Tyre casing in the shape of a torus around a reference axis equipped with a passive radiofrequency transponder (1, 1bis, 1ter) and comprising: - a crown block comprising a crown reinforcement having an axial end at each of its edges and a tread, joined at each of its axial ends to a bead having an inner end, located axially and radially on the inside of the bead with respect to the reference axis, via a sidewall, - a carcass reinforcement, comprising at least one carcass reinforcement layer formed of mutually parallel reinforcing elements, defining a reinforcement direction, and which are inserted between two skim layers of elastomeric compound, - said at least one carcass reinforcement layer being anchored in each of the beads by being turned up around an annular bead wire to form a main part of the at least one carcass reinforcing layer, extending from one bead wire to the other and situated radially on the inside with respect to the crown block, and a turn-up of the at least one carcass reinforcement layer in each of the beads, - a second layer of elastomer compound forming the exterior surface of the tyre casing in the region of the bead, said second layer of elastomer compound being intended to come into contact with the rim, - a third layer of elastomer compound situated radially on the outside in contact with the second layer of elastomer compound forming the exterior surface of said sidewall, - the passive radiofrequency transponder (1, 1bis, 1ter), comprising a main core defining a first longitudinal axis, a first primary cover filament wound in turns around the main core defining a winding diameter D and an electrical insulation device disposed radially on the outside of the first primary cover filament with respect to the first longitudinal axis; - the first primary cover filament comprising at least two conductive filamentary elements (1003a, 1003b), the diameter of which is between 0.05 and 0.15 millimetres, galvanically connected to at least one electronic chip comprising a radiofrequency transmission-reception component; - the main core having a stiffness lower than the maximum stiffness of the first primary cover filament (1013a, 1013b); the electrical insulation device having a mean relative dielectric permittivity less than or equal to 10, preferably less than 5, over a thickness greater than or equal to one sixth of the winding diameter D of the first primary cover filament, the passive radiofrequency transponder (1, 1bis, 1ter), in its longitudinal direction, being located in line with at least two reinforcing elements of the main part of the at least one carcass reinforcement layer, the passive radiofrequency transponder being located axially on the outside of the inner end of the bead and radially between the radially outermost end of the bead wire and the axial end of the crown reinforcement, preferably on the inside of the tyre casing and the thickness of elastomer compound separating the outer cover filament (10113a, 1013b, 1024, 1025) of the passive radiofrequency transponder (1, 1bis, 1ter), located radially outermost with respect to the first longitudinal axis, and the reinforcement elements being greater than 0.5 millimetres, preferably greater than 1.0 millimetre. - a crown block comprising a crown reinforcement having an axial end at each of its edges and a tread, joined at each of its axial ends to a bead having an inner end, located axially and radially on the inside of the bead with respect to the reference axis, via a sidewall, - a carcass reinforcement, comprising at least one carcass reinforcement layer formed of mutually parallel reinforcing elements, defining a reinforcement direction, and which are inserted between two skim layers of elastomeric compound, - said at least one carcass reinforcement layer being anchored in each of the beads by being turned up around an annular bead wire to form a main part of the at least one carcass reinforcing layer, extending from one bead wire to the other and situated radially on the inside with respect to the crown block, and a turn-up of the at least one carcass reinforcement layer in each of the beads, - a second layer of elastomer compound forming the exterior surface of the tyre casing in the region of the bead, said second layer of elastomer compound being intended to come into contact with the rim, - a third layer of elastomer compound situated radially on the outside in contact with the second layer of elastomer compound forming the exterior surface of said sidewall, - the passive radiofrequency transponder (1, 1bis, 1ter), comprising a main core defining a first longitudinal axis, a first primary cover filament wound in turns around the main core defining a winding diameter D and an electrical insulation device disposed radially on the outside of the first primary cover filament with respect to the first longitudinal axis; - the first primary cover filament comprising at least two conductive filamentary elements (1003a, 1003b), the diameter of which is between 0.05 and 0.15 millimetres, galvanically connected to at least one electronic chip comprising a radiofrequency transmission-reception component; - the main core having a stiffness lower than the maximum stiffness of the first primary cover filament (1013a, 1013b);