Some car tire manufacturers, such as Bridgestone, Dunlop or Maxxis, make tires for karts. In international level racing these are some of the softest and most advanced tires in motorsport. Similar to other motorsports, kart tires have different types for use appropriate to track conditions:
Tires can support cornering forces in excess of 2 'g' (20 m/s²), depending on chassis, engine, and motor setup. Rims are made of magnesium alloy or aluminum. Wheels and tires are much smaller than those used on a normal car. Dry centrifugal clutches are now used in many categories ( Rotax Max is one example) and have become the norm as the top international classes have switched to 125 cc clutched engines as of January 2007. In the early days, karts were direct drive only, but the inconvenience of that setup soon led to the centrifugal clutch for the club level classes. Both engine and axle sprockets are removable their ratio has to be adapted according to track configuration in order to get the most from the engine. Power is transmitted from the engine to the rear axle by way of a chain. This allows the tire to lose some of its grip and slide or lift off the ground completely. The lack of a differential means that one rear tire must slide while cornering this is achieved by designing the chassis so that the inside rear tire lifts up slightly when the kart turns the corner.
Most are water-cooled today however, previously air-cooled engines dominated the sport. The recent 125 cc KF1 engines are electronically limited at 16,000 rpm. Today, the most popular categories worldwide are those using the Touch-and-go (TAG) 125 cc units. These can develop from about 8 hp for a single-cylinder 60 cc unit (MiniROK by Vortex) to 90 hp for a twin 250 cc. WTP, Comer, IAME (Parilla, Komet), TM, Vortex, Titan, REFO, TKM, PRD, Yamaha and Rotax are manufacturers of such engines.
The stiffness of the chassis enables different handling characteristics for different circumstances. Offset chassis are used for left-turn-only speedway racing.
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. Its first engine, the McCulloch MC-10, was an adapted chainsaw 2-stroke engine. McCulloch was the first company, in 1959, to produce engines for karts. The first kart manufacturer was an American company, Go Kart Manufacturing Co. Karting has rapidly spread to other countries, and currently has a large following in Europe. A veteran hot rodder and a race car builder at Kurtis Kraft, he built the first kart in Southern California in 1956. Kart racing in the streets of East Berlin in 1963Īrt Ingels is generally accepted to be the father of karting.