Kart racing or karting is a variant of open-wheel motorsport with small, open, four-wheeled vehicles called karts, go-karts, or gearbox/shifter karts depending on the design. They are usually raced on scaled-down circuits. Karting is commonly perceived as the stepping stone to the higher ranks of motorsports.
Karts vary widely in speed and some (known as Superkarts) can reach speeds exceeding 260 kilometres per hour (160 mph), while amusement park go-karts intended for the general public may be limited to speeds of no more than 25 kilometres per hour (16 mph).
American Art Ingels is generally accepted to be the father of karting. A veteran hot rodder and a race car builder at Kurtis Kraft, he built the first kart in Southern California in 1956. Instantly popular, Karting rapidly spread to other countries, and currently has a large following in Europe.
The first kart manufacturer was an American company, Go Kart Manufacturing Co. (1958). In 1959, McCulloch was the first company, to produce engines for karts. Its first engine, the McCulloch MC-10, was an adapted chainsaw 2-stroke engine. Later, in the 1960s, motorcycle engines were also adapted for kart use, before dedicated manufacturers, especially in Italy (IAME), started to build engines for the sport.
The chassis are made of steel tubing. There is no suspension, therefore chassis have to be flexible enough to work as a suspension and stiff enough not to break or give way on a turn. Kart chassis are classified in the USA as ‘Open’, ‘Caged’, ‘Straight’ or ‘Offset’. All Commission Internationale de Karting – Fédération Internationale de l’Automobile or CIK-FIA approved chassis are ‘Straight’ and ‘Open’.
Open karts have no roll cage.
Caged karts have a roll cage surrounding the driver; they are mostly used on dirt tracks.
In Straight chassis the driver sits in the center. Straight chassis are used for sprint racing.
In Offset chassis the driver sits on the left side. Offset chassis are used for left-turn-only speedway racing.
The stiffness of the chassis enables different handling characteristics for different circumstances. Typically, for dry conditions a stiffer chassis is preferable, while in wet or other poor traction conditions, a more flexible chassis may work better. The best chassis allow for stiffening bars at the rear, front and side to be added or removed according to race conditions.
Braking is achieved by a disc brake mounted on the rear axle. Front disc brakes are used in most shifter kart classes and are increasingly popular in other classes; however, certain classes do not allow them. Shifter karts have dual master cylinders, one for the front and one for the rear and are adjustable to allow for front/ rear bias changes.
Professionally raced karts typically weigh 165 to 175 lb (75 to 79 kg), complete without driver. Avanti, Tony Kart, Trulli, Birel, CRG, Gillard, Intrepid, Kosmic, Zanardi or FA Kart are a few well known examples of the many European manufacturers of race-quality chassis. Emmick, Coyote, Bandit, Shadow, MGM, PRC and Margay are American companies producing kart chassis.
Amusement park go-karts can be powered by 4-stroke engines or electric motors, while racing karts use small 2-stroke or 4-stroke engines.
4-stroke engines can be standard air-cooled industrial based engines, sometimes with small modifications, developing from about 5 to 20 hp. Briggs & Stratton, Tecumseh, Kohler, Robin, and Honda are manufacturers of such engines. They are adequate for racing and fun kart applications. There are also more powerful four-stroke engines available from manufacturers like Yamaha, TKM, Swissauto or Aixro (Wankel engine) offering from 15 hp up to 48 hp. They run to and around 11,000 rpm, and are manufactured specifically for karting. Those are used in some National Championship classes like the two-strokes.
2-stroke kart engines are developed and built by dedicated manufacturers. WTP, Comer, IAME (Parilla, Komet), TM, Vortex, Titan, REFO, TKM, PRD, Yamaha and Rotax are manufacturers of such engines. These can develop from about 8 hp for a single-cylinder 60 cc unit (MiniROK by Vortex) to over 90 hp for a twin 250 cc. Today, the most popular categories worldwide are those using the TaG 125 cc units. The recent 125 cc KF1 engines are electronically limited at 16,000 rpm.