Report on failure testing of forty-two tires

Abstract

This is the final report of an experiment done by UMTRI to determine the inflation pressure required to fail 16 inch light truck tires, when improperly mounted on 16.5 inch wheels. In an interim report titled "Report on Failure Testing of Thirty Tires" UMTRI reported on the test results of thirty tires fro six different manufactures. In this final report, the test results of twelve more tires from two additional manufactures are also considered. It is possible to improperly mount a 16 inch tire (metric 215/85, in this case) on a 16.5 inch tire wheel. When this is the case, the tire bead makes an air tight seal against the improper seating generates excessive stresses in the tire bead wire. Eventually, failure of the wire and explosive deflation of the tire will occur as the integrity of the bead seat is lost. Such a failure was obtained for each of the forty-two tires tested.