The RK MXU UW-ring Gold 520 chain is known for its exceptionally strong and narrow build with the highest tensile strength in the market. A top choice in MXGP and FIM Hard Enduro championships, it shares the sealing solution commonly used in the Moto3™ category of MotoGP™, offering 5% less friction for increased range and performance. Optimized rubber rings reduce vibration and plate friction, while the rear sprocket, machined from 7075 T6 aluminum, ensures the highest possible wear resistance. The chain slack must be measured at the end of the chain slider, on top of the swingarm. It must be around 45-50 mm (1.8 - 2.0 inches) for the VARG MX, EX and SM.