Motorcycle fairing

A motorcycle fairing is a shell placed over the frame of some motorcycles, especially racing motorcycles and sport bikes, with the primary purpose to reduce air drag. The secondary functions are the protection of the rider from airborne hazards and wind-induced hypothermia and of the engine components in the case of an accident. A motorcycle windshield may be an integral part of the fairing.

The major benefit of a fairing on sport touring and touring motorcycles is a reduction in aerodynamic drag, which allows for reduced fuel consumption and permits higher speeds at lower engine rpm, which in turn increases engine life.

A motorcycle may have a front fairing, a rear fairing, a belly fairing, or any combination of these. Alternatively, a single fairing may partially or fully enclose the entire motorcycle, and may even enclose the rider.

The importance of streamlining was known very early in the 20th century, and some streamlining was seen on racing motorcycles as early as the 1920s. Although motorcycles generally have a much higher power-to-weight ratio than cars, bikes – and particularly the rider – are much less streamlined and the effects of aerodynamic drag on motorcycles are very significant. Consequently, any reduction in a motorcycle's drag coefficient pays dividends in improved performance.

The term fairing came into use in aircraft aerodynamics with regard to smoothing airflow over a juncture of components where airflow was disrupted. Early streamlining was often unsuccessful resulting in instability. Handlebar fairings, such as those on Harley-Davidson Tourers, sometimes upset the balance of a motorcycle, inducing wobble.

Originally the fairings were cowlings put around the front of the bike, increasing its frontal area. Gradually they became an integral part of the design. Modern fairings increase the frontal area at most by 5% compared to a naked machine. Fairings may carry headlights, instruments, and other items. If the fairing is mounted on the frame, placing other equipment on the fairing reduces the weight and rotational inertia of the steering assembly, improving the handling.

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