Wheelset development at AC Schnitzer A few definitions in advance Wheel/complete wheel = rim incl. tyre Wheel set = 4 wheels xi/xd wheel sets = special wheel sets for all-wheel drive vehicles (xDrive) Mixed-sized tyres = tyres wider on the rear axle than on the front axle All-round tyres = same tyre size on the front and the rear axle The wheels have a really important role: they are the postcard-sized connection between the vehicle and the road. They play a key role in the driving and propulsion as well as the deceleration - i.e. braking - of your vehicle. This gives the wheels a key role. Anyone who develops and sells wheels therefore has a great responsibility. We are aware of this responsibility; we have internalized it and implement it with every new development. AC Schnitzer only uses high-quality brand tyres, which are developed in close cooperation with premium tyre manufacturers. On the one hand, the tyres have to transfer the power of the engine perfectly to the road, on the other hand, properties such as braking behaviour, lateral control, water drainage in rain and the properties in straight running are important decision criteria for or against a tyre. A wheel set with wide base tyres is always also an investment in increasing driving safety and dynamics. In order to maintain driving comfort when using larger wheel dimensions, we at AC Schnitzer have actively opted against run-flat tyres and for sporty, conventional tyres. Conventional tires build up less rolling resistance and offer noticeably more comfort. AC Schnitzer specialises in mixed-sized tyres, i.e. wheel sets in which the wheels of the rear axle are wider than those of the front axle. This makes sense in terms of driving dynamics, as it allows strong drive forces to be transmitted while at the same time enabling high steering precision. Although the wider a tyre is, the more power you can put on the road, the rolling resistance caused by the tyre must not become too high. As the rolling resistance increases the wider a tyre is, AC Schnitzer works out the wheel dimensions that are balanced. AC Schnitzer develops special wheel/tyre combinations for all-wheel drive vehicles and orientates itself on the specifications of the vehicle manufacturer. These AC Schnitzer wheel sets are marked "xi/xd". Only those wheel dimensions are developed and approved for all-wheel drive vehicles that are as gentle on transfer cases as standard wheel sets. All AC Schnitzer wheel sets are tuned in multi-stage driving tests in traffic and on race tracks. Only after successful test runs the wheels are released for sale. All AC Schnitzer wheel sets are delivered fully assembled and balanced. They are subject to a two-year manufacturer's warranty. The scope of delivery includes mounting materials such as adapters and wheel bolts as well as the homologation certificate (with the exception of marked wheelsets for export). Philosophy/Design Generation change for AC Schnitzer rims If light alloy wheels consist of more than one component, they are referred to as multi-piece light alloy wheels. Three-piece AC Schnitzer alloy wheels consist of two rim halves and the wheel star. Not only is the name new, but also the design - both point to a generational shift in the wheel segment at AC Schnitzer. Although the AC1 rims are a new design, in one important aspect they pay tribute to their heritage: they too will certainly become a design classic. With the new AC1 rims, AC Schnitzer has reinterpreted the classic twin-spoke design. The result is a sporting hybrid look. In a sophisticated style, triangle tips taper towards the rim edge and widen towards the centre, separated by five trapezoids. These draw the eye directly to the unique classic element of the AC1 rim: the pentagonal hub cap with AC Schnitzer logo. Despite this multiplicity of styling elements, the design appears clean and masculine thanks to the very straight lines. The interplay of all these elements gives the AC1 wheel solidity and size. Especially in motion, the BiColor finish creates a strongly alternating effect. What is your personal benefit? - three-piece with visible bolting - high load capacity thanks to special construction - outer bed: forged, milled, rolled and clear lacquered - inner star: forged and milled - inner bed: aluminium block milled, rolled and anodized - weight-optimized racing rims with machined original AC Schnitzer logo - weight reduced thanks to forging, compared with conventional cast wheels - reduction in unsprung mass and gyroscopic forces on the car - improved driving dynamics. - open 5-spoke design in Black, giving a clear view to the brakes - corrosion-protected with high quality clear lacquer, guaranteeing a long life - technical development stage of AC1 rims Material Inner star: Forged block of high-strength aluminium Outer bed: High-strength aluminium Inner bed: high-strength aluminium Manufacture Steps on the way to perfection Inner star forged Outer bed deep-drawn, CNC-machined, high-gloss polished and clear lacquered Inner bed deep-drawn, CNC-machined, anodized The individual components are connected to each other with high-strength titanium screws. Surface Black – outer bed surface In this process, the wheel is first primed, then completely painted. A two-layer clear coat is then applied, consisting of a polyester primer and the matt acrylic clear coat. Inner bed / Surface In this process the inner bed is anodized Test Procedures / Safety After their design, the first sample rims are manufactured under real production conditions. These must undergo a multitude of tests. Among other things, the strength is tested. The "rim life" is simulated in the bending circumferential test. Every AC Schnitzer rim must withstand this intact in order to be allowed to be produced and sold at all. This is followed by vehicle-specific tests, including test installations with check of unobstructed movement and driving tests on public roads and on race tracks. Only after these procedures our rims receive their homologation, i.e. the approval to be used in road traffic. Wheels are safety-relevant components. Therefore, they are checked and tested with the greatest care. This starts with the first chemical material tests and ends with hard testing machine endurance runs: - § 30 StVZO wheel guideline - ECE R124 - Bending-rotation tests - 90° impact test - unwinding tests Scope of delivery - 4 complete wheels: AC Schnitzer AC1 Racing Forged Wheel Black with premium tyres - vehicle and rim-specific mounting and fastening material - pentagonal hub cover with AC Schnitzer logo - quality tag - certificate of authenticity - care instructions - homologation certificate Uniqueness of the wheel set with AC1 Racing Forged Wheels: - Developed exclusively for BMW vehicles - Specially developed for vehicles with high axle and wheel loads - With exclusive AC Schnitzer and “Geschmiedet” lettering - lightweight inner star by forging technology - open design in Black, giving a clear ect view of the brakes - Compatible with standard RDC system - Rim also available separately - 2 years warranty - Developed exclusively for BMW vehicles - Production monitored according to ISO standard - KDS mount for wheel alignment according to BMW specification is available