https://www.walmart.com/ip/Allen-…r/10812004

[i]The Allen Sports Bicycle Adapter Bar lets you transform bikes with non-conventional frames. It has a simple design that lets you attach it to any style with ease, creating a top tube. Appropriate for bicycles with a distance of 16" to 27" between seat post and stem, this Allen tension bar has plastic-coated hooks that protect the finish of your bike. Its internal spring makes it a breeze to put on and remove. This bicycle cross bar helps you transport your ride on a carrier if needed. It holds fast once you have your bike in place. The Allen tension bar allows you to put step-through bikes onto a car rack, which typically only holds models designed with a top tube. It also works well for transporting mountain bikes with thick frames that otherwise do not fit hitch-mounted carriers. Quick to install and sturdy as a support, the bicycle cross bar lets you conveniently use an existing rack or acquire one in the style you prefer.