I have been using polyurethane bumpers - McMaster Carr p/n 9546K133 - for aileron stops on my G202 for many years now. For my plane this was a simple replacement of the existing stop bolts. You want to check pushrod clearance carefully with the bumpers fully compressed. This significantly cushions the shock load on hitting the aileron stop for full deflection rolls. Andrew Wright andrew@carbonfiberairshows.com