The alloy wheel has several technical functions:
- It is the connecting element between the vehicle's hub and the tire for which it must guarantee the prescribed inflation pressure.
- It is subject to stresses deriving from its own weight, from dynamics, from the transmission of traction and from vehicle braking.
- performs an important function of ventilation of the braking elements when placed on the hubs (that is, in modern vehicles and for requirements of limitation of the suspended masses, practically on all).
The design and testing of alloy wheels for motor vehicles, therefore, is an activity closely linked to the particular vehicle they are to equip. There is, first of all, a dimensional aspect linked both to the size of the tires and to the type of "fitment" (number and size of bolts/nuts for mounting, camber, diameter of the bore) foreseen by the specific vehicle.
There is also a structural aspect linked to the mass of the vehicle and its performance. The expected stresses in terms of support of the vehicle's own weight, resistance to loads deriving from dynamics (the more important the greater the performance, also in terms of vehicle speed), power to be transmitted and braking to be endured, are specific characteristics of each vehicle. Finally, the fluid-dynamic aspect is linked to the size and the power to be dissipated of the braking system (in turn, sized according to the performance of the specific vehicle).