Solid brake disc
A solid friction ring is joined to the brake disc chamber. This design can mainly be found on rear axles as well as on the front axle of low-powered vehicles.
Vented brake disc
The vented brake disc consists of two friction rings that are joined either on the outside (FIGURE 1) or the inside (FIGURE 2) to the brake disc chamber. It is mainly installed on the front axle but also on the rear axle of high-powered vehicles. The two friction ring halves are joined by pillars (FIGURE 3) or by vanes (FIGURE 4). The vanes can be arranged radially from the brake disc chamber to the outer edge of the brake disc (FIGURE 5) or can be formed in a turbine arrangement (FIGURE 6). It may be necessary to install the turbine arrangement in a specific position which may be identified by L or R. While driving, air circulates through the space between the friction ring halves, thus cooling the brake disc faster.
(FIGURE 1) OUTSIDE
(FIGURE 2) INSIDE
Drilled brake disc:
This is a vented brake disc which has additional axial holes through the friction ring surface towards the ventilation channel in the middle of the brake disc. These holes allow the water that collects on the friction ring during wet braking to flow off more effectively. This enables the brake to achieve its optimum efficiency faster during wet braking. The holes in the brake disc additionally minimise the effects of brake fading, as the gasses that are produced while braking escape through the holes. The holes however contribute to increased brake pad wear and may also result in loss of comfort compared to a solid brake disc. To maintain the braking effect, blocked holes must be cleared as part of servicing work.
Slotted brake disc:
Likewise, the slots allow water to flow off faster from the friction ring during wet braking, thus also enabling the brake to achieve its optimum efficiency faster. In the same way as the drilled version, increased brake pad wear must be taken into account.
Wave brake disc:
This design is characterised by its wavy outer edge. It mainly offers advantages in terms of appearance and is used on motorcycles and bicycles. The brake pads are also subject to increased wear.
Two-piece composite brake disc:
In this design, the brake disc chamber that is primarily made of aluminium, is joined to a friction ring made of cast iron. Both parts are mechanically joined by rivets or bolts with springs. The use of aluminium substantially reduces the weight of the brake disc which in turn contributes to reducing the unsprung mass. Connecting the friction ring with bolts and springs has a positive influence on the intrinsic vibration characteristics of the brake disc.