SD-X Pro Shimano Type - AlloySD COMPONENTS COG SHIMANO TYPE This aluminum sprocket fits onto hub bodies with the Shimano imprint. Designed for BMX RACE use, this aluminum COG withstands the friction exerted by the chain. The fact that it is made of aluminum allows it to better adapt to Shimano's aluminum splines. It is advisable to use the same material for both the COG and the hubs to prevent marking, which could damage the hub splines. Its contact surface is enlarged to avoid