Bremskraft

Bremskraft, or braking force, is the force that opposes the motion of a vehicle when its braking system is applied. It is the external force transmitted to the wheels to reduce speed or bring the vehicle to a stop, and it can be expressed as the force at the wheel-ground contact or as the deceleration of the vehicle mass.

In most road vehicles, braking force arises mainly from friction between brake components (such as pads or shoes) and the wheel or rotor, converting kinetic energy into heat. The maximum achievable braking force on level ground is limited by tire–road friction: F_b,max ≈ μ N = μ m g, where μ is the friction coefficient, N is the normal load, m is mass, and g is gravity. The braking torque about the wheel axle is τ = F_b r, with r representing the effective brake or wheel radius.

Several factors affect Bremskraft. Road conditions (dry, wet, icy), tire condition and pressure, brake temperature, and weight distribution influence the available friction. Thermal fade can reduce braking effectiveness as brakes heat up. Modern vehicles may use ABS to optimize braking force by preventing wheel lockup, and many hybrids or electric vehicles employ regenerative braking to recover part of the energy while maintaining usable braking force.

Measurement and performance considerations include braking distance, deceleration (a = F_b / m), and braking efficiency. Safety standards specify minimum deceleration or stopping distance under various conditions. In addition to conventional friction brakes, rail systems and aircraft use supplementary methods such as magnetic or aerodynamic braking to enhance or modulate Bremskraft.

Bremskraft is thus a central parameter in vehicle dynamics, influenced by material properties, system design, and operating conditions, and it governs how quickly a moving body can be brought to a stop.