Leading Shoe
The brake shoe in a drum brake which gains some servo force from the rotation of the drum, increasing the braking effect. In the direction of rotation, its operating end "leads" and the pivoted end "trails". On rear wheel brakes there is one trailing shoe and one leading shoe to give adequate braking in both directions, especially when the handbrake is used. Front wheel drum brakes, with few notable exceptions, have twin leading shoes to give maximum effect in forward motion.