The Basics
Tubular tyres look just like a regular clincher tyre from twenty paces, but the differences are dramatic in the internal construction. Starting with the tyre itself, a clincher tyre looks much like a car tyre off of its rim, in that it is made up of two beads that are formed around a wire hoop or a kevlar strand. These two beads are the foundation for the casing of the tyre upon which a tread has been bonded (usually black tread on a brown casing). The two beads rest inside a deep groove at the centre of a wheel's rim. The edges of today's grooves have a special seating or "hook" to aid in holding the bead of the tyre in place at high pressure. The hook is a recent addition to the straight walls of rims of years past. Some older bikes still use a straight wall and need special attention during installation to prevent blow outs. Inside the clincher tyre, in the groove of the rim is an inner tube that seals a cushion of air inside to allow for a smooth Ride.

A tubular tyre or sew up tyre has an inner tube inside of a casing that has a tread bonded to it also. But this is where the similarities stop. Instead of having two beads that hook into a rim, the tubular tyre has both edges of the casing sewn together to form a continuous donut like shape that houses the inner tube. The thread that has been sewn to hold together the casing edges are about as thick as dental floss and are stitched into the casing about every eighth inch. Covering the threads is a glued down base tape to prevent foreign matter from getting into the casing and puncturing the inner tube. The rim for a tubular tyre has a groove in it but this groove is only about one eighth of an inch deep. How does the tyre stay seated on the rim? It is glued on with special contact cement.

Installing The Tubular Tyre
Installing a tubular tyre is a time consuming and sometimes messy undertaking. Tubular tyres are just big enough in circumference to fit onto their rims. This is so that the tyre will bond tightly to the rim. The glue used to hold down the tyre is a special contact cement that will bond to cloth and aluminium without breaking down the existing glue and rubber that was used to make the tubular tyre. By pre stretching the tyre and putting a thin and even layer of glue on the rim and then an even and thin layer of glue on the underside of the tyre, letting the glue become tacky, and then putting a small amount of fresh glue on the rim for positioning purposes, you can install a tubular tyre in 15 to 25 minutes.

Repairing a Tubular Tyre
What do you do if you get a flat on a ride when using tubular tyres? If you have a spare tubular tyre, you will remove the old tyre by pulling it off (if possible) or by prying it off with a tyre lever or screwdriver (if the glue is extra strong). Then you install the spare tyre and ride home very carefully, especially in the corners so as not to roll the tubular tyre off of the rim.

Repair Work is best done back at home as it's an involved process. First locate the puncture by submerging the tyre in water like you woudl an inner tube. Once the puncher is found then it's a matter of removing the backing tape to expose the casing stitches.  Cut the threads for about 6cm, remove the inner tube, patch it, put the tube back into the tyre, carefully sew back together the casing without puncturing the inner tube, glue down the base tape, then glue the tyre back onto the rim then wait a full 12 hours before riding on the wheel again.

So Why Bother with Tubular Tyres?
Even though they are difficult to install and difficult to repair, tubular tyres have their benefits.

Weight:
Tubular tyres will always be lighter than clincher tyres. Tubular tyres have no penalty in weight from beads made of wire or kevlar since they are one continuous tube in a hoop. The rims used for tubular tyres are also lighter by virtue of design. The cross section of a tubular tyre rim is a box shape with walls that can be made very thin as opposed to the clincher rim cross section that needs to be made much thicker to be strong enough for the loads imposed by the clincher tyre. A tubular set of wheels will accelerate and climb hills with less effort than a set of clincher wheels.

Smooth Ride:
Because of the materials used to make tubular tyres the ride is very smooth and resilient. Most tubular tyres use a very thin tube. Often latex is used to save weight. The thin tube is then combined with a rubberized casing made of high quality cotton. For a lighter tubular silk is used by they have mainly been dropped from production runs due to the inability to get consistant quality in the silk.

Control:
In addition to the control from lighter weight and smoother ride, if you puncture, a tubular tyre is more stable to ride on flat than a flat clincher tyre. This is due to the shape of the box rim of a tubular tyre. Instead of rolling around on the two ice skate like rails of a clincher rim with rubber folding underneath it, you have a flat rim section with rubber being distributed under it evenly.

Can I Get Tubular Tyres For My Mountain Bike?
In the early 1990's, Vittoria (an Italian tyre maker) made tubular mountain bike tyres for a short time. Due to a lack of popularity and limited tread choices, they were discontinued. Current high performance mountain bike tyre technology is leaning toward tubeless designs. It is possible and still popular to get and use tubular cyclo cross tyres. Maybe as mountain bikers move toward lighter and lighter wheels the tubular mountain bike tyre will be reintroduced.

Content for this article was sourced from: http://www.athenscyclepath.com/wconntubulartires.html