This paper outlines the solution that the Team of Austria found to problem number 7, "skateboarder", presented in the finals of the 22nd International Young Physicists' Tournament (IYPT) in Tianjin, China. We investigated how a skateboarder can accelerate from rest on a horizontal surface without touching an external support. The focus was laid on a tic-tac, which is a repeated turning of the whole body and the skateboard from one side to the other. We based our investigation on papers examining the acceleration in slalom skateboarding. We performed video analyses to give a qualitative explanation and gathered quantitative data on the motion of the skateboarder using an inertial measurement unit. It was shown that an important feature of a tic-tac is that the pivot in the rotation is not in the middle of the rear truck. This makes acceleration possible even if the deck is not tilted. With the mathematical analysis we put forward, we could calculate the effects of the controlling motions the skateboarder performs on the velocity of the skateboard as a system with non-holonomic constraints. Subsequently, we show that the calculations are in general agreement with our experimental data. Previous assumptions for the frictional forces were revised and we suggest a more accurate method to measure the wheel angle through the tilt of the deck. (Contains 1 footnote and 7 figures.)