Abstract: A retreading curing ring is disclosed. The ring includes a body member which defines a circular platform. A plurality of clamps are mounted at circumferentially spaced locations on the body members. The clamps are movable between an open and a closed position. A tire retreading assembly including a tire carcass and new retread tread stock is positioned within a flexible bag or envelope. Guides center the tire with respect to the circular platform. The envelope is sandwiched between the upper surface of the circular platform of the curing ring and the sidewall of the tire. When the clamps are moved to the closed position, an air tight seal is formed.