Abstract: A plastic platform constructed to be snapped onto a carrier rack of the type which is mounted over the front or rear wheel of a bicycle. The platform serves as a support to prevent articles from falling through the rack onto the rear tire, and also as a fender to protect the articles, as well as the back of the rider, from water and mud sprays. The platform is scored so that its end portion may be bent up to follow the contour of the carrier rack. The platform may be mounted with different orientations as dictated by the type of the rack. Moreover, the platform has slots which not only serve to receive the supporting straps and bungie cords of bags and panniers, but which also serve to permit the platform to be strapped onto carrier racks which are of inappropriate sizes and/or shapes to enable the platform to be snapped thereon.