What does 'four pistons in the front and two in the rear' mean?
1 Answers
'Four pistons in the front and two in the rear' refers to the number of pistons in the brake calipers. 'Four in the front' means the front wheels use calipers with four pistons, while 'two in the rear' indicates the rear wheels use calipers with two pistons. Since most of the braking force is handled by the front wheels, the front wheels require much greater braking force than the rear wheels. Therefore, the front wheels use four-piston calipers, while the rear wheels only need two-piston calipers. In theory, the more pistons a brake caliper has, the greater the braking force it can generate. However, it's essential to consider whether the brake master cylinder's output volume matches. Otherwise, adding more pistons would be superfluous. Even with sufficient output volume, excessively strong braking force could easily lead to wheel lock-up. How to identify the number of pistons: The number of pistons can be distinguished by appearance. There are several circular protrusions on the caliper, and these protrusions are the pistons. The pistons in the caliper are symmetrically arranged on both sides, which not only increases braking force but also ensures even distribution. When counting the pistons, you only need to count one side (due to symmetry), and the total number of pistons is the number of protrusions multiplied by two.
