Why Do Most Vehicles Have Disc Brakes Only At The Front — Physics Explained

The law of inertia/Newton's first law states that an object in motion tends to remain in motion until and unless an external force acts upon it.

Think of your car or bike as that object in motion, and the brakes being applied is the external force brought into action! But brakes being applied leads to the shift of weight in the vehicle. The load that was equally distributed between the front and rear axles now exerts most of the pressure on the front axle.

When this shift in weight happens, the front end of the car or motorcycle dips as the suspension compresses. This ultimately results in increased grip levels at the front of the vehicle and decreased grip levels at the rear.

These principles of physics are common across all cars and motorcycles, whether it be the regular vehicles used for daily commute, or those used in motorsport. Hence manufacturers naturally choose to install more powerful brakes up front than at the rear.

Disc brakes are more powerful and much more effective than drum brakes. This is mainly due to the fact that disc brakes primarily rely on hydraulic pressure for their working, while drum brakes primarily rely on mechanical strength.

Disc brakes also cool down faster, and better heat dissipation characteristics help it retain its effectiveness for a longer period of time even. This is the reason one cannot find brake fade on disc brakes as much as on drum brakes.

Even those vehicles having brakes at both ends will have more powerful discs at the front and lesser ones at the rear.

DriveSpark Thinks!

Physics has a huge part to play in everything we do in our daily lives. Disc brakes at the front end is something that people look at from the design point of view more often than from the mechanical point of view. Well, the better the brakes at the front, the safer the riders/drivers are.