Wheel Tech 102: Wheel Construction
A wheel has a rim and when someone says "rim" they often mean "wheel." Wheels and rims, rims and wheels. It can be confusing, but really, they are pretty much synonymous with one another unless you're talking to an engineer or technician about something very specific. But whether you call it a "wheel" or "rims," the manufacturing process is very, very important, because it sets the baseline for durability, weight, strength, and appearance.
Alloy Wheels vs. Steel WheelsPretty much every OEM wheel you're going to find is made of an alloy composed of aluminum and other metallic substances. Alloy wheels are more durable, stronger, and better looking than a steel wheel. Durability means less of a chance of cracking or corroding under normal conditions, strength means longevity, and appearance means style. Alloys are also lighter than steel, which directly leads to responsiveness, handling, and acceleration.
One-, Two-, and Three-Piece WheelsThe vast majority of wheels are one-piece wheels, which means they were manufactured using a single mold. Some wheels come in two- or three-piece versions, wherein there are multiple pieces molded separately (a center and barrel, or a center, inside, and outside rim pieces, respectively) and are welded and/or bolted together using high quality fasteners to ensure there's no separation.
Forged WheelsForged wheels are stronger and lighter than your standard aluminum wheel, because they are subjected to forced compression combined with heat.
Roll ForgingA subset of forging, roll forging sees the use of a metal blank run through rollers. Less aluminum is used in this process, which reduces the weight of the wheel (increasing performance), but maintaining its strength and durability.
Low Pressure and Counter Pressure CastingLow pressure casting is the most common form of wheel manufacturing currently used. This is simply the act of pouring liquid metal into a mold and cooling it to harden into its final shape. Counter pressure casting instead sucks the metal into the mold using a vacuum rather than having it poured in, which reduces impurities and increases material strength of the wheel.
Lug Nuts, Lug Bolts, and Wheel LocksThough not a physical part of the wheel during the manufacturing process, lug nuts and bolts are absolutely integral when considering the durability, strength, and appearance of your wheels. Bolts come in three common types:
- acorn seat (conical)
- ball seat (radius)
- mag shank seat