While tubes represent a fundamental ingredient in the chassis of a kart, another critical element is the geometry of the frame. In this sense, it is worth comparing the Invader and the Le Mans, another model made by Parolin that has already been analysed by TKART
Looking at the drawing of the design of the Invader chassis, you can see that the longerons are slanted towards the inside of the kart in the area near the tank: that decision was made in order to move the torsion point towards the front end of the kart. In practical terms, this set-up means the chassis enters bends more readily, a particularly important factor in the shifter classes, in which the driving style requires the vehicle to enter aggressively, sacrificing smoothness.
Moving on to the rear end, note the position of the crossbar, further back compared to the Le Mans in order to give the chassis more grip and traction when exiting bends.
Another important aspect are the high bearing carriers: a decision that has always been made to favour use in KZ classes, increasing lateral grip.
Increasing stiffness, on the other hand, is the aim of the small tube with a reduced diameter that joins the two main 32 mm tubes in the area in which the engine is bolted in place. It guarantees additional strength to accommodate the KZ engine, which is heavier and more powerful than that of a non-shifter.