Sidehackers

The Sidehackers (also known as Five the Hard Way) is a 1969 American action film about motorcycle racing with a twist. Each motorcycle has a sidehack (a sidecar with a rail but no sidewalls or seat), in which a passenger rides and tilts to one side or the other when going around curves. The credits thank the "Southern California Sidehack Association"; sidehacking is also known as sidecarcross or "sidecar motocross racing".