<P> UST or Universal System Tubeless is a US patent 6257676 rim designed by Mavic with hooked edges designed to seal with specially designed tires . Several companies such as Michelin and Hutchinson make tires compatible with UST rims . UST was the first tubeless system for bicycles . Other companies such as Stans Notubes Bontrager, DT Swiss, and WTB have their own similar system called Tubeless Ready . </P> <P> In 2006, Shimano and Hutchinson introduced a tubeless system for road bicycles . Tubeless tires have not yet gained popular acceptance in road racing due to lack of sponsorship, the tradition of using tubular tires and the fact that, even without the innertube, the combined weight of tubeless rims and tires is more than top - of - the - line tubular tire wheelsets . Road tubeless is gaining popularity among riders for whom the benefits are worth the costs . </P>

Where does a tire seal on a rim