A tire comprising a carcass reinforcement (2) surmounted radially on the outside by a crown reinforcement (3), itself radially on the inside of a tread (4) having two axially outermost ends. The crown reinforcement (3) has a layer of reinforcing elements. The tread is connected to two beads (5) by two sidewalls (6), each bead (5) comprising at least one circumferential reinforcing element. Sidewalls (6) comprise, on their exterior surface, a series of protuberances (8) alternating with voids (9). The tread (4) comprises, at least at one axially outermost end (4a), a circumferential groove (10), wherein each protuberance (8) is positioned at the surface of a sidewall, the different protuberances being arranged regularly or irregularly and continuously between a point A and a point E, and wherein at least one protuberance (8) partially or completely interrupts or does not interrupt the circumferential groove (10).