last 250,000 to 300,000 km (155,000 to 186,000 mi), effectively outlasting the vehicle itself.

Ultra-Low Dust

Ultra-Low Visible Brake Dust. Heavy black dust destroying your wheel finish is a thing of the past. When paired with our matched StopFlex pads, these rotors generate virtually zero visible brake dust, keeping your premium wheels spotless for much longer.

Premium Visual Finish

Premium Mirror-Like Finish. StopFlex utilizes a patented ceramic formula that cures with a distinct crackle pattern. The surface is machined dead-smooth for high reflectivity, providing a premium aesthetic behind open wheels under the right lighting.

High Normal-Temp Friction

Strong Initial Bite (0.40μ+). With matched StopFlex pads, normal-temperature friction can exceed 0.40μ for a firmer pedal feel and strong initial bite.

Long-Fiber Construction

Continuous Long-Fiber Strength. StopFlex utilizes a continuous long-fiber 3D matrix. This structure is significantly stronger and offers higher thermal conductivity than standard chopped-fiber OEM CCM discs.

Cold First-Stop Confidence

Reliable Cold-Bite at -20°C (-4°F). Coated street rotors still deliver normal first-stop braking at -20°C (-4°F). Uncoated motorsport rotors are the exception.

Street Spec

Ceramic coating + cross-drilled face + large cooling channels.

Use the smaller matched option when your X4 M40i/M40d is mainly a daily driver and you want the simplest correct-size upgrade.

Track-Day Spec

Ceramic coating + blank face + honeycomb cooling channels.

Choose the larger front setup if your G02 already uses 374mm fronts or sees frequent high-speed, repeated braking.

Motorsport Spec

No coating + blank face + honeycomb cooling channels. Not for normal street use.

For the hardest sustained use, pair the largest compatible front setup with proper pad, fluid, and airflow planning.