In a spinning preparation machine, a machine element lies opposite the clothing of a roller, bearing surfaces of end portions of the machine element are in engagement with respective bearing surfaces of stationary bearings, and an adjustment means is arranged in the region of each of the end portions and the bearings, the adjustment means being able to alter the radial spacing between the roller and the machine element. To enable the carding nip to be adapted or kept constant, adjusting elements of the machine element and adjusting elements of the bearings each have inclined bearing surfaces, and the machine element, in the event of undergoing thermally induced expansion in its longitudinal direction, is so displaceable along the inclined surfaces that the radial spacing remains the same.