The automotive aftermarket is filled with a massive array of parts manufacturers, some of them much better than others. Of course, at Vivid Racing, we only offer products that we believe in and know our customers will be happy with; this is why popular Wheel brands like Rota aren’t on our website. When it comes to aftermarket wheels, there are two major manufacturing processes: forged wheels and cast wheels. Almost all cheaper wheels will use a “cast” design while high-end wheels, such as Forgeline, strictly using a “forged” design. Unfortunately, many enthusiasts do not understand the difference between a cast wheel and a forged wheel, and they end up purchasing something not-quite-right for their needs.
A cast wheel is made by pouring molten aluminum into a mold where it is formed to the correct shape and sits there until it cools down. Once the wheel cools down, trimming and drilling are performed. Unfortunately, there is one massive flaw with this method of producing wheels: porosity. Porosity is the physical space inside the material once it has cooled, and it allows for weak points to form. The cheapest workaround for this problem is to use larger tolerances, ultimately making the wheel heavier. This method of wheel manufacturing is very quick and cheap, allowing for mass production of cheap wheels.
Contrary to what some enthusiasts will tell you, cast wheels are not terrible. A properly built cast wheel will indeed weigh more than a forged wheel, but the build quality is typically more than enough for street use and light track use. Heavy track usage is where you’ll see low-quality cast wheels (often replica wheels) fail, resulting in an ugly crash. A high-quality cast wheel will survive heavy track usage, but the heavier design it not ideal.
Unlike cast wheels, forged wheels begin their life as a solid piece metal which is referred to as billet. This solid piece undergoes massive amounts of heat and pressure to form it into the desired shape which is used for different wheel designs. Once this desired shape has been achieved, the forging is placed in a CNC machine where is machined into the exact shape needed.
As we mentioned above, cast wheels are inherently porous; forged wheels aren’t thanks to the heat and pressure they undergo. That strength allows for less material to be used to achieve the desired structural integrity, resulting in a significantly lighter wheel. Often time forged wheels use a “monoblock” design, but they can also use a two-piece or three-piece design which allows for greater fitment flexibility.
Flow Form Wheels
If you’re a wheel nerd like we are, then you probably know there is a middle ground between cast and forged: flow form/flow forged. This starts with a cast wheel that is purposely made narrower than desired. The wheel is then stuck on a machine that spins the wheel while pressing steel roller against the rim area, which compresses and stretches the barrel of the wheel, resulting in forged-like barrel strength and weight. As you may imagine, wheels built using this process fall between the cost of a cast and forged wheel.
Understand that this is a very brief overview of the topic and there is a lot left that we didn’t talk about such as load ratings and elongation. To summarize, remember that cast wheels are cheap but good enough for street use, forged wheels are expensive but will hold up to anything you throw at them, and flow formed wheels are between cast and forged.
Check out some of our most popular wheel brands
- Titan 7
- Volk Racing