A hub motor applies torque directly to the wheel itself with the motor being embedded in the wheel, rather than transferring it through gears, belts, or chains. The motor is surrounded by a ring of polyurethane. The thinner the polyurethane sleeve, the worse the shock absorption and driving. They tend to have less torque and braking power than a belt motor, but require less maintenance, are easier to kick push, and are less noisy. A belt motor connects the wheels to the outer rotor motor via a belt and gear belt system. They are found on more performance boards as they are capable of higher speeds, create massive torque, and allow for more wheel selections. However, belt motors are noisier, harder to kick push, and require maintenance (belt replacement due to wear or tear, belt tensioning and belt alignment).