A childhood belief about in the street

When I was young there were a few pedal cycles in our village. We all knew that the rider had to pedal, with the legs going up and down in turn, to get the bicycle to move. On a rare occasion, the sanitary inspector came on his motorcycle. I was convinced, though, that the wheels of the motorcycle did not turn: they just glided on the road. Did anybody see the rider pedaling? No, all that the man did was to sit comfortably with bent knees without moving his legs at all.