Abstract: A method of operating a flywheel (10) includes the provision of a central shaft (12) defining an axis of rotation; providing a disk-shaped hub (22) joining drivingly with both the shaft and with a rim portion (34); and which hub portion has a shape when the flywheel is at rest which is of a shallow dihedral geometry. That is, the hub is cone-shaped when the flywheel is at rest. As the rotational speed of the flywheel is increased from the at-rest speed toward and then to a design operating speed for the flywheel, this hub progressively flattens out until it becomes flat and extends radially between the shaft and the hub at the design speed for the flywheel. Thus, the flattening of the hub with increasing rotational speed for the flywheel moves the rim portion axially in response to centrifugal force.