The collaboration between the Tony Kart Racing Team (Tony Kart’s official racing department) and the OTK Kart Group R&D department has a double fundamental role: on the one hand it guides the design of new components and the refinement of those already being used, ensuring greater performance and constancy of operation, but not only, because it also affects the choice of the right materials based on the type of component use. For example, despite one of the historical characteristics of Tony Kart chassis is that of having accessories only made of magnesium. The company has recently chosen to switch to high quality forged aluminium for the production of some components, such as the pedal set and bearing housing shells. The reasons are, on the one hand, the environmental impact generated by some stages of magnesium production/treatment and, on the other, the excessive wear of specific components, such as the axle bearing flanges. The difference between magnesium and ergal is important: the former has certain physical qualities, such as a low specific weight and a higher thermal conductivity, which make it ideal for the production of those accessories that require good heat dissipation (disc housing, gear wheel housing, wheels and wheel hubs), while the second has better mechanical characteristics including greater resistance and less wear. Therefore it is preferable to make parts subjected to considerable mechanical stress. The new Tony Kart 401 RR Racer, approved for both direct-drive and shifter classes (the version discussed in this article), is a direct evolution of the Racer 401 R (model launched in 2019 which you can read about in the Dedicated “Under review” article. OTK technicians were faced with the difficult task of perfecting a chassis that overall had proved to be complete and, above all, a winner.