A sidecar is a one-wheeled device attached to the side of a motorcycle, scooter, or bicycle, making the whole a three-wheeled vehicle. A motorcycle with a sidecar is sometimes called a combination, an outfit, a rig or a hack.
An NSU Motorenwerke 601 motorcycle from the 1930s fitted with a Steib Metallbau sidecar
German bicycle sidecar carrying a child, 1927
German troops on motorcycles with sidecars invading the Soviet Union during Operation Barbarossa
Ukrainian Dnepr mt 10 with sidecar
A motorcycle is a two or three-wheeled motor vehicle steered by a handlebar from a saddle-style seat.
A classic Norton motorcycle
1955 NSU Lambretta 150 scooter
A cruiser (front) and a sportbike (background)
A Ural motorcycle with a sidecar