What is the difference between drum brakes and disc brakes?

[JohnnyFitz]

1. Structural comparison: The principle of drum brakes is to add pistons inside the brake drum, which are pushed by hydraulic pressure to press against the brake drum, generating friction to achieve the braking effect. On the other hand, disc brakes apply hydraulic pressure to the caliper, causing the friction material to clamp the brake disc, thereby achieving the braking effect. 2. Principle comparison: The principle of drum brakes involves hydraulic pressure pushing the pistons, causing the brake shoes on both sides to press against the inner wall of the wheel, thus achieving the braking effect. Due to the forward motion of the wheel, the rolling force generated will react on the brake drum, amplifying the braking force, which affects ride comfort. In contrast, disc brakes use a hydraulic pump to push the brake caliper, thereby applying force to the brake pads to achieve the braking effect. Therefore, the braking force directly depends on the pressure of the brake caliper and is not amplified like drum brakes, resulting in inherently smaller braking force. 3. Advantage comparison: Drum brakes provide greater braking force, allowing for timely stopping in emergencies and effectively avoiding accidents. Due to the large inertia of heavy trucks, which require higher braking strength, drum brakes have an irreplaceable position in heavy trucks. Disc brakes, being an external braking system, offer good heat dissipation and easy control, allowing for high-frequency intermittent braking and integration with ABS intermittent braking.

[StBrady]

I've driven quite a few cars, from old classics to modern new ones, and experienced the differences between drum brakes and disc brakes. Drum brakes are hidden inside the wheel, shaped like a drum, and rely on internal shoes pressing against the drum surface to brake. They have a simple structure and low cost, which is why many budget cars still use them on the rear wheels. The downside is poor heat dissipation—after a few brakes on a steep slope or under heavy load, they overheat, and the braking force drops noticeably, making driving feel less secure. Disc brakes, on the other hand, are outside the wheel, shaped like a plate, and the caliper clamps directly onto it. They dissipate heat very well, making them especially safe at high speeds or during emergency braking, which is why modern cars prefer using them on the front wheels or all four wheels. Disc brakes respond quickly and perform reliably even in rainy conditions, though they are a bit more expensive. Having used both types, I find disc brakes more worry-free for daily driving—safety comes first, and the extra cost is worth it.

[MiguelMarie]

As someone who often repairs cars myself, I find that drum brakes and disc brakes differ significantly in maintenance. Drum brakes have a complex internal structure; you have to remove the wheel to clean or replace parts. They are prone to rust due to dust or water accumulation, making the process time-consuming and labor-intensive. The advantage is that the parts are cheap, but the brake shoes wear out quickly with frequent use, requiring regular checks. Disc brakes, on the other hand, are straightforward externally—replacing brake pads takes just minutes. The discs dissipate heat easily and are less likely to warp, offering better durability, though the parts are more expensive. In changing weather conditions, disc brakes have superior drainage, making them more reliable during rainy seasons. Drum brakes are commonly used on the rear wheels of trucks, suitable for heavy loads but not frequent braking. From an overall maintenance perspective, disc brakes are more hassle-free, especially for city commuting—choosing them is the right call.

[DiGenesis]

From a driving experience perspective, disc brakes undoubtedly win in terms of performance. I've test-driven various models, and disc brakes offer direct response, shorter braking distances, no drifting during high-speed cornering and hard braking, with almost zero heat fade. Drum brakes, on the other hand, are weaker, with slower braking force and potential failure during continuous downhill driving. In rainy or snowy conditions, disc brakes drain water quickly and provide stable braking, while drum brakes are prone to slipping on wet surfaces. Comfort-wise, disc brakes operate quietly and offer flexible handling, whereas drum brakes produce a humming noise during heavy braking. Although drum brakes on the rear wheels are cost-effective and require less maintenance, when it comes to prioritizing performance, disc brakes are the undeniable choice.

[DiPenelope]

Reflecting on decades of driving experience, most early cars used drum brakes, which were cheap to repair but had many issues—prone to rusting in rainy weather and a headache to maintain. Modern cars have fully upgraded to disc brakes, offering leaps in heat dissipation, efficiency, and safety, making driving much easier. Disc brakes have a simple structure and respond quickly, while drum brakes have multiple internal friction surfaces that wear out easily. On slippery rainy roads, disc brakes perform better with their drainage holes to expel rainwater, whereas drum brakes require more frequent inspections and maintenance to prevent failures. Nowadays, most family cars opt for disc brakes, significantly improving overall safety. As an experienced driver, I recommend paying attention to updates in the braking system.

[DeEmily]

In daily commuting, the difference between drum brakes and disc brakes significantly impacts driving. Drum brakes are typically lower in cost and commonly found in the rear wheels of ordinary cars; however, in stop-and-go city traffic, their braking response is slightly slower, and effectiveness decreases when heated, especially in summer. Disc brakes provide immediate braking, offer stable grip on wet roads, and are simpler to maintain, despite their higher initial cost. From a comfort perspective, disc brakes produce less noise; drum brakes tend to develop unusual sounds over time. For practical considerations, disc brakes offer more peace of mind for everyday vehicles; heavy-duty vehicles like trucks often use drum brakes to save costs, but require frequent checks to ensure safety.