Difference Between Dual-Piston Calipers and Single-Piston Calipers?

[LeClayton]

The difference between dual-piston calipers and single-piston calipers lies in their design approaches. Here are the specific details: Single-piston calipers, commonly found in mass-market vehicles, typically feature a unidirectional piston configuration. The brake pad on the opposite side is pushed by the reaction force of the caliper, hence earning the name "floating caliper." In contrast, dual-piston calipers have both inner and outer sides fixed, with each side's brake pad clamping force managed by separate pistons, thus referred to as "fixed calipers." When comparing single-piston calipers to multi-piston calipers, single-piston designs often leave unused space that cannot be filled. To minimize the caliper body's size and maximize piston area, dual-piston calipers were developed. Most single/dual calipers on the market are floating calipers (also called unidirectional floating calipers). True multi-piston calipers, however, are fixed brake calipers (also known as fixed opposed-piston calipers). Floating brake calipers generally have brake pistons only on one side. When the piston presses the friction pad against the brake disc, only one side makes contact initially. As hydraulic pressure peaks, the piston can no longer extend outward, creating a reaction force that moves the entire caliper, bringing the opposite friction pad into contact with the disc. When both pads engage, full braking force is achieved. Thus, the floating caliper's key feature is its ability to shift laterally, ensuring both friction pads contribute to braking. Opposed-piston calipers, on the other hand, feature pistons on both sides that simultaneously push the friction pads against the brake disc to generate braking force. This design necessitates a fixed caliper position during operation.