The Saris Bike Beam is designed to bridge the gap between the bike's steam and seat to create a virtual top tube. By bridging the gap between the bike's stem and seat tube, the Bike Beam creates a virtual top tube that lets you bring any bike along for the ride. This beam is easy to use, the sliding collar feature ensures that your Bike Beam is securely installed on your bicycle. It is designed to use with racks where bikes are secured by the top tube, such as hanging style hitch racks, trunk racks or home bike storage solutions. It adjusts to fit most bikes and opens easily with a slide mechanism. The Saris Bike Beam will help you take full advantage of your favorite rack!