Beadlock and its Purpose

A bead lock or bead lock is a mechanical device that secures the bead of a tire to the wheel of a vehicle.The tire and wheel are designed so that when the tire is inflated, the tire pressure pushes the bead of the tire against the inside of the rim, leaving the tire on the wheel and the two spinning together.Bead locks are required in situations where the tire pressure is insufficient to hold the tire beads in place.Chains come in a variety of styles.For 4 wheel drive vehicles, a ring with several bolts around the circumference is used to clamp the tire to the wheel.On a motorcycle, a rim lock or bead stop is a curved plate that is tightened by a single bolt. For 4WD vehicles and motorcycles, different types of bead locks are available, which are similar to an air-filled inner tube that presses the tire onto the wheel.

Purpose

The air pressure inside the tire forces the bead against the rim, usually ensuring that the tire and rim rotate as a unit.In typical automotive situations, the air pressure in the tires is sufficient to withstand the shifting forces and rim-slipping forces respectively experienced during sharp cornering and acceleration (including negative acceleration or "braking").Therefore, low tire pressure poses the risk of sudden lack of air, loss of control and even rollover during emergency braking or evasive maneuvers (in addition to often causing the tires to overheat and fail in the future).Modern car tires use a soft rubber compound at the bead to help maintain good rim contact, so special bead locks are not required.

Auto dirt track, off-road racing, dirt bike and motocross tires require high traction, so they have rough treads.However, some riders reduce tire pressure to allow the tread to spread out and create a larger contact patch.This practice poses a safety hazard as there may not be enough pressure to adequately secure the bead to the wheel.The reaction force pushes the tires to one side or the other, especially the outside rear tire when the car is turning around a corner of the track.This can cause the tire bead to come off the rim completely, or enough to cause some air loss.The tire's traction on the ground can also be greater than the friction between the tire and the rim.In this case, the wheel slides around the bead without turning the tire.So bead locks (including adhesives) in one form or another are used to hold the beads of off-road tires securely in place and prevent slippage, even at low inflation pressures.