A reinforcement beam is roll formed from a metal sheet for use in a vehicle bumper system. The reinforcement beam includes adjacent tubes having a common center wall and lateral portions extending from opposing sides of the common center wall that are roll formed simultaneously in the same rotational direction to enclose interior volumes of the adjacent tubes and to define top and bottom walls and front and rear wall of the reinforcement beam. The front walls of the adjacent tubes each include a channel rib depressed into the interior volume of the respective adjacent tube longitudinally along the reinforcement beam for stiffening the respective front wall. A weld is formed separately in each of the seams between the front walls and between the rear walls, thereby defining a crevice rib between the channel ribs to improve the bending strength and torsional strength of the reinforcement beam.