By Clint Van Camp
It is a gorgeous summer day in Pembina County. You arrive at the Cavalier City Park shortly after 3 p.m. this afternoon. You walk over and plant your web chair under an oak tree on the hillside with a view of the stage. Then you head right over to the chute where Zero Gravity is ready to perform. With the revving of engines here come the bikes as they go airborne abo...