bakhjulssko

Bakhjulssko is a brake component used in drum brake assemblies on the rear wheel of a vehicle. It refers to the brake shoe or shoes that, when actuated, press friction material against the inner surface of a rotating brake drum to slow or stop wheel rotation. In a typical drum brake, each rear wheel may use one or two shoes, arranged as leading or trailing shoes depending on the design, to achieve effective braking and self-energizing effects.

Construction and operation: A bakhjulssko consists of a curved metal backing plate with attached friction material. When hydraulic or mechanical actuation applies the brake, wheel cylinders push the shoes outward against the drum, aided by return springs. An adjuster sets the nominal distance between shoes and drum. Many vehicles place the parking or emergency brake on the rear drum brakes, using the shoes as the working elements of the parking mechanism.

Materials and variants: Friction linings are designed to withstand heat and wear, with modern formulations avoiding asbestos and using non-asbestos composites. Drum brake systems vary in complexity, but the basic principle remains: shoes convert kinetic energy into heat through friction.

Applications and maintenance: Rear drum brakes with bakhjulssko have been common on many older and some modern vehicles, particularly where compact packaging or a parking brake is needed. Regular inspection is advised to check lining thickness, shoe wear, and for contamination by oil or grease. Replacement is performed when the friction material reaches the minimum thickness specified by the manufacturer, and all related hardware—springs, adjusters, and wheel cylinders—should be inspected for proper function.

Etymology: The term bakhjulssko is used in Scandinavian languages, translating roughly to “rear wheel shoe.” It describes the rear-wheel brake shoe in drum brake systems.