Huge disc brakes on an Aston Martin V8 Vantage
Take a look at the brakes on your car: they are most likely to all be disc brakes.
However, it wasn’t too long ago that cars had drum brakes both front and rear.
In fact, several modern cars still retain drum brakes, albeit only on the rear wheels.
Why the change? Why are disc brakes better than drum brakes?
How do brakes work?
Simply put, enough friction and heat will stop a moving car.
In the case of disc brakes, when you apply resistance to a spinning rotor via a set of calipers, that slows the car down.
On drum brakes, a set of “shoes” inside a drum are forced against the drum’s walls when the brake pedal is pressed, slowing the car down.
Drum brakes
The effectiveness of brakes partially depends on their ability to absorb and dissipate heat as quickly as possible.
Several other areas also affect braking effectiveness: vehicle weight, braking force and total braking surface area.
That’s why racing and high performance cars like Lamborghinis and Porsches have massive, manhole-sized discs, while your Honda Jazz has what look like bottle caps for brakes.
It’s all relative to the size of the vehicle and its intended purpose.
Disc brakes are today usually made out of steel but can also be made out of more exotic materials like silicon carbide and carbon-ceramic for high-performance cars.
Carbon-ceramic disc brakes made by automotive parts manufacturer Brembo.
They are usually ventilated, with more expensive ones having holes drilled into them for superior cooling.
Major disc brake manufacturers include Brembo, AP Racing or StopTech.
Disc brakes vs drum brakes: the benefits
Drum brakes were common on cars up until the 80s, where the easing cost and improved performance of disc brakes made them impossible to ignore.
Here are more advantages of discs:
- They take up less space within the wheel, with a slimmer design and fewer components
- The brake assembly is fully exposed to the air, allowing for better cooling compared to drums, which have all components housed internally.
- Maintenance is easier on discs than drums as you can take a look at the disc through the wheel and see if anything is wrong with the rotor.
- Disc brakes can be fitted with ABS and other advanced braking technologies compared with traditional mechanical drums.
- Braking with discs is relatively linear, improving passenger comfort.
- Braking performance with discs can be made more effective without too much hassle
However, drums have some advantages too. They are cheaper to manufacture and replace when they wear out, leading to lower running costs.
But in Singapore, we are already paying so much for our cars, so it makes sense to have the best braking technology.
Disc technology has also matured to a point where it simply pays to have them on your car without paying too much of a premium.
