The present invention consists of both a method and apparatus for providing the upper and lower portions of two-part tire molds with an expansible opening to provide clearance for the insertion of green tires, in particular large green tires of the sort used on industrial or off-road vehicles. The tire mold according to the present invention provides a segmented tire mold wherein a plurality of circumferentially arranged segments that contribute to the shaping of the circumferential tread portion of a tire being molded are able to move in such a way as to include a radial component of motion that provides a larger diameter for each of the two mold portions during the green tire loading operation. Thus the internal circumferential region of the top portion and of the bottom portion is able to expand in diametrical dimension when the two part tire mold is open.