Attach a GoPro housing (the type with hinge plates) to a Topeak Explorer bicycle rack. The 3-hole pattern of the Explorer rack has been carefully tailored. Any Topeak sliding trunk bag will clear above with the GoPro installed, while any tire will clear below due to a greater diametrical clearance from the axis than that of the bottom of rack. GoPro can also pivot a wide arc. June 2015 version2 stronger.Best to print in a strong material like polycarbonate. Heat the acorn nut (reuse from the GoPro base) before inserting. Use three #8 x 1/2" screws as shown. The plastic holes act like nylon lock nuts.