Gearbox Karts: 125cc gearbox kart categories (formerly called Formula C and ICC) are now regrouped under the appellation KZ and, at CIK-FIA level, come in as KZ1 and KZ2. There are almost no technical differences between these two classes.
Having long remained confidential in many countries, the use of gearbox karts has considerably been extended over the last decade, thanks notably to very stable technical rules. The foundations of engine homologation were implemented in 1998 and have practically not changed since. This lasting success is due to these ingredients: A cylinder capacity of 125cc, inlet by means of a reed-box, single-carburettor designated further to an invitation to tender, homologated exhaust and 6-gear sequential gearbox with limited ratio variants.
The gearbox karts are the fastest karts that compete on designated karting circuits. The races have standing grand prix starts, and the karts and are truly spectacular to watch, and race!
