A beadlock is a feature found on a high-performance automotive racing wheel. The beadlock is a device that securely fastens the tire to the bead of the wheel, by means of a bolt-on locking ring, to prevent the tire from rolling off of the rim. Available on both the inside and outside of the wheel, the most common beadlock wheel has only a single lock on the outside bead. Popular in a vast array of motor sports from drag racing to rock crawling, the most common form of competition which uses a beadlock wheel is dirt track auto racing. While simulated beadlock wheels are popular on street-driven four-wheel drive vehicles, actual locking beads are not legal for use on any public roadway anywhere.
Many competition vehicles operate with reduced air pressure in their tires to increase traction. This often leads to tires being pulled off of the wheels when sliding sideways in a turn or crawling along the side of a sheer rock wall. In drag racing applications, the wheel is often spun inside the tire due to the tremendous amount of horsepower applied to the tires at the hit of the throttle. By utilizing a beadlock wheel, the tire is clamped to the wheel by sandwiching the bead between the wheel and the locking bead or ring and securing the ring with bolts all around the perimeter of the ring.
Most racing wheels that incorporate a beadlock are constructed from spun aluminum, but there are many steel wheels that also operate with a locking bead. The steel wheels are more durable in some environments in which weight is not as significant a factor. Dirt track racing in some of the lower classes often allows the use of steel beadlock wheels on the right-side rear axle. The upper performance classes, such as late model and sprint cars, often use aluminum wheels equipped with locks on both the inside as well as the outside rear tires with late models often running the locks on all four wheels.
Small versions of the beadlock wheel are manufactured for use on all-terrain vehicles (ATVs) in competitive racing applications. In order to correctly install a tire on the wheel, the locking ring must be accurately torqued to specific manufacturer's specifications. Failure to properly torque the bolts on the locking ring can result in torn tire sidewalls and beads. A loose locking ring also can cause severe vibration and flat tires.