An article transport assembly which is particularly designed for the conveyance of articles such as printing products, and which comprises a guide rail, and a plurality of article transport devices mounted for movement along the guide rail. Each transport device comprises a U-shaped transport body having a base leg and the two upright side legs, and with a gripper for engaging a printing product attached to the base leg. The two side legs each mount a pair of guide rail engaging members, with the two pairs of guide rail engaging members being positioned to engage both sides of the guide rail at two longitudinally spaced apart locations, and so as to permit the guide rail engaging members to move along the guide rail essentially free of play.