A method for determining the aerodynamic moment of resistance M.sub.aero-EM of a wheel by calculating the variation with respect to time, of the product of the rotational speed of at least one wheel set in rotation about an axis and of the inertia of the said wheel about the said axis, the wheel being equipped with a device for picking off and recording the numerical values of its rotational speed. The wheel is protected by a removable cap and in is subjected to a flow of air.

A method for determining the aerodynamic moment of resistance M.sub.aero-EM of a wheel by calculating the variation with respect to time, of the product of the rotational speed of at least one wheel set in rotation about an axis and of the inertia of the said wheel about the said axis, the wheel being equipped with a device for picking off and recording the numerical values of its rotational speed. The wheel is protected by a removable cap and in is subjected to a flow of air.