Thunder in the Valley has become one of the biggest motorcycle rallies in the country. Period. Some estimates put it at 250K in and around Johnstown. Put on a free event anywhere near the center of the action and you'd better have that kind of crowd. That's expected.
It is great exposure in a filled-to-the-rim area. I for one hope you sell tickets to at least a third of those in attendance for the free event. Exposure AND SELLING TICKETS is the main focus. Good luck!