A spoke including a metallic core covered, at least in its central portion, with a sheath of composite material comprised of an assembly of fibers embedded in a matrix, the core including an end portion adapted to be attached to the rim or the hub of a wheel, and a main body whose cross-sectional surface area is between 30% and 50% or, in a particular embodiment, between 35% and 45%, of the cross-sectional surface area of the aforementioned end portion. Furthermore, in the area of the main body, the sheath has a cross section between 150% and 500% or, in a particular embodiment, between 150% and 350%, of the cross section of the metallic core in the same area. The metal core includes two mechanical anchoring zones, positioned in the vicinity of its ends, on both sides of the main body.