Allen Tension Bar Bicycle Cross-Bar Adaptor for $13.54

Made by Allen Bike Racks, this adaptor bar adds a top tube to your bicycle frame so that it can be installed properly on a bicycle carrier. It's designed to be used with hard-to-mount bike frames, such as full-suspension bikes, women's bikes, or other non-conventional designs. The bar features an internal spring that maintains constant tension to keep your bike secure.