*Article* **Quasi-Static Research of ATV/UTV Non-Pneumatic Tires**

**Jerzy Jackowski 1, Marcin Zmuda ˙ 1,\*, Marcin Wieczorek <sup>1</sup> and Andrzej Zuska <sup>2</sup>**


**Abstract:** The non-pneumatic tire (NPT) is a type of wheel whichdevelopment is related to the beginning of automotive development. The non-pneumatic tire (NPT) is a type of tire that does not contain compressed gases or fluid to provide directional control and traction. Nowadays, this type of wheel is more and more often used in special purpose vehicles, e.g., in military vehicles and working machines. The main feature of the non-pneumatic tire is a flexible support structure (including the part of the wheel between the tread and the rim). This paper presents the results of research aimed at determining the influence of the geometry of the NPT's (intended for All-Terrain Vehicle– ATV/Utility Task Vehicle–UTV) load-bearing structure on its quasi-static directional characteristics. The experimental tests included the determination of the radial stiffness of research objects on a non-deformable flat surface and on a single obstacle, as well as the determination of the degree of deformation for the elastic structure and belt. The significant influence of the elastic structure's shape and the elastomer, as the material forming the NPT, on its radial stiffness was revealed.

**Keywords:** non-pneumatic tire; airless tire; radial stiffness; spoke deformation
