The term "wheel" is sometimes vague, but typically refers to the overall components which make up one piece that comes off when the lug nuts are removed. However, the actual "wheel" itself is the metal portion within the tire that allows the tire to mount to it, and is connected to the wheel hub.
Wheels are the metal support for the rubber of the tire, and means of conntection to the axel. Instead of being a weighty piece of metal, the wheel is composed of spokes which connect the outside portion to the mounting area in the middle. The number and thickness of the spokes vary by design, and are usually designed to be visually appealing as well.
The rim is where the edge of the tire sits on the wheel. Some rims have a flat surface beyond the point where the tire sits so weight attachments can be added for balancing.
The drop-center design is used in most wheels to aid installers in removing and installing tires on the wheel. The tire bead, the innermost portion of the tire, is more narrow than the rim of the wheel. In order to get the tire off the wheel, one of the tire's beads is placed partially in the drop-center, while the other side is lifted over the rim with a tool. The drop-center is used in installation as well.
Performance oriented wheels are almost always designed to be lighter than standard ones, since they are part of the unsprung weight. Some of them are also designed to be aerodynamic, and/or to draw in or blow out air in some special racing vehicles. Performance wheels often cost more since they have to made out of strong, lightweight materials, and have strong archetexture to allow as little material as possible to further reduce the weight.
Should you Buy a Spare Set of Wheels?
Purchasing a full spare set of wheels allows you to change tires with ease, but it has a few drawbacks.
Parts of Wheels & Tires
Wheels and tires are made up of a number of components, as listed below:
There are a number of things you can do to maintain your wheels, which you can find in the links below.
- Checking The Pressure of Your Tires
- Checking Wheels for Play
- Finding a Leak
- Installing New Tires on Your Rims
- Rotating Your Tires
Wheels and tires aren't perfectly shaped, round, or weighted, but they are usually quite close. A wheel balancing machine allows an installer to balance the tire/wheel combination so that it doesn't vibrate when the vehicle is driving with it.