Buster Keaton was a comedy film star during the early silent era of Hollywood cinema. He was famous for the numerous dangerous stunts that featured in his movies. Some of these would involve utilising motor vehicles.
In Sherlock Jr. (1924) he uses a fast motorcycle for great comedic effect. Keaton plays a detective who is running down a road. He spots a policeman on a bike and hops onto the handlebars, sitting on them and instructing the rider to follow a villain.
After hitting a pothole the policeman is thrown off the bike, leaving it driverless. Keaton manages to control it even in his unusual sitting position. He maintains its speed, narrowly missing a number of oncoming cars.
He does this while still believing that the policeman is sitting in the bike. It should be remembered that no special effects were employed for this sequence Keaton managed to do all the death defying stunts himself.
While filming this scene Keaton was involved in an accident. The bike he was using for the stunt lost control, skidded and crashed into two of the cameras. Despite this, Keaton was not seriously harmed and continued filming.