Abstract: A conditioning apparatus is provided for working of an upper surface layer of a dirt race track to form a cushion of loosened and uncompacted earth particles. The apparatus includes a rigid structural frame mounted on a single elongated supporting roller extending substantially the entire width of the apparatus. A plurality of transversely extending beams are fixedly secured to the frame and each carries a plurality of vertically extending earth working tines. The frame is vertically adjustable on the roller to a selected elevation and a leveling mechanism is interconnected between the frame and a towing bar to enable pivoting of the frame about the single roller to a horizontal plane when the towing bar is connected to a towing vehicle.