Braking systems constitute a major component of ensuring safety while driving a vehicle. This mechanism enables you to manage and stop your vehicle to sidestep a potential crash or road accident. Two of the most popular braking systems used in modern vehicles are disc brakes and drum brakes. In this blog, we will explore disc brake vs drum brake, look at how each works, how they differ as well as their advantages and disadvantages; and finally conclude which is likely to be a consistent choice in terms of their performance and affordability.
Table of Contents
Drum brakes vs. disc brakes
What are drum brakes?
How does disc brake work?
What is a disc brake?
Differences between disc brake and drum brake
Advantages of disc brakes
Disadvantages of disc brakes
Advantages of drum brakes
Downsides of drum brakes
Takeaway: Drum brakes vs. disc brakes: which one is a Smart Choice?
Frequently asked questions
Drum Brakes vs. Disc Brakes
The operational design and mechanism of drum brakes and disc brakes are all that determine the fundamental difference between the two, making drum brakes pretty affordable compared to disc brakes. On the contrary, disc brakes are known for their greater braking performance; thanks to their advantaged advanced technological concepts. However, both of them come with their unique set of strengths and limitations. We will have a detailed insight into all these aspects.
What is a Drum Brake?
Drum brake is so termed due to its cylindrical design braking system fitted on all four wheels (used in the rare wheels in some modern cars. The main components of drum brakes consist of pistons, brake shoes, springs, and cylinder-shaped wheels. All these parts play their unique roles in seamless collaboration once the brake is pressed and released and rotates along with the moving wheel.
How Do Drum Brakes Work?
The working principle of drum brakes is as follows:
- Once you press the brake pedal, it activates the master cylinder, thereby creating hydraulic fluid pressure in the brake fluid.
- The brake fluid pressure is then passed through the brake pipes to each brake wheel cylinder.
- The wheel cylinder pressure works to push the pistons outwards.
- The outwards movement of the pistons forces the brake shoes to contact the inner peripheral surface of the brake drum.
- The friction generated between the brake shoes and the drum reduces the vehicle’s speed or brings it to a stop.
- Upon releasing the brake pedal, the pressure in the brake system decreases and the springs return the brake shoes from the drum to their initial position.
What is a Disc Brake?
A disc brake refers to a braking system that employs calipers to push a set of disc pads against its disc, also known as a “rotor,” to produce friction. Compared to drum brakes, the mechanism of disc brakes is fairly advanced and follows a relatively similar principle to effectively lower the rotational speed of the shaft, enabling individuals to gradually lessen the speed of the car or stop it instantly. The expression “disc brake” comes from the disc-shaped rotor to which all vital components of the mechanism remain affixed.
How Do Disc Brakes Work?
The working principle of drum brakes is as follows:
- Stepping on the brake pedal triggers the master cylinder of the brake system.
- The force on the piston of the master cylinder thereby passes pressure to hydraulic or brake fluid.
- The activated brake liquid, in turn, pushes the caliper pistons outward.
- As the pistons move outward, they force the brake pads against the rotating brake disc (or rotor).
- The contact between the rotor and the brake pads produces friction while decelerating the rotation of the wheel.
- Friction generates heat, though the resulting heat is transferred to the atmosphere through the surface of the rotor, not making it overheated.
- The compound effect of both friction and heat slows the moving vehicle to the chosen speed.
- In releasing the pressure in the brake pedal the hydraulic pressure decreases and the pistons of the caliper retract.
- The brake pads are released from the rotor, thus allowing the wheel to spin freely again.
Also Read: Complete Guide to Disc Brakes: Working, Components, And Benefits
Disc Brake Vs Drum Brake: Differences
Although disc and drum brakes perform their tasks based on the same principle, however, there is a notable difference in terms of their performance, efficiency, cost, and so on. Please go through the following table to recognize what are the key differences between these braking systems.
| Factors | Disc Brake | Drum Brake |
| Design | Exposed design with brake pads clamped onto the rotor. | Enclosed design with brake shoes fitted within the drum. |
| Braking Performance | Greater braking power, specifically at high speeds. | Although braking power is adequate, but less effective at higher speeds. |
| Heat Dissipation | Open design heightens the efficiency of heat dissipation | The enclosed design makes heat dissipation less effective |
| Exposure to Water and Dirt | Experience more exposure to wet climate and debris but less susceptive to moisture buildup due to ease of maintenance | The enfolded mechanism makes it less exposed to weather conditions but more vulnerable to moisture buildup. |
| Cooling | Superior cooling because of open design | The power of cooling is lacking due to the enclosed design |
| Maintenance | Maintenance, repair, and replacement are easy, although seem to be costly. | Maintenance, repair, and replacement are fairly challenging due to the enclosed design. However, maintenance costs tend to be low. |
| Brake Fade | Less vulnerable to brake fade. | More susceptive to brake fade |
| Stopping Distances | Shorter stopping distances | Longer stopping distance |
| Weight | Lighter option compared to drum brakes | Havier opposed to disc brakes |
| Noise | Can generate more noise while braking | Produce less noise when brake is applied |
| Corrosion | The rotor and caliper are more prone to corrode | Less susceptible to corrosion |
| Complexity of Design | Typically complex, making it more advanced and powerful | Simpler design with fewer components |
| Effect of Performance | Change in temperature does not impact performance | High temperature is likely to affect performance |
| Cost | Typically more expensive | In general more affordable |
Advantages of Disc Brakes
The following are the advantages of disc brake systems in cars:
Powerful yet compact: with a smarter and compact design disc brakes demonstrate a more powerful braking performance. The response time from brakes is fairly superior to drum brakes.
Greater heat dissipation: with an open design, its rotors, calipers as well as brake pads remain exposed to the air. This helps instant removal of heat, keeping the mechanism cool and making its performance consistent. New generation vehicles come fitted with ventilated discs, which are ideally superior at eradicating heat.
No corrosion: Unlike drum brakes, its brake components remain open rather than being enfolded in a chamber. This helps avoid clogging up of dirt. Also, due to easy accessibility, it becomes convenient to keep the disc clean lowering the possibility of rusting.
Safer than drum brakes: with ABS (Anti-Lock Braking System) modern disc brakes are quite safer compared to drum brakes.
Disadvantages of Disc Brakes
Following are some of the limitations of disc brakes in cars.
Expensive than drum brakes: The manufacturing cost of a disc brake is high compared to a drum brake setup. Hence, it also increases the overall price of a vehicle.
Maintenance of brake fluid: Noteworthy, changing the brake fluid at regular intervals is essential to avoid experiencing the consequence of poor braking performance.
Weight: Heavier compared to drum brakes, which is more likely to influence fuel efficiency in lighter models.
Noise: It can be noisier than a drum brake in certain conditions.
Also Read: Secure Your Drive: Check Now the Importance of Brake Pads
Advantages of Drum Brakes
Here are the advantages of drum brakes in cars.
Cost-effective: Given the manufacturing cost of drum brakes is lesser owing to its simple construction, installation of drum brakes is a cost-effective option for car buyers.
Can perform better in certain conditions: Disc brakes can operate much better in certain conditions like low-speed driving in city areas or wet conditions since they can expel water quickly
Compact Design: The design helps take up much less space, which means it allows for a more compact assembly.
Self-Adjusting: Some designs of drum brakes have self-adjusting features to prevent wear, thereby offering consistency.
Disadvantages of Drum Brakes
Following are the limitations of drum brakes
Overheating: Typically performs poorly when it comes to getting rid of the heat, leading to quicker brake fade under heavy usage.
Complexity: With multiple components, they are more susceptible to component failures.
Maintenance: Not only require more maintenance but it becomes complex due to its enclosed design.
Less Stopping Power: Compared to advanced disc brakes, drum brakes provide less stopping power, especially under high-performance conditions or at high speed.
Rusting: Due to the enclosed design, especially the metal components like pistons, springs, etc more likely to clog up with dirt, leading to rusting.
Also Read: 2WD vs 4WD: Which is Better for Your Driving Style?
Takeaway: Drum Brakes vs. Disc Brakes: Which is a Smart Choice?
From the above discussion, you can understand none of the disc or drum brakes are perfect and they come with their own set of pros and cons. This is the reason, it is prudent to look for cars or bikes available with a blend of disc brakes, typically at the front, and drum brakes at the rear, making it a seamless braking solution.
Noteworthy, most modern cars sold in India are equipped with a unique combination of disc brakes at the front wheels and drum brakes at the rear wheel. The design has become popular since it provides a seamless balance of performance and affordability.
Simply put, this setup enables you to make the best use of the disc brake at the front wheels as they need to deal with a significant portion—60% to 90%—of your vehicle’s stopping power. On the other hand, using drum brakes in the rear is a smart option, given they are relatively more economical and equally ensure safe performance. Moreover, having disc brakes at the front and drum brakes at the rear helps users leverage all their unique advantages which counterbalance their drawbacks.
Importantly, with the automotive technological evolvements, many leading car manufacturers such as Toyota, Hyundai, Honda, and Suzuki are shifting to offer all disc brake systems alongside anti-locking braking systems (ABS) to cater demand of customers on the lookout for the utmost safety and performance on the road.
Frequently Asked Questions
Q1. What is the similarity of brake pads and brake shoes?
Both brake pads and brake shoes are used as friction-generating materials for disc brakes and drum brakes respectively that press against the moving surface of the rotor or the drum to produce needed friction, enabling the driver to decelerate or stop a vehicle.
Q2. What is the tentative lifetime of drum brakes?
High-quality drum brakes are engineered to be operable for more than 1,00,000 km while the longevity of shoes is around 35,000 km. However, the driving conditions, a driver’s driving habits, and various other factors could impact the longevity of drum brakes.
Q3. What are the three types of disc brakes?
Three common types of disc brakes include Wave-type disc brakes, Drilled disc brakes, and Slotted disc brakes.
Q4. Why the maintenance cost of disc brakes is high?
Compared to drum brakes, the cost of maintenance of disc brakes seems to be expensive since they need more frequent and laborious maintenance.
Q5. What type of braking system is ideal for passenger cars?
A combination of disc brakes for front wheels and drum brakes for rear wheels is ideal for getting steady performance and efficiency at high speeds while staying within the budget.
Q6. What is brake fade?
Brake fade takes place under circumstances when the components of the braking system can no longer generate the needed friction enabling you to stop your car within a desired distance or standard time. The key cause that leads to brake fade is due to buildup of heat in the braking mechanism especially when the brakes are applied consistently at a high speed or with a heavy load.
Q7. Which brakes wear faster?
Ans. In general, the front brake pads wear out quicker as opposed to the rear ones since they are required to cope with more weight. However, if your car is used for carrying heavy loads at the back regularly, you will experience the reverse scenario – which means the rear brake will wear off faster.
