RK 520Zxw Chains RK 520Zxw Chains are specifically designed for today's heavy, high horsepower bikes and extended swingarms. Made with the best reinforced components and RK's original XW-Ring for maximum strength and wear-life. Features: Tensile Strength: 9,450 lbs Max CC Rating: 1,200cc Master Link Included: Rivet type ZXW is perfect for large, high-displacement and extended swingarm machines.