Abstract: An apparatus and a process for cold cure retreading of worn tires using a fully pre-cured tread band bonded in place on said tire by means of a layer of cushion gum. In order to cure the layer of cushion, gum, steam is supplied to a rubber tube disposed within the tire which itself is mounted on a suitable rim assembly, and steam at a lesser pressure is supplied to an annular steam chamber whose inner wall is constituted by a steam impervious flexible bladder that circumscribes the crown portion of the tire assembly. Cone elements are disposed on either side of the tire assembly to support the bladder and prevent excessive bulging thereof beyond the crown portion of the tire.