In place of the tube in a normal tyre, the tyre and the rim of the wheel form an air container in a tubeless tyre. To 'seal in the air', in this tyre-rim compartment, the inner wall of the tyre is throughly lined with an impermeable, air-tight membrane. The inner liner of the tubeless tyre is constructed of halo-butyl/chlorobutyl and other materials. This performs, in essence, the important chore of substantially reducing the permeation of air, as compared to the natural rubber inner liner, a function of which is why we use a butyl tube in a tubed tyre.
The main difference between the tube type tyre and the tubeless tire is that the tubeless tire is itself the tube.
Source: justsamachar.comAdded: 2 July 2007