Motorcycle rear brake disc

B2B buyers should prioritize High-Carbon Stainless Steel (SUS420/410) or Heat-Treated Carbon Steel. These materials offer the best balance of friction coefficient, thermal stability, and corrosion resistance. For racing or heavy-duty applications, ensure the disc has a hardness rating of HRC 35-38 to prevent premature warping under high temperatures.

Drilled holes are essential for heat dissipation and weight reduction, while slotted designs help clear water and debris from the pad surface. For off-road motorcycles, wave-shaped (petal) designs are preferred as they provide better self-cleaning properties. Ensure the hole chamfering is precise to avoid stress cracks during rapid cooling cycles.

To ensure safety and legal entry into major markets, verify that the supplier holds ISO 9001 for manufacturing quality and IATF 16949 for automotive-grade components. For the European market, look for TÜV certification or ABE (Allgemeine Betriebserlaubnis) approval, which guarantees the disc meets strict braking distance and structural integrity requirements.

Always request a technical drawing or CAD file to verify the Pitch Circle Diameter (PCD), the number of bolt holes, the inner hub diameter, and the thickness (usually 4mm to 6mm). A variance of even 0.5mm in thickness or offset can lead to catastrophic brake failure or fitment issues.

The biggest risks are material substitution (using low-grade steel that warps) and dimensional inaccuracy. To mitigate this, use Made-in-China.com's Secured Trading services and insist on a third-party pre-shipment inspection (PSI) to verify hardness and run-out tolerances (which should be <0.1mm).

Request a 'Golden Sample' and have it tested in a local lab for chemical composition. In your contract, specify that bulk production must match the sample's metallurgical properties. Negotiate a staged payment plan (e.g., 30/70) where the final balance is only released after a successful quality report from an inspector.

Brake discs are heavy and prone to surface rust. Ensure the supplier uses VCI (Volatile Corrosion Inhibitor) paper or anti-rust oil coating before vacuum sealing. For shipping, use reinforced double-wall corrugated boxes with individual dividers to prevent discs from knocking against each other, which can cause micro-fractures.

Check the HS Code (typically 8714.10) for your specific country to calculate import duties. Be aware of Anti-Dumping Duties (ADD) that may apply to steel products in certain regions. Always request a Certificate of Origin (CO) from your supplier to take advantage of any Free Trade Agreements (FTA) that could reduce your tax burden.