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 includes a first and a second rim seat, each intended to receive a bead of the tire. Each of the rim seats has 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 is delimited axially to the inside by a protrusion, the external diameter DS of which is greater than the mean diameter DP of a supporting bearing surface of the rim. The supporting bearing surface is 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. A circumferential groove is 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 the protrusion.