Abstract: A semi-pneumatic tire assembly including a tire casing 22 and a lining 26 is provided. The lining 26 includes a contoured inward surface 30 defining an inflation chamber 18 about an associated wheel rim. The lining 26 minimizes the risk of puncture damage from an object penetrating the tire casing 22 while allowing pneumatic cushioning of the ride and cooler running temperatures as compared to solid-fill tires. Additionally, the semi-pneumatic tire will carry the same load or more than the same tire filled with permafoam and/or solid urethane foam wingfil. The tire assembly is formed by injecting a curable, lining-forming material 96 into a cavity 57 defined between the tire casing 22 and a molding member 50. The molding member 50 includes a contoured outer surface 54 which molds the inward surface of the lining 26. The molding member 50 may be an inflatable airbag 100 retained in the tire assembly during service.