The patented RingDrive engagement mechanism has made the Chris King BMX hub the hub to beat at tracks all over the world.With 72 pedal positions per rotation you'll always have a choice of the perfect start. The positive, rapid engagement transfers your power instantly to the rear wheel, giving you the confidence you need to win. Now all you have to do is choose which color it is you want to be seen with on the podium. The BMX driveshell rides on a premium quality needle bearing which turns directly on our super-heavy duty steel rear axle. The rear axle has threaded aluminum inserts that are easy to replace in case your threads get messed up, WITHOUT throwing away the axle. This hub is built to last a lifetime. Consider it an investment in your lifelong passion for BMX. Chris King BMX hubs are sold with a 16T stainless steel King Cog. Additional stainless steel cogs are available from 12t-20t.