Tire with greater resistance to unseating

A tire to be mounted on a mounting rim, comprising:

• two beads, which are capable of coming into contact with the mounting rim, each bead comprising an axially outer side and a radially inner seat;
• each bead in meridian cross-section having a radially innermost point, an axial width at seat D, and an external face comprised of the surface of the tire in contact with the outside of the tire and belonging to the bead, and each bead comprising a bead filler comprised of at least one rubber composition, a circumferential reinforcing element referred to as the main circumferential reinforcing element;
• the meridian cross-section of the main circumferential reinforcing element having a radially innermost point, a radially outermost point and an axially innermost point, the radially innermost point being positioned at a radial distance Z and at an axial distance Y from the radially innermost point of the bead;
• the axial width at the seat D being measured between the radially innermost point of the bead and the point of intersection between a first straight line tangential to the external axial projection of the radially innermost point of the main circumferential reinforcing element and a second straight line tangential to the internal radial projection of the axially outermost point of the main circumferential reinforcing element;
• a carcass reinforcement connecting the two beads and comprising a carcass layer extending in each bead radially towards the inside as far as a carcass layer end;
• for at least one said bead, the carcass layer end is radially on the inside of the point of greatest axial width (SM) of the tire and axially on the outside of the axially innermost point of the main circumferential reinforcing element,
• wherein, for each of the at least one said bead, the ratio Y/D between the axial distance Y from the radially innermost point of the main circumferential reinforcing element to the radially innermost point of the bead, and the axial width of the bead at the seat D, is greater than or equal to 0.5,
• wherein, for each of the at least one said bead, the ratio Z/D between the radial distance Z from the radially innermost point of the main circumferential reinforcing element to the radially innermost point of the bead, and the axial width of the bead at the seat D, is less than or equal to 0.4,
• wherein, each of the at least one said bead comprises a bead reinforcement, comprised of a bead layer, which surrounds the bead filler in such a way that the axially outermost end of the bead layer is radially on the outside of the radially innermost end of the carcass layer and such that the axially innermost end of the bead layer is radially on the outside of the radially innermost point of the main circumferential reinforcing element,
• wherein, for each of the at least one said bead, the bead reinforcement is close to but not contacting the external surface of the bead such that the points on the bead reinforcement which are positioned radially on the inside of the radially innermost point of the main circumferential reinforcing element are positioned, with respect to the closest portion of the external surface of the bead, at a maximum distance, measured perpendicular to the external surface of the bead, that is less than or equal to Z/2, half the radial distance Z between the radially innermost point of the bead and the radially innermost point of the main circumferential reinforcing element,
• and wherein, each of the at least one said bead comprises an additional circumferential reinforcing element, axially on the inside of the axially innermost point of the main circumferential reinforcing element, radially on the outside of a radially innermost part of the bead reinforcement and radially on the inside of the radially outermost point of the main circumferential reinforcing element.