A beadlock or bead lock is a mechanical device that secures the bead of a tire to the wheel of a vehicle. Tires and wheels are designed so that, when the tire is inflated, the tire pressure pushes the bead of the tire against the inside of the wheel rim so that the tire stays on the wheel and the two rotate together. In situations where tire pressure is insufficient to hold the bead of the tire in place, a beadlock is needed.
There are several styles of beadlocks. For 4-wheel drive vehicles, a ring with a number of bolts around the circumference is used to clamp the tire to the wheel. For motorcycles, a rim lock or bead stopper is a curved plate tightened by a single bolt. For both 4-wheel drive vehicles and motorcycles, a different style of beadlock can be used that is similar to an inner tube which is inflated to press the tire against the wheel.