A non-pneumatic tire has a crown region and a pair of sidewall regions, including a first sidewall region and a second sidewall region. The non-pneumatic tire includes a pair of beads, including a first bead and a second bead, and a toroidal element. The toroidal element includes an inner region, an outer region, and a central region. At least a portion of the central region is more elastic than the inner and outer regions. The toroidal element includes a crown portion extending across the crown region of the non-pneumatic tire, a first sidewall portion extending along at least a portion of the first sidewall region of the non-pneumatic tire, and a second sidewall portion extending along at least a portion of the second sidewall region of the non-pneumatic tire. The toroidal element is pre-stressed such that when the non-pneumatic tire is mounted to a rim, the first sidewall portion of the toroidal element exerts a first axially outward force of at least 1000 pounds against the rim, and such that the second sidewall portion of the toroidal element exerts a second axially outward force of at least 1000 pounds against the rim.

A tire includes at least one body defining a plurality of body ply layers, and a toroidal element located between the body ply layers. The toroidal element includes inner and outer regions formed by the body ply layers, and a central region formed by an inner rubber component located between the body ply layers. At least a portion of the central region is more elastic than the inner and outer regions. The toroidal element includes a first sidewall portion extending along at least a portion of the first sidewall region of the tire, and a second sidewall portion extending along at least a portion of the second sidewall region of the tire. The toroidal element is pre-stressed such that the first sidewall portion of the toroidal element exerts a first axially outward force, and such that the second sidewall portion of the toroidal element exerts a second axially outward force.

A method of assembling a tire having one or more reinforcements or supporting inserts in the sidewalls is provided. The reinforcements are positioned onto one or more air impermeable layers. One or more reinforcing plies are positioned over the reinforcing supports and suspended therebetween. A gas pressure is used to expand the one or more air impermeable layers away from the forming drum and against a reinforcing ply. As such, the creases or wrinkles in the one or more reinforcing plies can be avoided along with other non-uniformities such as deradialization and/or an uneven overlap where the ends of a ply are joined.