Cast wheels are formed by pouring molten aluminum into a mold and machining the bolt-holes and flanges into spec. Forged wheels are formed by hammering hot or cold steel into shape between a set of dies.
Choosing the Right Wheels - Things You Need to Know
Custom wheels are probably the quickest way to enhance the appearance of your vehicle and give it a unique, personalized style. Aftermarket wheels come in a huge selection of designs and sizes and depending on your plan and budget, they can not only be used to improve the vehicle’s look, but they can also considerably boost overall performance.
So what wheels would be best for your ride?
Well, when it comes to wheel styles, your choice is never ending. But, before talking about the appearance and performance capabilities, there are several important basics you need to know to choose the right wheels for your car, truck, or SUV.
Cast wheels have a uniform grain, where the molecules sit on top of each other and are held together by mechanical adhesion (like a bowl of cooked rice). Forged wheels have an interlocking grain structure that is more difficult to pull apart (like a bowl of spaghetti).
Cast aluminum wheels
This is the most common type of aluminum wheel. The casting of wheels is the process of getting molten aluminum inside a mold to form a wheel. There are different ways this can be accomplished. Please refer to the video at the top of this page.
1- Piece “Monoblock” forged wheels
Monoblock wheels are created by forcing a round bar stock of aerospace-quality aluminum alloy between the forging dies under extreme pressure. Forging is an ultimate technology in one-piece wheels. It creates a finished wheel that is very dense and lightweight. Naturally, the costs of assembly make this type of wheel sit on the higher end of the market price range.
2-piece forged wheels
Two pieced forged wheels divide into another two classes. Some manufacturers bolt the center of the two-piece wheel into a cast or spun rim section, while others weld the center to the hoop on the backside of the wheel. Higher end 2-piece wheels may use forged rims and forged centers, which make them significantly pricier.
3-piece bolted construction forged wheels
Due to the high cost of tooling, and CAD technologies involved, three-piece forged wheels are commonly the most expensive type of wheel construction. The wheel consists of three main pieces: the center, the outer lip and the inner hoop. All parts are normally held together with bolts and sealant applied in or on the assembly to seal the wheel.
Choosing the right size
When changing wheels, be sure to select a replacement with a bolt pattern or circle that matches the OEM pattern of your vehicle. Check what rim widths are recommended by the manufacturer of tires that you consider. To reach the best balance between ride, handling and treadwear, select a rim width in the middle of the manufacturer’s recommended range.
The offset of the rim is what locates the tire/wheel assembly in relation to the suspension. That’s why in order to maintain handling characteristics and avoid extra loads on bushings and ball joints, it is important to keep the front axle offsets on the FWD and AWD vehicles to the OEM specifications. Using the proper positive or negative offset for the vehicle’s rear wheels is important, but less so than using it at the front where the bearing load situation is critical.