Brake Disc for MERCEDES-BENZ, VW Rear ECE R90

This is a solid or vented rear brake disc manufactured from high-carbon alloy cast iron, featuring the following characteristics:

1. Material: Typically made from GG20 high-carbon gray cast iron or higher-grade materials. The high carbon content enhances hardness, wear resistance, and thermal crack resistance, ensuring durability under frequent braking.

2. Manufacturing Process: Precision casting and high-speed dynamic balancing ensure vibration-free operation during high-speed rotation, delivering smooth braking feel.

3. Surface Treatment: Non-friction surfaces (such as hub edges and cooling channel perimeters) are likely coated with high-temperature resistant anti-corrosion coatings (e.g., zinc plating or geometric coatings). This effectively resists rust, extends service life, and maintains visual appeal.

Depending on the original vehicle specifications, it may be a solid disc or a vented disc. Rear vented discs feature internal cooling channels for superior heat dissipation.

Design Focus: Rear brake disc design prioritizes corrosion resistance and compatibility with electronic parking systems, rather than the extreme heat dissipation pursued in front discs.

Additionally:

1. ECE R90 Certification: This is not a marketing concept but a legally mandated requirement. It signifies that during official laboratory testing, the disc's critical data—including braking performance, wear rate, and mechanical strength—must fall within a strict equivalence range compared to Mercedes-Benz/Volkswagen OEM parts. This represents the most rigorous guarantee of performance reliability.

2. Dual-Brand Compatibility: This typically indicates the product covers common models across the Volkswagen Group (e.g., MQB platform) and Mercedes-Benz (e.g., MFA platform) that share similar rear axle brake specifications (e.g., Volkswagen Passat/Tiguan and certain entry-level Mercedes models may use common suppliers or standards). This demonstrates design versatility and manufacturing precision.

3. Addressing Rear-Wheel Pain Points: Rear discs are more prone to rust and seizing due to lower usage frequency. The rust-proof coating directly tackles this issue, reducing maintenance complexity and ensuring the reliability of electronic parking functions during emergencies.

4. Potential Limitations and Considerations

Performance Positioning: Designed for OEM road driving standards, it delivers reliable, safe braking. Its maximum operating temperature range and heat fade resistance are unsuitable for extreme competitive applications like racetracks.

Additionally, to ensure structural integrity, its weight is typically not optimized for extreme lightweighting.

• 100% critical dimensions, runout and DTV inspection 

• Material physical and chemical inspection

• Test shear strength, compressibility, density, flatness and parallelism 

• Test performance and noise/NVH