Tubular tyre
Tubular ( Switzerland: Collé or Tubolare ) are a type of bicycle tire, in which, is sewn in contrast to the commonly used wire tire tire casing to a closed shell, inside which the actual tube of rubber or latex is. Tubular tires are used mainly in cycling, in cross-country races in track cycling, as well as indoor sports disciplines ( artistic cycling, cycle ball, bicycle polo and for example in wheelchair basketball ) is used. Prepared for the road tubulars are offered with widths from 18 to 25 mm, the mass of between 140 and 300 grams.
Construction
The mantle of a tubular tire consists of two to three layers of a rubberized nylon fabric or cotton, of the carcass on the running surface made rough by a rubber pad, to the protector, often reinforced by one or two strips of fabric below it. On the inside of the jacket is sewn. This seam is protected with a thin, glued textile seam tape.
Installation and repair
Tubular need rims that hold ( the rim ) has a concave outer surface, but no rim flanges. Tubular rims are extremely light and stable constructed. Until the 1950s rims were often spreads from hickory wood, although they were lighter than former aluminum wheels, which are often based on a wooden core, but complex was limited in production and kept wet. Recently found wooden rims still in track bikes and road racing in some mountain stages use. Modern wheels made of carbon fiber are usually constructed as a tubular rims, which has led to a renaissance of tubular tires.
In order to keep tubular tires on the rim, they have to be glued on. Especially in track cycling, an adhesive was added previously often used on shellac base, now used to viscous adhesive ( the cyclist lingo called " Rim " ), or rim tape.
In case of breakdown of the tire is first drawn from the rim. Often adhering to the rim Rim sticks yet sufficiently so that the spare tire only needs to be pressed and inflated on the rim.
If not should uo the rim by means of sandpaper Gasoline are completely free of adhesive residue and dirt. Then, depending on the adhesive a, partly several layers of adhesive applied with a brush. Finally, the slightly inflated tubular tire is also wetted on its seam sealing with glue and clamped as possible without twisting to the rim.
Pros and Cons - Alternatives
The main advantages are lower weight and lower rolling resistance. By eliminating the required in clincher rim flanges also significantly lighter rims are possible, for example, full carbon. The lower rolling resistance is mainly due to the high air pressure up to 15 bar in the track cycling, which is possible by the design of the tubular tire.
In the promise of cross- port makes use of the structural advantages of tubular tires to (partly only 2.5 bar ) to achieve enhanced traction on soft ground with very low air pressure. Another advantage is that tubular tires with pressure loss can not come off the rim, which reduces the risk of a fall.
The disadvantage is the significantly greater time and cost needed for a flat tire. The tubular tire must be released from the rim and glued a new one. The repair of the hose is not provided, but in principle possible by separating the tires and zunäht again after tube repair, but this is only possible with some practice. For this reason, tubular tires are almost only found in professional cycling. Another disadvantage is that the adhesive at very high temperatures ( for example, by the brakes on long descents, especially with aluminum wheels ) are soft and therefore the tire can come off the rim. Then the valve can break off, or the tire bounces off the rim. The cyclist Joseba Beloki this happened during the ninth stage of the Tour de France in 2003, when the tire jumped off the rear wheel and Beloki therefore difficult crashed.
Since the 1980s, there are also narrow clinchers, which in combination with rims and latex tubes offer similar driving characteristics such as tubular tires.