Many single speed cogs will take a toll on freehub bodies over time. Their narrow nature paired with a whole lotta torque makes for trouble. Our friends in North Carolina developed a brilliant solution the Endless Bike Kick Ass Cog. A full quarter inch wide 6. 35mm at the splines, the Kick Ass Cog simply will not damage your free hub body the way a narrower cog can. It's crafted from high strength 7075 T6 alloy Stronger and harder than most common steels, right here in the U S of A. Endless Bike Kick Ass Cogs are precision machined insuring perfect axial and radial alignment that compliments the superior chain lines that cassette style hubs allow. The specially engineered tooth profile on Kick Ass Cogs improves both cog and chain life while minimizing drive train friction. Because of this, you can expect a smooth, quiet drivetrain no more grittiness.