Renthal Twinring Rear Sprocket 48T For Yamaha YZ/WR-250/450

Renthal's TwinRing sprockets are the longest lasting, most durable sprockets you can buy. It took five years of extensive R&D to bring you this high-strength, yet lightweight design. The TwinRing design combines a specially enhanced 7075 T6 aluminum alloy center and an ultra-high strength electroless nickel coated steel outer ring. By combining these two materials, Rental created a sprocket that is lighter than steel but more durable than traditional aluminum sprockets. The outer ring is heat-expanded at 200? Centigrade and the fitted over then inner ring. This interference fit design is combined the wave pattern of the inner disc to ensure a permanent bond for the life of the sprocket. Flat socket head screws add additional strength to the sprocket for side impact resistance. The unique flat face design keeps weight to a minimum and prevents fouling on the chain guide.