You’ve decided to finally get some new wheels. You’ve done some research, decided you want single piece, thought about how many spokes you want, the color, and thought about a good offset for your fitment. But you are still curious about one thing. Which wheel type is best for you and your application? What the heck is cast, flow formed and forged? Well, UroTuning is here to help you choose!
What are alloy wheels?
Let’s start with exactly what ARE alloy wheels? Alloy wheels nowadays are typically made from a mix of aluminum and nickel blend. This generally produces a metal that is much stronger than pure metals. Not to mention, they are lighter, generally look a lot better, and withstand heat more than the typical steelies we’ve all seen before. Early alloy wheels were made mostly from magnesium until the mid 60’s. With the advancements of aluminum-casting refinements, manufacturers saw they were able to make safer wheels that were not nearly as brittle. Once aluminum casting improvements became more widely adopted, aluminum quickly took place of magnesium regarding low cost high-performance wheels for motorsports. SO, when it comes to actually making wheels, there are 3 popular manufacturing processes, cast, flow formed, and forged.
Cast wheels are the the most common manufacturing type that you will see. Molten aluminum is poured into a mould to be shaped, cooled, machined, drilled, and then trimmed. This is probably the easiest and least expensive way to make a wheel. The trade-off in this process is the chance of more porosity, or inconsistency in the structure which can lead to less structural integrity and possible cracking. The process also requires the use of more material which in turn equals more weight! Cast wheels are designed for a lower load rating and can break if pushed too far past those limits. The advantage of this process however is that it is fast and inexpensive. The disadvantages are the possibility of cracks or bends from pushing them too far past their limits. Keep in mind, cast wheels are still a quality choice. There is a reason why the vast majority of OEM wheels are cast wheels. We definitely love the Rotiform SGN's we ran on our Mk8 R.
Flow Formed Wheels
The next process is flow formed wheels. It’s considered an upgrade to the cast process, and it can go by many names. It’s also known as flow forged or forged hybrid. The thing is, these aren’t actually forged. The process is similar to start, the wheel face is cast, and the barrel not as wide as a typical cast wheel. There may be some variations in the overall process, but typically the barrel is heated and spun while stretching and compressing the inner barrel to the desired size. The process of heat and pressure helps to create strength while using less material which is lighter but at the same time much stronger. This process greatly improves the strength which is similar to the forging process. Being a lighter and stronger wheel makes Flow formed wheels great for the track where every tenth matters. Having less rotating mass will equal faster acceleration and better braking. Weekend racers really love flow formed wheels for this very reason. In fact, if you go out to our parking lot, you will see all sorts of flow formed wheels from Konig, ESR, Rohana and so much more. They are an excellent middle ground between cheaper cast and expensive forged wheels.
Finally, we have the forged wheel process. This creates the strongest, lightest, and you guessed it, the most expensive wheel! Every forged wheel starts off as a solid chunk of metal, also known as billet metal, unlike cast or flow formed which technically starts with a cast wheel. The billet metal is then super heated to extreme temperatures and pressure is applied to forge its shape into a disc. Finishing touches are added as the disc is spun and flow formed into what is known as a spun blank. Once this is completed it’s heat treated to condition it, then it’s lathe turned into the customers final requested configuration. This process causes the wheels to be extremely strong due to refining the metal grain. An advantage to this technique means potential failure points that affect typical cast wheels like, porosity, cavities, and more are eliminated. A forged wheel will instead bend, rather than break due to the construction method. It resists cracks and is often times able to be repaired more easily. There are also more design options available due to the sheer strength of the construction method. They can be fully customized to your order. The forged process translates to increased longevity, increased resistance against wear and tear, and increased performance and handling. These are generally the go-to for the track due to being able to be repaired if necessary, their strength, weight, and higher load rating. Some great examples that we carry are from Neuspeed and Rotiform. The greater vehicle performance and enhanced fuel efficiency can’t be ignored.
There you have it. The simple answer, cast wheels are generally more budget friendly, a bit heavier but a solid choice. Flow Formed is the upgrade to cast being stronger and lighter with tons of great designs and great for the street and track. And finally, forged wheels, the cream of the crop being the strongest, lightest, highly versatile due to its construction process. All great choices depending on what you are wanting to do and your budget.
We hope that helps you in your decision for your new set of wheels. Whether for just the street, or to include the track, cast, flow formed, or forged there are tons and tons of fantastic options for whichever direction you decide to go for your personal build or the application. If you have any other questions, don’t hesitate to reach out as we are always willing to help! Our sales team will help you make the best decision for you.