Rear Sprocket-49T/50T/51T/52T for KTMThe inner ring of the Stealth sprocket is constructed from lightweight aluminum with CAD designed, weight saving cutouts, minimizing unsprung weight. To ensure longevity and durability, the outer ring is made of much more resilient steel. First, the steel ring is coated in a mixture of silver and nickle, which fights corrosion. The second step in the coating process is a black passivation that fills the micro pores in the steel's surface, ensuring