A gyrocar is a two-wheeled automobile. The difference between a bicycle or motorcycle and a gyrocar is that in a bike, dynamic balance is provided by the rider, and in some cases by the geometry and mass distribution of the bike itself. In a gyrocar, balance was provided by one or more gyroscopes, and in one example, connected to two pendulums by a rack and pinion.

The concept was originally described in fiction in 1911 "Two Boys in a Gyrocar: The story of a New York to Paris Motor Race" by Kenneth Brown, (Houghton Mifflin Co). However the first prototype Gyrocar, The Schilovski Gyrocar, was commissioned in 1912 by the Russian Count Pyotr Shilovsky, a lawyer and member of the Russian royal family. It was manufactured to his design by the Wolseley Tool and Motorcar Company in 1914 and demonstrated in London the same year. The gyrocar was powered by a modified Wolseley C5 engine of 16 - 20 hp, with a bore of 90 mm and a stroke of 121 mm. It was mounted ahead of the radiator, driving the rear wheel through a conventional clutch and gear box. A transmission brake was fitted after the gearbox- there were no brakes on the wheels themselves. The weight of the vehicle was 2.75 tons and it had a very large turning circle.