Fjæring

Fjæring is the system in a vehicle or equipment that suspends the chassis and absorbs vertical motion caused by irregularities in the surface. It serves to keep tires in contact with the ground, cushion impacts, and maintain ride comfort and handling characteristics under varying loads and speeds.

A typical fjæring system comprises springs, dampers, and related mounting hardware. The springs (fjærer) store energy from impacts. The dampers (dempere) convert kinetic energy to heat to control motion. Depending on design, fjæring can include coil springs, leaf springs, torsion bars, or air springs, often combined with anti-roll bars and bushings to control movement and maintain geometry.

Types and configurations vary. Passive fjæring uses fixed springs and dampers; semi-active systems adjust damping in response to driving conditions; active fjæring uses actuators and sensors to optimize ride and handling in real time. Common layouts include independent suspension (each wheel moves independently) and dependent suspension (solid axle). In automobiles, coilover setups, MacPherson struts, double wishbone, and leaf springs are examples; air suspension provides variable ride height and spring rate.

Applications extend beyond cars to motorcycles, trucks, buses, and some bicycles. Maintenance focuses on inspecting springs for fatigue, dampers for leaks or loss of damping, bushings for wear, and ensuring proper alignment and tire condition. Worn fjæring can lead to reduced ride quality, poor handling, uneven tire wear, and compromised safety. Advances include adaptive damping and electronically controlled air suspensions.