Abstract: A transverse beam for roof loads on a motor vehicle which is equipped with roof rails. A holding element on each end region of the transverse beam comprises two clamping jaws which can be drawn toward each other by a tightening member. The jaws are clamped to the spars of the roof rails in order to prevent shifting of the transverse beam along the spars upon strong acceleration or deceleration. A recess in at least one clamping jaw. At least one friction brake arranged in the recess, which is supported against the spar. The brake comprises a molded body, e.g. of hard rubber or of wear resistant tough plastic material. The bottom surface of the recess is obliquely inclined to cause the brake body to securely engage the spar as the beam and the vehicle accelerates in the direction of reduced height of the recess.