Disc vs drum brakes: What is the difference? [with PDF]
There is a high probability that the vehicle you own might be equipped with either a disc or drum brake. If you ever wondered what is the difference between disc and drum brakes? If yes, then you have come to the right place, my friend.
Today at The Mechanical post we’ll discuss the differences between the disc and drum brakes that set them apart.
Get your Free copy of the PDF on the difference between disc and drum brakes at the end of the article.
What is a Drum brake?
The drum brake is a type of brake that makes use of a set of brake shoes placed inside of a cylindrical drum and when engaged they rub against the inner part of the drum and hence stop the vehicle with the help of frictional force.
What is a Disc brake?
The disc brake gets its name because of the slim disc used in this brake. A slim metal disc is connected to the wheel axle. As the wheels rotate, the disc also rotates with it. At one part of the disc is a small clamping device called the brake caliper. When the brake pedal is pressed, the brake pads present in the calipers rub against the disc and thereby cause the vehicle to stop with the help of friction.
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Difference between Drum and Disc brakes
| Drum Brake | Disc Brake |
|---|---|
The Drum brake is placed inside a cylindrical drum and when engaged the brake shoes internally expand to rub against the inner surface of the drum and thus cause the vehicle to come to a halt. | The Disc brake is a metal rotor that rotates with the wheel and has a caliper at one part of the disc. When engaged, the brake shoes of the caliper are pressed against the disc which cause the vehicle to come to a halt. |
| The response time of drum brakes is slower. | Disc brakes have a faster response time and hence the vehicle comes to halt faster. |
| The stopping distance of vehicles with drum brakes is more. | Vehicles with Disc brakes require less distance to come to a halt. |
Drum brakes are self-locking. | Disc brakes do not self-lock. |
| Drum brakes are comparatively heavier in weight than disc brakes. | Disc brakes are lighter in weight. |
The friction pads of drum brakes are subjected to uneven wear due to their curved shape. | As disc brakes use flat friction pads, hence uniform wear of friction pads takes place. |
| The heat dissipation in drum brakes is poor as the whole assembly of the drum brake is enclosed in the drum. | On the other hand, the heat dissipation of disc brakes is very good as it is open to air as well as the disc has cutouts in it that help in improved airflow and heat dissipation. |
| Due to slower heat dissipation, the braking performance of drum brakes is greatly reduced at high temperatures. | Faster heat dissipation enables the disc brakes to operate effectively even at high temperatures. |
| Drum brakes are cheaper when compared to Disc brakes. | Disc brakes are expensive than drum brakes and is a newer technology. |
In wet conditions, there are chances of water entering the drum, which may reduce the braking power of the brake. | Disc brakes are not affected in wet conditions like the drum brake and work effectively. |
Since, the drum brake is enclosed inside a drum, carrying out an inspection or reaching it for maintenance is a bit difficult and time consuming. | Disc brakes can be easily inspected as well as maintenance & repairs can be carried out easily. |
Drum brakes have comparatively lower torque transmitting capacity. | Disc brakes have higher torque transmitting capacity. |
| Drum brakes have been in the market for quite a long time and are used in older cars as well as in some modern cars along with disc brakes. | Disc brakes are comparatively newer and are being used in modern supercars, sedans, bikes, scooters etc. Also, more and more manufacturers are switching to disc brakes. |
That’s a brief on the Difference between Drum and Disc brakes. Do you know any more differences between the two? Let us know in the comments!
We’ll be back with an interesting article, till then Keep Learning!
