A vehicle rim, of revolution, intended for mounting a tire and an annular bearing support capable of supporting a tread of the tire in the event of a loss of inflation pressure from the tire, this rim comprising (i) a first and a second rim seat, each of the rim seats being intended to receive a bead of the tire, each of the rim seats having a generatrix the axially inner end of which is on a circle of diameter DI greater than the diameter DE of the circle on which the axially outer end is located, the first rim seat being delimited axially to the inside by a protrusion the external diameter DS of which is greater than the mean diameter DP of the supporting bearing surface; (ii) a supporting bearing surface formed of at least one substantially cylindrical surface of revolution of mean diameter DP extending axially between the two seats and intended to be in close contact with the bearing support; and (iii) a circumferential groove located axially between the supporting bearing surface and the first rim seat, the axial width LG of the groove being adapted to permit the support to pass over said protrusion.