Bicycle Tubular tires are the cycling equivalent of expensive running shoes. So why doesn't everyone use them? The Basics:
Tubular tires look just like a regular clincher tire from twenty paces, but the differences are dramatic in the internal construction.
Starting with the tire itself, a clincher tire looks much like a car tire 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 tire upon which a tread has been bonded (usually black tread on a brown casing). The two beads rest inside a deep groove at the center 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 tire 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 tire, 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 tire or sew up tire 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 tire 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 tire has a groove in it but this groove is only about one eighth of an inch deep. How does the tire stay seated on the rim? It is glued on with special contact cement.
Installing The Tubular Tire:
Installing a tubular tire is a time consuming and sometimes messy undertaking. Tubular tires are just big enough in circumference to fit onto their rims. This is so that the tire will bond tightly to the rim. The glue used to hold down the tire is a special contact cement that will bond to cloth and aluminum without breaking down the existing glue and rubber that was used to make the tubular tire. By pre stretching the tire 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 tire, 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 tire in 15 to 25 minuets. Glue usually finds its way onto your work bench, your floor, your hands, your shoes, your carpet, your hair and your dog. If you want some tips on tubular tire installation email me and I will give you some useful information.
Repairing a Tubular Tire:
What do you do if you get a flat on a ride when using tubular tires? If you have a spare tubular tire, you will remove the old tire by pulling it off (if possible) or by prying it off with a tire lever or screwdriver (if the glue is extra strong). Then you install the spare tire and ride home very carefully, especially in the corners so as not to roll the tubular tire off of the rim.
If you are a hard core survivalist roadie with a permanent wool jersey, chain ring scars on your knees (from the big crash in TOSRV '79') and tan line dots on the back of your hands from your mesh gloves, then you will take out your dental floss, a needle, a knife, a patch kit, and some tubular tire glue. Removing the tire you will find the location of the puncture on the tire by immersing the inflated tire in the nearest ditch with stagnant water and look for bubbles. Upon finding the leak you will pull off the base tape, cut the threads for about two inches, remove the inner tube, patch it, put the tube back into the tire, carefully sew back together the casing without puncturing the inner tube, glue down the base tape, then glue the tire back onto the rim, sleep for an hour in the nearest field, and ride home at first light the following day.
So Why Bother with Tubular Tires?
Even though they are difficult to install and difficult to repair, tubular tires have their benefits.
Tubular tires will always be lighter than clincher tires. Tubular tires 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 tires are also lighter by virtue of design. The cross section of a tubular tire 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 tire. A tubular set of wheels will accelerate and climb hills with less effort than a set of clincher wheels.
Because of the materials used to make tubular tires the ride is very smooth and resilient. Most tubular tires 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 or even better than that, silk. This makes for a rider to road connection over clinchers that feels like the equivalent of taking off army boots walking in a brand new pair of $200 running shoes.
In addition to the control from lighter weight and smoother ride, if you puncture, a tubular tire is more stable to ride on flat than a flat clincher tire. This is due to the shape of the box rim of a tubular tire. 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. This is not a big deal unless you are going around a corner at 28 miles per hour with one hundred, hungry for a pizza gift certificate prime, criterium rats (racers) surrounding you.
Can I Get Tubular Tires For My Mountain Bike?
In the early 1990's, Vittoria (an Italian tire maker) made tubular mountain bike tires for a short time. Due to a lack of popularity and limited tread choices, they were discontinued. Current high performance mountain bike tire technology is leaning toward tubeless designs. It is possible and still popular to get and use tubular cyclo cross tires. Maybe as mountain bikers move toward lighter and lighter wheels the tubular mountain bike tire will be reintroduced.
Should I Stay Away From People That Use Tubular Tires At All Costs?
If the person who has tubular tires is knowledgeable enough to glue on their tires properly, then don't be frightened by the sew up guy or gal. If you shred a clincher tire on a ride you might be able to borrow a tubular tire from someone to put onto your clincher rim to limp back home.......if you haven't made too much fun of the glue in that someone's hair.