Flat-base rim for heavy truck tubeless tire and assembly of such a rim with a tire

An assembly of a rim and a tire of "heavy truck" type and form ratio less than 0.80, said rim comprising a rim base and two side rings removably mounted on the rim base at axially opposite ends thereof

• each side ring including a tire seat and a flange, the seat, viewed in meridian section, having a radially outer face formed of a frustoconical generatrix forming with the axis of rotation of the rim an angle of between 0.degree. and 15.degree. which outer face is connected with the outer face of the flange by a circular arc,
• each side ring having a radially inner face which includes an axially inner cylindrical portion of axial width between L+H(H+h)/2 and L+(H+h) and an axially outer frustoconical portion the generatrix of which forms an angle of between 10.degree. and 35.degree. with the axis of rotation, L being the axial width of the frustoconical seat, H being the height of the flange from the radius R.sub.S measured from the axis of rotation of the rim to the largest circumference of the frustoconical seat and h being the thickness of the seat equal to Rs-Re, Re being the radius of the cylindrical portion of the inner face of the side ring,
• each side ring being formed of a material between the radially outer face of the flange and the radially inner face of the ring which material is reinforced by an annular reinforcement element, the circumferential length of which is extendable by at least 3% and having a cross section the maximum radial dimension of which is between (H+h) and H, the deformation of the section under compression stress being less than 2% and
• said rim base having a cylindrical part of radius equal to kRe, k being between 1.02 and 1.05, this cylindrical part extending axially to the outside by frustoconical parts, the generatrices of which from angles within the range of .alpha..+-.2.degree. with the axis of rotation, the maximum radii of these frustoconical parts being such that the dimension [R.sub.f +(H+h)]-R.sub.J is less than the maximum radial dimension of the annular reinforcement element cross section, the angle .alpha. being the angle formed by the generatrix of the frustoconical portion axially to the outside of the cylindrical portion of the ring inner face, R.sub.F being the radius of the rim base cylindrical part and R.sub.J the maximum radius of the rim base frustoconical part, and
• said tire having beads and a carcass reinforcement, at least two circumferentially unstretchable annular elements having spaced apart faces in the beads, the carcass having ends which are clamped between the two faces, said faces being flat and parallel to each other over an axial distance at least equal to 15 mm and inclined with respect to the axis of rotation by an angle, open towards the outside of the tire, of between 5.degree. and 30.degree., one of the elements extending radially above portions of the ring flange and seat, the minimum radius R.sub.p of the annular elements closest radially to the axis of rotation being at least equal to the maximum radius R.sub.j of the rim on which the tire is mounted.