Pocket Bike racing, also known as Minimoto or circus racing, is a category of racing where miniature racing motorcycles (known as pocket bikes or minimoto) are raced around kart tracks. It is a popular sport in Japan and Europe and is gaining in popularity in other parts of the world.
A typical minimoto is approximately one-fourth the size of a regular motorcycle, and is powered by a two-stroke internal combustion engine of between 40–50 cc producing somewhere between 2.4 and 17 hp (1.8 and 11 kW). The machines have no suspension, relying on the tires to absorb bumps and handle cornering, and weigh approximately 50 lb (23 kg). The entry-level models produce about 2.4–4.2 hp, but the more expensive racing models can have a power output of about 11–17 hp. This provides a power-to-weight ratio favorable to racing. Despite their tiny size both adults and children race them at speeds of up to 78 mph (126 km/h) in organized racing leagues.
The ease of transportation and the low cost of the bikes (they are priced from approximately US$200 for a basic model built in China to around US$7,000 for a top of the line Italian model, making them an affordable way for children (some as young as six) to learn about motorcycle racing and for adults to race without the high costs and risks associated with full-sized motorcycle racing.
In most countries, a licence is not required to ride miniature bikes. However, they are usually not street legal and should be ridden on private land, such as car parks, gardens or on race tracks.
Miniature motocross motorcycles are also available for children to learn this form of motorcycling.
A notable racer who learned his craft on minimoto is Valentino Rossi.