Why are ventilated discs not used for rear wheels?
2 Answers
Reasons why rear wheels do not use ventilated discs: The braking force of the rear wheels is smaller, and the heat generated is less compared to the front wheels. The brake disc is a crucial component in the braking system, which can be categorized into disc brakes, drum brakes, and air brakes. Structurally, they are divided into solid brake discs and ventilated discs, while material-wise, they include carbon fiber ceramic brake discs and metal brake discs. Methods for maintaining brake discs include: 1. Developing good driving habits; 2. Avoiding emergency braking; 3. Regularly inspecting brake pads and discs; 4. Checking the thickness of the friction pads; 5. Having professionals inspect the brake shoes; 6. Using original equipment manufacturer (OEM) brake pads and discs for replacements.
After driving for so many years, I've noticed that rear brake discs usually don't use ventilated designs like the front ones, primarily due to braking force distribution. During braking, the vehicle's center of gravity shifts forward, causing the front wheels to bear about 70% of the friction, generating significant heat that requires ventilated discs for rapid cooling to prevent overheating and failure. The rear wheels only handle the remaining 30% or so, producing much less heat that a solid disc can easily manage, while also being simpler and more durable. This relates to the car's overall weight distribution and inertia, with the engine's forward position increasing the front wheels' burden. Adding ventilated discs to the rear wheels would only introduce unnecessary weight and cost without any benefit for everyday driving. Some high-performance vehicles, like sports cars, might use ventilated discs all around to enhance cooling, but regular cars don't need this complexity. Maintenance is also easier with solid rear discs, reducing long-term costs. In short, this is a smart engineering design to balance performance and cost, ensuring both safety and economy.
