Pneumatic tire with bead regions having circumferentially extending ribs

摘要

A radial tire having bead regions each comprising a bead clinch and a bead seat has between two and ten circumferentially extending ribs projecting outward of the bead region outer surface. The ribs are preferably continuous around the circumference of the tire bead and project outward from the bead region outer surface by a distance not greater than 8%, more preferably not greater than 3%, of the bead base width. Also the ribs preferably have a maximum width of between 5% and 15%, most preferably 10%, of the bead base width. The rib surface most preferably comprises a continuous surface of an arc and straight portion meeting tangentially.