Often called Spline Drive Chainwheels, Dan's Comp has dozens of choices for your BMX bike. Whether you are looking for a specific color, material strength or tooth number, Dan's Comp has what you are looking for. Spline Drive sprockets were originally developed by Tree Bicycle Co. This style of sprocket uses a steel insert in the center bore that's keyed to fit 48-spline spindles only. Socket Drive sprockets were originally devolved by Odyssey and have a 9-sided center bore that fits Socket Drive cranks only. Both systems eliminate the need for a sprocket bolt, but must be matched exactly to your crank setup.