Tyre for a vehicle, comprising: • a tread which is intended to come into contact with the ground via a tread surface, • the tread surface comprising grooves, the grooves forming a space opening onto the tread surface and being delimited by at least two main lateral faces (241, 242) connected by a bottom face, • at least one groove being substantially circumferential, being referred to as a circumferential groove, having a width W, defined by the distance between the two lateral faces (241, 242), at least equal to 5 mm, and a depth D, defined by the maximum radial distance between the tread surface and the bottom face, at least equal to 4 mm, • at least one rib, • the tyre further comprising a crown reinforcement radially on the inside of the tread, and comprising a working reinforcement, • the working reinforcement comprising at least one working layer (41, 42), said at least one working layer (41, 42) comprising a radially outermost working layer, • the radially outermost working layer extending radially from a radially inner surface to a radially outer surface, • the radially outermost working layer comprising reinforcing elements which are continuous from one axially outer edge of the working layer to the opposite axially outer edge, at least partially made of metal coated in an elastomer material, mutually parallel and which with the circumferential direction (XX') of the tyre form an oriented angle the absolute value of which is at least equal to 15° and at most equal to 50°, the radially outermost working layer comprising at least one undulation in line with a rib, the at least one undulation in the radially outermost working layer being such that the working layer portion of the undulation is radially on the outside of the points of the working layer that are in line with the centre of the bottom face of the circumferential groove closest to the said undulation, characterized in that the at least one undulation in the radially outermost working layer is such that, in line with the rib on the tread surface comprising an undulation, the minimum radial distance (do), between the radially outer surface of the radially outermost working layer and the tread surface, is at least 1 mm less than the radial distance (dc) between the radially outer surface of the radially outermost working layer and the tread surface, which is the distance in line with the circumferential groove closest to the undulation concerned, and in that the minimum radial distance (du) between the radially outer surface of the radially outermost layer of the crown reinforcement and the tread surface is at most equal to the depth D of the closest circumferential groove, increased by 2 mm. • a tread which is intended to come into contact with the ground via a tread surface, • the tread surface comprising grooves, the grooves forming a space opening onto the tread surface and being delimited by at least two main lateral faces (241, 242) connected by a bottom face, • at least one groove being substantially circumferential, being referred to as a circumferential groove, having a width W, defined by the distance between the two lateral faces (241, 242), at least equal to 5 mm, and a depth D, defined by the maximum radial distance between the tread surface and the bottom face, at least equal to 4 mm, • at least one rib, • the tyre further comprising a crown reinforcement radially on the inside of the tread, and comprising a working reinforcement, • the working reinforcement comprising at least one working layer (41, 42), said at least one working layer (41, 42) comprising a radially outermost working layer, • the radially outermost working layer extending radially from a radially inner surface to a radially outer surface, • the radially outermost working layer comprising reinforcing elements which are continuous from one axially outer edge of the working layer to the opposite axially outer edge, at least partially made of metal coated in an elastomer material, mutually parallel and which with the circumferential direction (XX') of the tyre form an oriented angle the absolute value of which is at least equal to 15° and at most equal to 50°,