Yokohama

Customizing


High Performance Wheels

Selling high performance tires provides a great opportunity to include high performance wheels as an important and profitable part of your business. High performance wheels are available for most applications to both improve the appearance of a vehicle and complement the performance of replacement tires.

To assure correct fitment, proper replacement wheel size, dimension and load-carrying capacity are critical. Always consult the wheel manufacturer/distributor's literature to verify that the desired wheel and tire combination is an acceptable application for the vehicle.

Wheel Width

Choosing the wheel's width is important to assuring customer satisfaction. In addition to correct fitment, the wheel's width also influences handling and ride quality. Always choose a rim width within the range of the tire's acceptable rim width specifications.

  • Choosing a wider rim: increases vehicular stability, steering response and cornering ability. A rule of thumb is to use a rim width 90% as wide as the tread width (not section width) of a performance tire for street applications. This provides a good balance between performance and ride quality. Always be sure that the chosen rim width is within the tire's range of acceptable rim width specifications.
  • Choosing a narrow rim: results in an improvement in ride quality, but may sacrifice the tire's ultimate performance capabilities.
  • Choosing a mid-range rim widtth: provides a balance between handling capabilities and ride quality.

An example of a proper application would be to use a 15" x 6" wheel for a 205/70VR15 tire. Never attempt to mix millimetric wheels and tires with standard inch wheels and tires. An improper application would be mounting a 200/60R390 size tire on any 15" wheel. A 390mm tire is designed to fit on a wheel with a diameter of approximately 15.35" with a non-standard bead seat.

Warning: According to RMA guidelines, there is danger in installing a tire of one rim diameter on a rim of a different rim diameter. Always replace a tire on a rim with another tire of exactly the same rim diameter designation and suffix letters. For example: a 16" tire goes with a 16" rim. Never mount a 16" size diameter tire on a 16.5" rim. While it is possible to pass a 16" diameter tire over the lip or flange of a 16.5" size diameter rim, it cannot be inflated enough to position itself against the rim flange. If an attempt is made to seat the tire bead by inflating, the tire bead will break with explosive force and could cause serious injury or death.

High Performance Wheels

 

Wheel Backspace

The following are various high performance wheel measurements that play an important role in determining tire and wheel fitment:





Bolt Circle

When considering custom wheels for a specific application, it is imperative that the wheel's bolt circle matches that of the intended vehicle. The bolt circle is the diameter of an imaginary circle formed by the centers of the wheel lugs. The bolt circle reference is designed to accommodate 4-, 5-, 6- and 8-lug patterns. A bolt circle marked 5-100 (Chevrolet Cavalier, for example) indicates a 5-lug pattern with a diameter of 100mm. Consult the rim manufacturer's literature for bolt circle information for each application. If there is no information available, you may need to calculate the bolt circle.

 

This is the distance from the back edge of the wheel to the hub mounting surface. To determine the wheel backspace:

  • Position the wheel face down.
  • Lay a straight-edge across the back of the wheel.
  • Measure the distance from the straight-edge to the wheel's hub mounting surface.

Wheel Offset

This is the distance from the back edge of the wheel to the hub mounting surface. To determine the wheel backspace:

  • Zero offset: The hub mounting surface is even with the centerline of the wheel.
  • Positive offset: The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front-wheel drive cars.
  • Negative offset: The hub mounting surface is toward the back or brake side of the wheel's centerline. "Deep dish" wheels are typically negative offset. Offset can be calculated by positioning the wheel on a flat surface and measuring its overall width and backspace as shown below. Divide the overall width by two, then subtract this result from the backspace value.

4-, 6-, or 8-lug patterns:

Record the distance between the centers of two holes directly opposite one another.

5-lug pattern:

Estimate by measuring from the center of one hole to the far side (outside, not center) of a non-adjacent hole. The diagram below illustrates the proper measuring methods.



Hub-Centricity vs. Lug-Centricity

Another important consideration in the proper selection of custom wheels is the concept of hub-centricity. This refers to a situation where the center bore hole of the wheel exactly matches the vehicle's hub diameter. In other words, if the vehicle's hub diameter is 56mm (e.g., Acura Integra), the wheel's center bore hole should be designed to match it perfectly.

Hub-Centricity

 

Lug-Centricity

When automobile manufacturers design a vehicle, they utilize hub-centric wheels so that:

  • The wheels are positioned very precisely on the car.
  • The possibility of shifting while being mounted is minimized


 

The alternative to a hub-centric wheel is known as lug-centric:

  • The wheels are located solely by the lug nuts rather than the wheel hub.
  • As the lug nuts are tightened, they adjust the wheel's position relative to the hub, thus centering the wheel.
  • Properly torqued, the lug nuts continue to keep the wheel centered as the vehicle is driven.

Lug-centric wheels require extra care in mounting on a vehicle. When using shouldered nuts instead of tapered nuts, take extra care to properly locate the wheel. Never use air tools to install high performance wheels! Always use a torque wrench and follow accepted tightening procedures.