The most common failure for racing wheels is in the area of the center, either where the center section is welded to the shell, or where the wheel studs come through the wheel. That is why most higher quality wheels add strength to both of those areas.

Back spacing refers to the distance from the outside edge of the rim to the back of the center piece where it meets the hub face. This spacing controls both the track width and the lateral location of the chassis. If we need more or less left side weight, we can use different offset wheels on each side to accomplish those goals. We cannot widen the car beyond the rule specifications, but we can take the track width to the maximum by using lower back spacing.

Another use of split back spacing would be to line up the driveshaft from a top view. A lot of attention is now being paid to reducing universal joint angles, from any view, and the rear end can be relocated laterally by the use of different offset wheels. This may necessitate using odd offset wheels at each end of the car on each side, but if performance is enhanced, then it is worth the trouble it takes to keep track of the wheels.

High amounts of back spacing can result in increased brake rotor heat due to the rotor being placed farther into the wheel shell and out of the flow of air that would normally help cool the brakes. This, in turn, serves to heat the wheel excessively and that heat is transferred to the gas inside the tire. As the gas heats up it expands, and the tire will grow in pressure more than if the rotor was located farther outside the wheel.

Some tracks and sanctioning bodies allow the use of tire pressure bleeders. These units will hold a certain pressure, but pop off and bleed gas as the pressure rises above a pre-set level.

This allows the team to start out the race with pressures closer to the optimum race pressure and still maintain that ideal level once the gas inside the tire expands due to the heat. If a team is not allowed to use bleeders, they must anticipate the rise in pressure and start out with a much lower pressure so that as the heat and gas pressure grows, it will not exceed the optimum pressure needed for producing a proper contact patch footprint.

Some teams use two-valve stems when using a bleeder system so they can fill or deflate the tire with a standard stem while not disturbing the bleeder valve.

There are several types of lug nuts that can be used. The standard type of racing lug nut is fine for everyday use on most short tracks. If pit stops are a must, a spring mounted lug nut is available that stays attached to the wheel and also has a flanged back side which makes it almost impossible to hang and get stuck in the lug socket.

There are specially designed racing lug nut sockets that have wider radii to help prevent the lug nut from getting stuck in the socket, a common occurrence during fast pit stops. These are a necessity for any team, whether pit stops are normally required or not. We never know when an unexpected problem will require a quick stop to replace a flat tire.

Maintain your wheels and inspect them often. Don't let a fatigued or battered wheel cost you a race or possibly a front clip. It would be a good idea to rotate the wheels from side to side occasionally due to the fact that the stress is only being felt on opposite sides of the wheel for left- and right-side wheel mounts. Replace your wheels after hard contact with the wall whether they are bent or not. Small cracks may have developed that the eye cannot detect. After all, it's your investment and especially your driver's health we are most concerned about.

SOURCE
Bassett Wheels Aero Race Wheels
8-88/-895-2376
www.aeroracewheel.com
Paulsen Wheels Diamond Racing Wheels
307 W. Layton Ave.
Milwaukee
WI  53207