What is the difference between floating brake discs and fixed brake discs?
3 Answers
Floating brake discs and fixed brake discs differ in the following aspects: 1. Braking mechanism: Floating brake discs slide freely along the axle pins that match the bracket. When the piston extends and the inner brake pad contacts the brake disc, the brake caliper floats inward, causing the outer brake pad to also contact the brake disc, thereby generating braking torque. Fixed brake discs generate friction and braking torque when the piston inside the brake caliper extends the brake pad to clamp the brake disc. 2. Construction: The brake caliper of a floating brake disc is floating, whereas the brake caliper of a fixed brake disc is fixed. 3. Size: Floating brake discs do not need to span the brake disc, so their axial and radial dimensions are smaller. Fixed brake discs have a more complex structure, requiring internal oil passages and external channel connections that span the brake disc, making their size relatively larger compared to floating brake discs.
When I first got into cars, I was also curious about the difference between floating brake discs and fixed brake discs. Floating discs have a floating part that allows slight movement, reducing deformation and vibration caused by braking heat, making them suitable for high-speed or frequent braking scenarios, such as mountain driving or racing. Fixed discs are completely fixed, simpler, more reliable, and cheaper, commonly used in regular city commuter cars. Floating discs offer more precise and smoother braking but may be more expensive to maintain, with slightly more complicated inspection and replacement. Fixed discs, if not properly treated for thermal expansion, can easily produce noise or uneven heating. Overall, the choice depends on the vehicle type and usage needs—floating discs are more common in high-performance cars, while fixed discs are suitable for entry-level vehicles.
As an enthusiast who frequently modifies cars, the advantage of floating brake discs lies in their ability to freely expand and contract in response to heat, avoiding hot spots or brake judder, thereby enhancing stability during aggressive driving. Fixed discs have a rigid structure, offering simplicity and durability, but they are prone to generating noise and vibration during hard braking. Floating discs are commonly used in sports cars or on the track, offering weight reduction and high efficiency, while fixed discs are economical and practical, often found in family cars. After trying them, I found that floating discs provide more direct and sensitive braking feedback, especially when entering corners at high speeds. Additionally, the removable design of floating discs makes upgrades easier, whereas fixed discs are convenient for complete replacement but wear out faster, requiring regular checks to prevent safety issues.
