If you pay attention to vehicle brakes, you will notice that the size of the front disc is larger than the rear disc.
What makes the front brake bigger than the rear brake?
1. Increase braking power
When the vehicle is braking, there is a weight transfer which makes the front of the vehicle tend to move downward.
That is a weight transfer, this event occurs because the torque of the vehicle towards suddenly held by the brakes on the front wheels.
So that the weight of the vehicle will focus more on the front wheels.
That is why, the front wheel braking load is greater. So that the front brakes need to adapt.
To increase braking power, we can do several things. One of them increases the friction surface between the brake pads and the disc.
So, the size of the front brake pads is made bigger so that the friction surface is bigger. To do its job, the surface of the brake pads will rub against the disc. So the disc size must match the size of the brake pads.
Due to this adjustment, the disc size is larger than the rear brake.
2. Optimize brake cooling
To stop the vehicle, the brakes use friction between the brake pads and the disc. This process will generate heat, besides that, the front wheels are close to the engine, which is located in front.
So that the heat source in the front area of the vehicle is higher.
One of the way to cool the braking system is to widen the dish's contact with fresh air.
It will make the brake cooling process faster so that overheat do not occurs even the brakes used for a long time.
Overheat of the brakes causes the braking system failure. Brake pads that are exposed to heat continuously will harden. And that makes the friction force decrease, so the ability of the brake pads to stop the rotation of the disc is decreases.
3. Increase the braking moment
If compared to drum brakes, disc brakes are less than optimal to withstand high torque. The reason, the friction surface on the disc brake is narrower than the drum brake.
So that cars with large weights do not use disc brakes as a braking system.
But when the disc diameter is enlarged, it makes the braking moment stronger.
This means that disc brakes can be used to stop high torque rotation.
This is very useful when the car is move at high speed. The higher the speed of the car, the greater the torque produced. And to do a braking, disc brakes require a lot of effort.
The larger disc design allows the brakes to overcome this problem.