lis2k said:
3 piece forged wheels are not made of the same kind of metal as one piece forged wheels. 3 piece wheels if you ever notice, the lip and center if both polished will never have the same finish. They are different types of aluminum. While a 1 piece forged wheel may be made of the same kind of metal as the center piece of a 3 piece wheel, the barrell and lip are another kind of metal. I am no metal expert, but call up HRE, Kinesis, Simmons, e.t.c. and ask them about the different types of metals they use and you will be quite surprised. 1 piece forged wheels will definitly be lighter than 3 piece wheels though.
A lot do.. But some of them use forged 6061 Aluminum alloy in both the center as well as the rimshell. Right now it is one of the most durable Aluminum alloys being used on the market.
Simply put, 3-Piece wheels gives you more flexibility in terms of widths, offsets and lip.
Just to clarify, the Volk GT series wheels are not 3-piece. They all use cast centers with spun forged aluminum alloy barrel (a 2-piece wheel design).
Casting allows for a more complex design than forging. That is why you get the awesome and much copied wheel designs from Rays and Work.
The above companies as well as PIAA and SSR have also developed systems to allow for a process where the casting is semi-forged with lighter pressures to align the crystal structure and still able to get complex designs.
Poorly cast wheels like you see on most Donks, Bubbles and Boxes are extremely heavy and are prone to cracking. It gets its strength from sheer mass. Personally would rather have a wheel bend than crack.
Single piece forged wheels are lighter than their 2- or 3-piece counterpart.. not necessarily stronger. Each company has a certain criteria(s) for strength and design wheels accordingly. Something to keep in mind, there are a lot of companies with super light weight wheels that will not last 2 seasons of racing let alone a full single season. And when I say racing.. I mean road racing, grip racing.. whatever you want to call it. The racing that lasts for more than 15 minutes, has left and right turns as well as braking, berms, and pit stops.
In the early era of 3-piece wheels, people were getting expensive magnesum centers built. And instead of having to have more centers built to replace a wheel, they just replace the cheaper aluminum outer rimshells.
The whole concept of 3-piece wheels is to be able to replace the inner or outer rimshell depending on damage. Companies such as but not limited to BBS and Volk have very tight production tolerances, assembly methods, and especially patented methods that they will not risk their reputation nor risk losing market share by trying to repair a damaged wheel. Besides, it would involve sending it back to their respective home countries to repair.. negating any savings of replacing a part of the wheel.
And having someone other than the manufacture alter a wheel can have disastrous results (See thread regarding the broken wheel - no one ever pointed out that the owner of the wheels had literally altered the physical properties of the wheel trying to modify it instead of doing the proper thing and ordering new ones).
Right now the pinnacle of racing wheels are forged Magnesium wheels.
Regards,
James R