Retrograde motion of a rolling disk

This paper presents results of theoretical and experimental research explaining the retrograde final-stage rolling of a disk under certain relations between its mass and geometric parameters. Modifying the no-slip model of a rolling disk by including viscous rolling friction provides a qualitative explanation for the disk's retrograde motion. At the same time, the simple experiments described in the paper completely reject the aerodynamical drag torque as a key reason for the retrograde motion of a disk considered, thus disproving some recent hypotheses.