The competition between objects that roll on a ramp is an activity used frequently in the basic levels to challenge students’ previous ideas. From the perspective of the study of the dynamics of rotating objects, this is to show to the students the effect of the distribution of mass on their movement in order that the students infer or discover that an object with lower rotational energy will win the race. On the other hand, it is to highlight that the acceleration of rolling objects does not depend on their radios and their masses. In this work, a critique of the approach the textbooks have on this problem is presented and the ideas, students revealed as predictions in an activity of Predict – Observe – Explain, are reported. Students only made use of their previous ideas related to friction, mass and weight. They were essentially unable to identify the distribution of mass as a decisive cause in the movement of different rolling objects (inserted rings competing with another parallel ring and a ring with an inserted cylinder).