The foldable bearing structure includes a set of coplanar wheels and a folding device including a set of lower arms; at least a rear upper arm; an antiparallelogram deformable in a vertical plane, the antiparallelogram including two crossed segments; at least a first sidebar located in the vertical plane; the antiparallelogram deformed by folding between a first position corresponding to an unfolded of the structure and a second position corresponding to a folded position, the transition from the first position to the second position reducing the wheelbase of the structure.