It can be a puzzle to carry some bikes on existing hitch- and trunk-mounted racks – mainly because most racks rely on your bike having a straight tube from the handlebars to the seat. If your bike doesn’t have that (many kids’ bikes ladies bikes and some mountain bikes don’t) the Advantage Top Tube Adapter solves your problems instantly. The Top Tube Adapter attaches easily between your handlebars and seat with rubber-coated hooks providing a stable perch for your existing rack to support almost any bike. The telescoping bar fits a variety of bike sizes and will not scratch your bike s finish.