Single Tube
An obsolete type of tubeless tire. Similar to a
tubular, but made like a loop of garden hose. They were held on to
wooden rims by shellac. This type of tire was obsolete by the end of the 1920's. The most common size was 28 x 1 1/2. A flat could only be repaired by inserting a plug from the outside; damage to the fabric required professional repair in a bicycle shop.
The rim diameter is about the same as standard
tubulars , though few tubulars are as wide as the typical single tube. Reportedly, however, tubulars can be mounted on singletube rims. I haven't actually tried it, can't guarantee that it will work.
Single-tube tires were forced on the U.S. market by a monopoly that excluded the better European clincher tires. Because single-tube tires were so difficult to repair, they drastically reduced the appeal of bicycling in the USA -- as is clear from a comparison of levels of bicycle use in the USA and Canada, where good European tires were available.