What is "freewheelers"

Freewheelers is a British television series made by Southern Television between 1968 and 1973. It was the brainchild of television producer Chris McMaster, who was aware of the popularity of adult action series such as The Avengers and Department S amongst teenagers and saw the potential of a version aimed at a younger audience. In 2010, reruns of Freewheelers were being shown on the British satellite television channel Film 24.