Ungefedert

Ungefedert is a term used in vehicle dynamics to describe parts of a vehicle that are not supported by the suspension springs. In this context, the unsprung mass comprises every component that moves directly with the wheel and is not cushioned by the springs, such as wheels, tires, brake assemblies, hubs, axles, steering knuckles, and related linkages.

The concept applies across modes of transport, including cars, motorcycles, and bicycles. In bicycles, for example, the wheel and tire are unsprung, while the fork and rear suspension are the sprung portion of the system. The exact composition of unsprung mass can vary with design and drivetrain, but it generally includes all elements that respond immediately to road irregularities.

The amount of unsprung mass has a direct influence on ride quality and handling. A higher unsprung mass makes it harder for the suspension to keep the tire in contact with the road over bumps, increasing ride harshness and reducing traction. It can also affect braking stability and steering feel. Conversely, reducing unsprung mass tends to improve the suspension’s ability to follow the road, resulting in smoother ride and better grip, albeit with potential trade-offs in durability, cost, or structural strength.

In practice, engineers strive to minimize unsprung mass through lighter wheels, brakes, and components while maintaining safety and stiffness. The term ungefedert is commonly used in German automotive and mechanical engineering literature to discuss suspension design and vehicle dynamics, particularly in the context of ride comfort and road-holding performance.