This refers to the opening in the back of the wheel that centers the wheel on the hub of the car. Since most wheels are mass produced, they have a large centerbore to accommodate different vehicles. If there is a vibration problem, it is recommended that you use hubcentric rings. Hub rings are hard plastic rings that link the wheel to the vehicle. This centers the wheel and makes your wheel hubcentric. Without hub rings it is possible to get vibrations even if the wheel and tire package is completely balanced.
Tech Info About Wheels
The wheel offset is the distance from the hub mounting surface to the centerline of the wheel. There are three types of offsets.
Positive Offset
A positive offset means the mounting surface of the wheel is positioned in front of the true centerline of the wheel. Most factory rims will have this type of offset.
Zero Offset
When the hub mounting surface is centered within the rim, it is known as a zero offset.
Negative Offset
If the hub mounting surface is on the brake side of the center line of the rim, it is considered a negative offset or "deep dish".
A wheel's bolt-circle-diameter is the diameter of an imaginary circle drawn through the center of the wheel's mounting-bolt holes. Bolt patterns vary by vehicle make and model.
If the pattern has an even number of mounting holes (four, six or eight lugs) simply measure from the center of one stud hole directly across the center of the wheel to the center of an opposite stud hole.
With a five-lug pattern, measure from the center of one stud hole to the center of the farthest stud hole, skipping the adjacent hole. The resulting measurement is slightly smaller than the actual bolt-circle diameter.
For example, a vehicle with a bolt pattern of (5 x 120) means this vehicle's hub has five bolts or lugs, which measure 120 millimeters apart from one another diagonally. Below is a chart on how to measure bolt patterns. Wheelfire's fitment program calculates this for you.
Wheelfire has pioneered a fitment program that ensures a 100% proper fit for your vehicle. Our staff is constantly at work making sure wheel specifications are compatible with your vehicle. If you have any upgraded brakes or suspensions please contact our staff before you order.
Plus sizing your wheel and tire package can enhance vehicle performance and looks by allowing fitment of larger diameter rims and lower profile tires. If you make plus sizing changes, keep the overall tire diameter within 3% of the original equipment. Exceeding 3% can lead to a number of problems.
Protect your investment by keeping your wheels clean at all times. Dust or dirt sitting on your wheels might destroy the finish. Always wait until your wheels are cool before cleaning them. Never use steam cleaners or automatic car washes; they can damage your wheels. The best wheel cleaning product is mild soap. Clean one wheel at a time and rinse immediately to avoid soap scum buildup. After the wheels are clean and dry apply a very light coat of wheel wax to protect your wheels from the elements.
It's important to torque the lugs on your wheels properly. The best way to torque your wheels is by hand, using a torque wrench. Wheels are frequently over-torqued onto a vehicle's hub bore. Over-torquing can lead to brake problems or cause the lugs to break off the wheel. Your owner's manual contains the optimal torque specifications for your vehicle. Always re-torque after your first 50 miles.
Most alloy wheels are made in one-, two- or three-piece construction types. One-piece wheels are made in a mold as a single piece of metal. Two-piece wheels are made of separate center and barrel pieces that are welded or bolted together. Three-piece wheels are made of three separate pieces bolted together.
The most common methods of wheel manufacturing are: Forging, Low pressure Casting and Counter Pressure Casting.
Forging
This is the process of forcing a solid billet of aluminum between the forging dies under an extreme amount of pressure. This creates a finished product that is very dense, very strong and therefore very light.
Low Pressure Casting
This is the most common form of rim manufacturing. Liquid metal is poured into a mold and allowed to harden until the finished wheel is cool enough to be taken out of the casting.
Counter Pressure Casting
This method actually sucks the metal into a mold using a vacuum. This reduces impurities making the wheel much stronger than a low pressure cast rim.