Racing rims are automobile wheels that are generally lightweight and very round. A racing wheel, or racing rims as they are sometimes called, are machined to exacting quality standards to ensure the most round wheel possible in order to avoid unwanted vibration at high speeds. The center bolt hole region of racing rims is typically stronger than that of a street wheel to ensure that the center of the wheel is not ripped out or damaged by the extreme power applied by the race vehicle. Racing rims also frequently incorporate a bead lock or double-bead lock ring to retain the tire in the event of a blow-out as well as to prevent the wheel from spinning inside of the tire upon acceleration. A racing wheel is often extremely wide to fit the oversized rear race tires or very narrow to fit the extremely skinny front racing tires of a drag-racing vehicle.
Science has proven that lightweight objects accelerate faster than heavy-weight items. This understanding has resulted in racing rim manufacturers creating the lightest wheels possible for competition use. Constructed of lightweight aluminum, steel or magnesium, racing rims are designed to give the utmost in strength while remaining as light as possible. This often makes the wheels subject to damage through light contact, but this is a trade-off that most racing teams are willing to make to have lightweight racing rims. Often, valve stems on racing wheels are positioned to the inside of the wheel to prevent the valve stem from breaking and creating a flat tire if it makes contact with another vehicle.
To add strength to the center of the wheel, most racers use extra-large lug nuts to fasten the race wheels to the vehicle. By using the extra-large lug nuts, the side load of the wheel is spread out over a larger area and prevents the wheel from ripping out and tearing over the lug nuts. Some racing rims are equipped with directional vent holes in the center of the wheel. These vent holes suck cool air into the wheel and are helpful in cooling the brake pads as well as the tire in very high-speed racing applications.
Racing wheels, like most racing parts, are very strong. They are not, however, tested and approved for use on public roads. Therefore, racing rims are not legal for use on a street-driven vehicle in most areas. The lightweight design of these racing-only components would most likely break upon contact with a pothole or repeated bumps. Race tracks are ground very flat and smooth to prevent this from happening to racing rims during a competition.