The invention discloses an adapter for a rolling assembly and the rolling assembly comprising the same. The invention relates to an adapter for a rolling assembly having an axis of rotation and comprising a tyre having two beads and a rim, said adapter providing the connection between one of the rib beads and the rim, said rim having two rim seats (7), said adapter having an axially internal end (10) intended to be mounted on the seat of the rim and comprising an internal reinforcing element (16), an axially external end (9) intended to be mounted on the seat of the rim and comprising an external reinforcing element (15), a body (11) connecting said external end to said internal end in such a way as to form a single unit and comprising at least one main reinforcement providing the connection between said external reinforcement and said internal reinforcement, a substantially cylindrical adapter seat (18) intended to accept one of said beads, an adapter bearing face (21); substantially comprised in a plane perpendicular to the axis of rotation. The adapter is characterized in that the reinforcement of the axially external end is entirely outside the bearing face, and in that the body comprises, facing the adapter seat, a seat annular reinforcement that has a compression modulus of 1 GPa or more.