An elongated, plate-like structure on which bicycle accessories can be mounted, that is held in place at one end of a bicycle's rear wheel axle or, alternately, ids axial skewer. The latter, like the rear wheel axle, includes bolt threads for threadedly engaging a nut at said end. Supported on either the bike's right or left side, the structure, which extends both perpendicularly to and rearwardly from the rear wheel's rotational axis, defines multiple through openings. Among them is a round aperture sized to slideably receive the rear wheel axle or, alternately, just a part of the skewer-engageable nut at the same time the nut's annular shoulder abuts the structure's outer face. Distal from the round aperture, the structure's generally flat inner face defines a small protuberance which, in use, restrains, from sideways slippage, a bicycle tow leash clamped onto an opening-free portion of the structure's midsection.