the front and rear tires were just moving around in the areas between the grate. Some bikes and tires feel worse than others because of the design. My zx6r and drz felt ok on that part but a hawk gt I was riding scared the hell out of me on the JBR. It feels shitty going over those grates no matter what you do but just keep a steady speed, loosen up, don't hit your brakes and you should be fine