BBS CH-R 2 Piece Flow Form Wheels 21X10.5" ET17

21 MIN

Melting

The AlSi7Mg alloy is melted down in the melting furnace at approx. 1000°C. Before being transported to the casting machines, the alloy is cleaned and purified again using a melt cleaning process.

The low-pressure casting process with its controlled and careful cooling process, tailored for every wheel, ensures a perfect microstructure for the wheel blank. The BBS Flow Forming wheels are cast as a compact blank, which is then elongated in the subsequent Flow Forming process. All BBS Flow Forming casting blanks are only cast in the BBS main factory in the Black Forest.

Every blank is X-ray inspected and checked for pores and inclusions. This ensures that the high BBS quality requirements for the microstructure of the material are met. Distortion measurement ensures that the high BBS quality requirements for the blank are met.

24 MIN

Pre-processing
Mechanical pre-processing to ensure that the wheel is perfectly prepared for the elongation process.

Heating
So that the blank is able to withstand the extreme loading during the Flow Forming process it is heated up to allow the microstructure to become more formable.

Flow Forming
Three rotating rollers elongate the wheel blank to the desired rim width with more than 10t of pressure via a custom wheel matrix. This rolling process specifically models the blank and strongly compresses the material in the rim well. This leads to a huge improvement in the mechanical properties of the material, while significantly reducing the weight compared with a cast wheel. The flow-forming technology allows a rim well thickness of just 2.25 mm on the finished wheel (inc. lacquer) to be achieved.

14 HRS 840 MIN

Solution annealing
Repeated strong heating, so-called solution annealing of the blanks, dissolves sufficient alloying elements in the molecular solid solution, allowing them to adopt a closer connection.

Quenching
Rapid quenching cools the blanks to 70°C and hardens the molecular structure. This reinforces the close bonds, but makes the wheel blank brittle at the same time.

Artificial ageing
Subsequent artificial ageing allows the blank to rest at an exactly defined temperature and the solidified microstructure is able to relax once more. The high-precision interplay between temperature and time for the artificial ageing equips the wheel blank with the exact desired strength values and therefore the unique BBS material quality

25 MIN

CNC machining inc. weight optimization
Highly-modern CNC machines finish the inside and outside of the wheel blank to the final dimensions. As well as drilling spherical section, wheel hub and valve hole, the wheel connection is also turned to the final size. The flow forming wheels from BBS also undergo special mechanical machining for weight optimization. Material which is not relevant to the strength is milled out at the wheel connection and in the sections between the spokes, thereby significantly reducing the rotating mass of the wheel. This special machining takes more than twice the time compared with a normal BBS low-pressure cast wheel. With this optimization, for 19 BBS Flow Forming wheels, a weight of 10.8 kg is achieved (CI-R 19).

Quality inspection runout
Every wheel must go through the runout check. Only if the runout check is passed according to the extremely stringent BBS tolerances is the wheel allowed to enter the rest of the manufacturing process.

Finishing
In the first stage of finishing the complete blank is deburred within an automated process, removing remaining protrusions, as well as sharp edges. The second step during finishing is manual fine grinding. The surface and edges are prepared perfectly for lacquering and further surface finishing.

Quality inspection sealing
All wheels are subjected to internal helium gas leak testing. The wheel is sealed with a hood and helium injected into the well. Only if the sensors in the center of the wheel do not detect any helium molecules is the wheel then permitted to enter the surface finishing area in the Herbolzheim factory.

4.75 HRS 285 MIN

Pre-treatment
Comprehensive cleaning in the pre-treatment area removes all contamination on the wheel surface, which could potentially affect later lacquer application on the wheel. This also includes the tiniest grease residues from human contact, which would be visible on the flawless surface later on.

Base powder application
Application of the matching base powder for the subsequent colored paint of the wheel. The base powder ensures a smooth and sealed surface, on which even the finest colored paint can be applied later in the process. A gentle drying process ensures that the base powder is cured and the wheel is ready for color painting.

Application of colored paint
Application of the colored paint onto the powder-coated wheel via electrostatic coating and compressed air spraying. This ensures even paint distribution even in difficult places, giving a perfect paint coating.

Laser engraving
Wheel features and lettering are lasered in three dimensions into the wheel surface. The ultra-precise control allows the focal distance of the laser to be specified down to individual paint layers. Due to their spatial arrangement, lasered elements have an extremely high-quality appearance.

Clear lacquer application
The final clear lacquer coat seals the wheel and gives it its unique appearance. Depending on the version, a satin or gloss clear lacquer are applied. The clear lacquer also provides protection against weathering and minor stone impact.

Final manual quality control final check of the surface quality by a staff member to ensure compliance with the high BBS quality standards. The wheel then goes to be packed & assembled.

1 MIN

Assembly of stainless steel collision protection
The stainless steel collision protection is placed on the wheel and automatically attached. It protects the wheel during collisions with the curb and can be replaced.