Measures, quantities, percentages. All the most significant numbers of kart

LET US GIVE THE KART’S NUMBERS

TKART Staff

29 April 2020

Sports is a dream and passion. True, but it is also technique, rules and numbers! In particular, in motorsports where measures, quantities and percentages (whether or not determined by the regulations) are essential rules that you should know in order to find your bearings and become a karting expert. Karting is certainly no exception. Let us find out its most significant “numbers”

CHASSIS

The chassis is the component of the kart which, for many years, seems to be the least part to be redesigned. Compared to the first chassis, with a decidedly elongated rectangular and, at times modular in shape, the design appears today to be substantially definitive although some original experiments are not missing. With the limits imposed by the regulations, the manufacturers’ research and development efforts have focused on the tubes’ materials, treatments and the optimization of the welding process.

30 mm is the most widely used tube diameter measurement adopted by most manufacturers. Chassis built with 30 mm tubes are used both in single-speed and shifter categories, although the shifter category often includes chassis with either all 32 mm tubes or mixed 30-32 mm tubes. Chassis in the MINI category, on the other hand, use exclusively 28 mm tubes as per the regulations.

50mm is the maximum diameter allowed by the regulation for the rear axle. It is not, therefore as one may be led to think, the only diameter allowed. Smaller sizes can be used provided that the minimum thickness (which for 50 mm axles is of 1,9 mm) varies accordingly. A 40 mm axle, for example, must be 2,9 mm thick. In Super-Karts, instead, where a 40 mm axle is mandatory, the thickness must be 2,5 mm. Finally, in Mini-Karts, the axle’s diameter must not exceed 30 mm for a thickness of 4,9 mm.

6 is generally the quantity of tubes used to make a chassis. More specifically, it is the front tube in which the “Cs” are welded. The two main longerons and the secondary longeron on the right side where the engine is mounted and the two transverse tubes on which the seat is then fastened. Even in the chassis dedicated to the MINI the number of tubes used is always 6.

25CrMo4

More than a number, in this case, it is a formula. That of the main type of steel used to make the tubes for the kart. In general, all manufacturers choose chromium-molybdenum alloy steel which also made ad hoc. The choice is that of the treatment to be applied to all the tubes needed. The prohibitions concern the use of materials such as carbon fiber, stainless steel and titanium as, per the regulations, the chassis must be made of magnetic material. Chromium-molybdenum steel is the ideal choice both in terms of performance and cost for a vehicle without a suspension such as the kart.