A segmented mold 2 for molding a tire 100 is described which has a central axis; plurality of radially movable tread forming segments; two sidewall forming plates, a top sidewall forming plate 8, and a bottom sidewall forming plate 6; a top locking ring 10 having a plurality of circumferentially spaced openings 30 for locking the segments 4, each opening for locking 30 providing a predetermined angular path 75 for radially contracting the segments 4 upon closing the mold 2 in a locked position. The segmented 2 mold for molding a tire 100 further has a bottom locking ring 20 having a complementary plurality of circumferentially spaced openings 30 for locking the segments 4, each opening for locking 30 providing a predetermined angular path for radially contracting the segments 4 upon closing the mold.