Every technology has a limit. Cast aluminum wheels were a big improvement over steel wheels, however when it comes to performance, there are other technologies like flow-forming or forging that surpass a standard cast wheel. These higher level technologies will allow a reduction in weight (while maintaining the stiffness and durability) that will improve vehicle performance.
Flow-forming has been an important production technology at BBS for the past 20 years. Although many other wheel companies talk about “Flow-forming” as if it is something new, BBS introduced first aftermarket flow-formed wheel back in 1996.
Current BBS aftermarket designs that benefit from the "Flow Forming" process are CI-R CH, CH-R, CHRII, CX-R, RX-R and SV. BBS supplies cast flow-formed wheels for many high performance OEM manufacturers including: BMW, Audi, Mercedes and Porsche. Also, some factory racing programs from BMW, Ferrari and Ford have selected a BBS cast flow-formed product specifically for track use.
Explanation : "Flow Forming" is a procedure that uses 3 hydraulic rollers and tremendous pressure to ”Form” the inner rim area. Through this process, the hydraulic rollers force the cast material to conform to the profile of the massive steel tooling. During the process, the full width of the rim is created.
Computer simulation accelerates and optimizes the development process and provides the basis for the first prototypes. After extensive testing, the appropriate adjustments are made and the exact surface finish and color are selected before the new wheel goes into series production.
Benefit: The pressure used in this process actually changes the mechanical properties and the grain structure of the cast rim area to have strength, stiffness and impact values closer to that of a forged rim. "Flow Forming" also helps reduce the weight up to 15% when compared to a standard cast wheel. The overall “Stiffness to Weight Ratio” is very good and can deliver a high level of performance at a cost that is much lower than a forged wheel.
With BBS patented rim protector made of polished stainless steel, you can permanently safeguard the high-quality look of your wheels. Should damage occur, the rim protector is available as a replaceable spare part and can be exchanged easily without having to replace the entire rim or remove the tire.
Milling the spokes allows BBS to hit just the right balance between wheel weight and stability. Using a special multi-axis CNC milling process, the area of the spokes that do not contribute to its stability can be removed. Before destructive testing is done in our test facility, a computer simulation of the wheel type is subjected to several test cycles using different spoke configurations to already ensure the correct balance is achieved during the construction phase. This technology was first used on their Formula 1 wheels and now BBS use this special machining operation to improve the performance of many road wheels like the LM-R, CI-R, CH-R, CHRII, CX-R and the ultra-exclusive forged aluminum FI and FI-R wheels.
BBS are certified to supply OEM manufacturers and conform to strict process controls and safety standards. BBS have routine audits to maintain compliance with the OEM’s, ISO and the German TUV.
FEA (finite element analysis) is an advanced computer simulation that helps determine and optimize the structure of each wheel. FEA data is continually improved through the actual destructive testing done in the lab. Using the most modern simulation technology, every BBS light alloy wheel is already tested during the construction phase to identify any possible weakness.
Before wheels go into full production, all new wheel types are subjected to numerous and rigorous testing. Impact tests along with cornering and rolling tests are all part of the process.
This test simulates the side pressure that is applied to the wheel when cornering. The wheel is secured to the table and an axle type shaft is bolted to the lug area. The wheel load, tire diameter and other factors are used to calculate a load force that is then applied to the shaft as it oscillates trying to find any weakness in the structure of the wheel. While the standard TUV test is 200,000 cycles, the typical BBS test run at BBS in Schiltach is 2,000,000 cycles.
With this special machine, BBS is able to simulate actual cornering loads, braking and acceleration forces in a real world situation. For example, using the Nürburgring or Hockenheim test, BBS can simulate the actual loads from these circuits testing their wheels to these extreme conditions.