An investigation has been conducted into the controversial phenomenon of weight-reduction of spinning wheels. When subjected to forced precession and controlled lifting, a spinning wheel does indeed lose 8% of its weight, as measured by a load-cell. That is, some of the gravitational potential energy acquired during lifting is supplied by the horizontal input force causing the enhanced precession. Consequently, the averaged vertical lifting force is less than Mg. The explanation for this phenomenon follows directly from the requirement of energy conservation throughout the process.