A post-cure inflator wherein an upper rim is automatically exchanged. A locking shaft is mounted for rotation on a rotary frame, and an upper rim support is mounted for rotation on the locking shaft. An upper rim is removably supported on the upper rim support. Also a lower rim support is removably supported on the locking shaft, and a lower rim is removably supported on the lower rim support and cooperates with the upper rim to hold therebetween a vulcanized tire, into which high pressure air is blown to inflate and cool the tire. The upper rim support and the upper rim have cooperating tapered fitting portions, and the upper rim has an outer peripheral circumferential groove formed at an upper portion thereof. A latching member is mounted on the upper rim support for movement into and out of the outer peripheral circumferential groove of the upper rim. The upper rim support includes a first member secured to the rotary frame and a second member mounted for movement into and out of contact with the first member, and a lifting apparatus is disposed on one of the first and second members and moves the second member toward and away from the first member.