Gira, gira …

The motion of a free revolving bicycle wheel, gently slowed down by air drag and bearings friction, was studied through an experiment done in the Physics laboratory of a secondary school. The experimental data were compared with different hypothesis on the resisting torque, with the aid of computer programs. Here we explain this experiment and the educational goals attained in the classroom; warning suggestions are also given for those who would like to follow a similar teaching strategy with a different wheel.