A tire, a wheel rim and assembly thereof in which the tire includes a pair of sidewalls each having a lower sidewall and a bead including a circumferentially extending hoop or bead core characterised by the bead extending laterally outwards of the tire to define with the lower sidewall a groove opening in the laterally outward direction and to form a space between the bead and a rim well portion of the wheel rim. The wheel rim included a pair of laterally inwardly projecting tire engaging members, each having a bead seat and the radially inner surface thereof. The tire, the rim and the assembly are light weight and easy to assemble.