A sidecar is a one-wheeled device attached to the side of a motorcycle, producing a three-wheeled vehicle. Early sidecars were intended to be removable devices that could be detached from the motorcycle. The first mention of a sidecar is in a cartoon by George Moore in the January 7, 1903 issue of the British newspaper "Motor Cycling". Three weeks later a provisional patent was granted to Mr. W. J. Graham of Graham Brothers, Enfield, Middlesex. A motorcycle with a sidecar is sometimes called a combination, an outfit, a rig or a hack.

Structure

A sidecar motorcycle is a three wheel vehicle with the sidewheel not directly aligned with the rear motorcycle wheel, and is usually powered by the rear wheel only. This is different from a motorcycle trike, where both rear wheels are powered and share a common axle. However, either P.V. Mokharov of the Soviet Union or H.P Baughn of Great Britain seem to have to been the first to employ a driven sidecar wheel in 1929. In fact Baughn 2WD outfits were so successful in trials events in the early 1930s that there were attempts to have the ACU ban them from competition. A great many companies experimented with 2WD in sporting events and indeed many companies employed them in military vehicles prior to the commencement of WWII.

The sidecar consists of a frame (which is rigidly fixed to the motorcycle's frame on one side and is supported by the sidecar's wheel on the other side) and of a body. The body typically provides one passenger seat and a small trunk compartment behind. In some case the sidecar has a removable soft top. In some modifications the sidecar's body is used for carrying cargo or tools (like a truck's platform).

A sidecar completely changes the geometry of a motorcycle, which then must be steered like a car, rather than countersteered. If the sidecar is not attached properly it will make the motorcycle unstable.