Drum brakes and disc brakes: which is better?

Essential for safety and vehicle control, the braking system is one of the most important components of a car. It's thanks to this system that you can anticipate slowdowns on the road or stop your vehicle if necessary. In recent years, braking systems have been perfected and developed thanks to advances in the automotive industry. Today, the two most common braking systems are drum and disc brakes. These play a key role in the safety of your vehicle.

Decades ago, drum brakes were commonplace in the automotive industry. Today, however, disc brakes seem to be taking over. Discover the key differences between disc and drum brakes. Here's an overview.

Drum Brakes

Simple friction brakes, drum brakes consist of a type of bell called a "drum. Inside the drum are two brake shoes that press against the drum from the inside when braking, as well as a piston and springs. Drum brakes are slightly less powerful and therefore more suitable for rear wheels.

Advantages of drum brakes

Drum brakes are simple friction brakes. The drum is easily identifiable and simply a large wheel hub. The drum on a car is similar, but less visible because the rims are mounted on the hub. Inside the drum are two brake shoes with a lining. When braking, these two brake shoes press against the drum from the inside. On motorcycles and vintage cars, this is usually done mechanically with a cable, while newer models are hydraulically operated.

• The advantages of drum brakes include the use of low actuation forces. The effectiveness of drum brakes is based on the principle of self-reinforcement: as the wheel rests on the brake shoes, the rotational forces are absorbed by the components that make up the braking system. So with drum brakes, drivers don't have to press down hard on the brake pedal to slow or stop their vehicle.
• They are also significantly less expensive than disc brakes.
• Drum brakes have one significant advantage: they are protected from the elements. The presence of mud or shiny water does not affect the performance of this type of braking system.
• What's more, the abrasive particles generated by repeated braking don't build up on the rims.

Disadvantages of drum brakes

• The performance of this system is slightly lower than that of disk brakes, which is why it is mainly used on the rear wheels of cars. Over time, we have realized that this type of brake is not resistant to overheating and that there is a risk of wheel lockup, which can be dangerous when driving your vehicle.
• One of the disadvantages of this system is the relatively complex replacement of the brake shoes, which requires opening the drum.
• If the brake shoes are not evenly applied, braking performance will be uneven. The typical result is that the car skids during braking.
• Drum brakes are also susceptible to wear because heat is relatively difficult to dissipate. The result is a reduction in braking power during successive braking operations. A few decades ago, it was common practice to take a break downhill to allow the brakes to cool.

Disc Brakes

Disc brakes are designed for the front wheels because they are the main source of braking. Disc brakes are made up of a steel or ceramic disc, a caliper, and brake pads that are housed in the caliper, the part that wears out the fastest because when you brake with a vehicle equipped with disc brakes, it is this famous caliper that comes into action to compress the pads against the disc and activate the brakes. Technically, when you brake, the pads "pinch" the disc to slow the vehicle.

Advantages of disc brakes

This type of brake system is used on most vehicles. It is valued for its longer life, the quality and power of the braking it provides, and its greater safety.

Disc brakes are also relatively simple in design. The brake disk, made of steel or ceramic, is mounted on the wheel hub. A caliper holds the pads. The pads press against the disc like pliers, providing high deceleration. Disc brakes on passenger cars are usually hydraulically operated. Pistons extend from the calipers during braking. On heavy trucks, however, these pistons are actuated pneumatically, by compressed air.

• Ventilated disc brakes are special. The disc is hollow on the inside to facilitate heat dissipation.
• A disc brake has excellent braking performance and provides smooth braking, especially compared to drum brakes.
• The slightly higher actuation force is compensated by a brake booster.
• Fading and uneven braking are unknown phenomena with disc brakes.

Disadvantages of disc brakes

• This braking system also has its disadvantages. In very wet conditions, deceleration can be significantly lower during initial braking.
• In addition, the hydraulic braking system is not particularly fragile but requires more maintenance. Maintenance is required. Brake fluid should be changed, usually every two years.
• The brake pistons can become stuck in the caliper. In this case, service is required. The same goes for leaks or replacing a brake hose that has become permeable.
• Disk brake maintenance is also a bit more expensive. Sooner or later, you will need to replace not only the pads but also the discs. But the advantages undoubtedly outweigh the disadvantages. As a result, disc brakes have become standard equipment.