Most information I have been able to find indicates that cupping of the front tire on a motorcycle is normal, if both sides are cupped equally. Apparently it is supposed to be a function of soft, sticky compounds on the sides for better cornering, and tougher rubber at the center for better wear. Some say the width and type of tire belt plays a role, too, as to where the cupping occurs. Riding habits influence the severity and speed of cupping. Insufficient shock dampening is popularly said to be a cause, but I can find no authoritative verification of that forum theory. I only bother to change out a front because of cupping when it becomes pronounced enough to "grab" and cause handling issues.
On a car, cupping is limited to one side of the tire (or tires), and is almost always caused by worn suspension components. On the Spyder, it should be the same. I'd check for worn ball joints, tie-rod ends, Heim joints, shock bushings, and/or wheel bearings.
