RK Chains 428 Mxz4 Chain Designed to meet the rigorous demands of motocross and supercross, the RK 428 Mxz4 Chain offers unparalleled strength and durability for competitive racing. Crafted from high-quality Chromoly steel, it features seamless rollers and bushings, ensuring smooth performance in extreme conditions. The Chromized pins significantly increase wear resistance, absorbing shock loads efficiently. With its exclusive HIT process, every component is heat-treated for supreme toughness. Ideal for 428 pitch applications on smaller displacement bikes, it's a racing-only chain, not suited for street use. Features: 428 pitch racing chain designed for motocross and supercross use Chromoly steel construction for superior strength and durability Seamless rollers and bushings for smooth operation and reduced wear Chromized pins offer more than 2x wear resistance over standard non-sealed chains HIT (Heat Induction Transfer) heat treatment for enhanced toughness High shock-load absorption for extreme riding conditions Tensile strength: 6,400 lbs Maximum engine size: 150cc off-road Maximum horsepower rating: 40 HP Weight: 2.21 lbs Maximum chain width: 20.2 mm Includes clip-type master link Not recommended for street use