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Tips for Attaching Tubular Tires

by David Teall

Twenty years ago tubular tires were the unquestioned performance choice. Today manufacturers have developed and effectively marketed a clincher tire for everyone, and tubular, or sew-up tires, have been relegated to a small niche in the consumer market. Woefully this is so. What has caused this diehard traditionalist to build clincher wheels is the quality of today’s low-cost tubular and the cost of today’s quality tubular. You’ve probably heard one or more pneumatic purists curse about some lump, hump, or bump in his tubular. I too have felt the thump. Even so, there is a certain feel that one can only find astride a pair of good tubular tires. But let’s put the pros and cons aside. This exposition considers the art of attaching tubular tires on the rim.

Before you open that tube of rim cement, inspect the tire’s base tape. The base tape is that strip of fabric that is bonded (I use this word, in reference to cheap tubulars, loosely) to the tubular directly over the stitching. It protects the stitching and the casing, and it is the surface where cement and rim to the tire connect. A poorly bonded tubular base tape is as dangerous as an improperly fastened tire. If you can peel at a base tape with your fingernail and separate it from the casing, don’t by it, not at any price. If you’re stuck with such a lemon, you can either remove the base tape completely and apply cement directly to the casingundefinedstitching and all, or remove and re-cement the tape. If you choose the latter, use 3M Fast Tack (more about this stuff later).

The next step is to stretch the tubular by fitting it on a CLEAN rim. If you’ve been cycling for twenty-some years, then you have a collection of trashed Fiamme Red Labels on which to stretch your "green" tubulars. But you must clean off those layers of old cement, otherwise you’ll have crusty specks of it stuck to your new tubular, and that’ll compromise the bond when you go to permanently mount it. Start by fixing the valve stem in the rim stem hole. Fit the tubular on the rim, working equally on each side of the stem. Stretching the final quarter of the tubular over the rim will probably be tight. Sit down on a bench, hold the rim with the tip of your toes on either side of the valve, and pull the rest of the tubular over the rim. It might be too tight to stretch over the rim, in which case you’ll need to pre-stretch the tubular. I saw Roger Young do this once to a 50-dollar track tire. He hooked the inside with one foot and pulled up with both hands. Then he slid the tire around about one quarter of its circumference and repeated this all the way around. Then the tire was ready for the rim. 

Once you have the tire stretched on the rim, carefully align it. Make certain that the valve stem is straight and that the tread pattern runs centered around the rim. Then inflate the tire to its recommended maximum. Inspect for obvious defects. The bike shop is less likely to accept a return on a tubular that’s been glued. If you have the time, leave your new tire stretched and inflated overnight. The ideal situation is to store your tubular stretched on a rim and slightly inflated (30-40 psi) until it’s ready for use. Some say that slightly aged tubular tires are best; they’re more supple. In the old days, we’d buy a season’s supply in advance and have them all stretched, ready, and waiting on old rims. Gary Dauer, after a roller race in his garage, once showed us what looked like a coat closet. There were, however, no coats inside-- nothing but tubulars--the bare rims skewered by the closet rod. It smelled--like tubulars--a tubular humidor. Mark Tyson pulled a Clement Strata 66 to his nose and inhaled slowly. He closed his eyes, hesitant to exhale. He finally did again breathe, then he slowly opened his eyes and said, "Nice." 

Now that your tubular is stretched and ready, it’s time to give some attention to your wheel. If your rim is brand new, you’ll need to remove any excess oil from the manufacturing process. Use what ever solvent the manufacture of the glue you plan to use recommends for surface prep. If the surface of the rim is smooth, I like to score it up with an awl. Some think I’m crazy for tatooing texture into the concave of a brand new rim. They believe that the glue will adhere to a factory smooth surface just as well as my gnarled. But Skiver showed me this trick back when he and I were getting wheels together for a season on the board track, and I’ve stuck with it since. In any event, whether you scar or go smooth, you must put an initial coat of glue on a virgin rim. 

Which glue to use? That all depends. If you’re just starting out, use a natural base product like Tubasti or Clement, or a synthetic with similar properties like Panaracer. These products require more time to set, but they will allow you time to properly adjust the fit of your tire before it sets. You can also remove without damage and reuse a tire once it has been mounted. Some natural base products, like Tubasti, require mixing. You must really shake, knead, shake, knead, and shake a tube of Tubasti well, otherwise you’ll get runny clear stuff coming out at first and snotty off-white stuff coming out at the end of the tube. The longer the Tubasti tube sits, the longer you’ll have to mix it up. If you’ve mixed it and it still comes out runny, stick a clean bamboo skewer inside the tube and stir, pull that really viscous stuff up from the bottom and work it all in. Clement red and Panaracer (if you can find ‘em) do not require mixing. 3M Fast Tack Trim, a product primarily used for attaching automotive trim fabric to painted or bare metal, is strong, clear, and you can race on it in an hour, but you better line the tread up perfectly the first time. And don’t plan to remove that tire and reuse itundefinedeven as a spare.

To avoid contamination, you should use the same adhesive throughout the life of your rim, so availability has to be a consideration. You can get 3M Fast Tack at most automotive superstores, but the availability of traditional rim cements seems to ebb and flow. Talk to your bike shop manager about the availability of the rim cement he carries or stock up.

The initial coat of cement must be thin and even. If it pools up in the center of the rim, it’s too thick. With practice, you can apply such a coat right out of the tube. Have a plastic sandwich bag handy. If you add too much to a spot you can stick your finger in the corner of the bag and smooth it out. You don’t want to get this stuff anywhere other than the contact surfaceundefinedespecially not on the braking surface of the rim. Once you have applied the initial coat, let it dry, an hour if you’re using Fast Tack, overnight you’re using a rim cement.

Now that the initial coat of cement is on your rim, you can remove your tubular from its stretcher rim and apply a very thin coat of cement to its base tape. Inflate the tire to 60 or so psi. The tire will tend to curl inside out; this is good. Apply an extremely thin coat of cement on the base tape slightly wider than the approximate width of the rim on which you’ll later mount the tire, 22mm or so. Have another plastic bag or two handy in case you need to smooth it out. Start on one side of the valve and work your way around. You can hold on to the valve stem while applying the last stretch of cement to the base tape. Then set the curled up tire on a peg somewhere out of the way to dry, again, overnight if you’re using rim cement, an hour for Fast Tack.

With the initial coats of cement set on the rim and tire, it’s time for the final coat and the mounting of the tubular. This coat should be applied to the rim slightly thicker that the initial coat. Experience will best show you exactly how much. When you later stress the mounted tire and see globules of cement squeeze out, you’ll know you put on too much. If you don’t see any excess cement, you’ll have to wonder whether you’ve used enough. Set the wheel down somewhere it will lie without resting on the rim. I like to have a large coffee can handy and set the hub inside the can so the wheel rests on its spokes. A bucket will do. Now grab that tire off the peg and release the pressure until it just holds its shape. Hold the rubber of the tire at the valve in one hand and the wheel by its hub in the other and fit the stem in the valve-stem hole. Now it gets tricky. You have to be careful not to touch the cemented surfaces nor allow the cemented surfaces to touch anything else. Fit what you can of the tire on each side of the stem. Then sit down on a bench, stick your feet in the wheel (barefoot’s best), grab hold of the rubber with each hand on opposite sides of the wheel, and alternately fit each side of the tire with both hands. It’s going to be real hard to keep the cemented surfaces away from other surfaces when you get toward the end, but if you have properly stretched the tubular, have a good grip with your toes, and you firmly hold the tire by its rubber with both hands up and away from the side of the rim, you can do it. Once you have the tire cemented on the wheel, starting on either side of the stem, grab the casing by the rubber and lift if away from the rim, twist it slightly back and forth, and set it back in place. Repeat this every four or five inches all the way around. This step assures a proper bond and lets you see where there is adequate cement.

Now you can align the tire tread. For this I like to use a wheel stand. Inflate the tire to 50 or so psi. Then slowly spin the wheel while sighting along the rolling tread. Grab the spot where any whoop-de-do occurs and straighten it out. Quality tubular tires will have a base tape that is centered and parallel to the tread, and you can use the distance between the base tape and the edge of the rim to align the tire. If you’re using Fast Tack you’ll have to align your tire with the base tape and the rim because your tire is pretty much stuck on contact.

The final step is to stress the wheel. Take the wheel out of the stand (be careful not to touch the edge of the rim where cement has slightly run over or oozed out) and inflate to the recommended pressure. Then set the tire on the floor and straddle over it with your feet shoulder length apart. Place both palms on the rubber (again, watch out for cement), and balance as much of your weight over the tire as you can manage for two or three seconds. Repeat this for every four or five inches around the circumference of the wheel. Leave the tire fully inflated for 24 hours if you’re using rim cement or one hour if you’re using 3M Fast Tack. Now you’re ready to take that last corner at Scotch Ridge without touching your brakes, or unleash a vicious attack going into turn three at O.O.I.P., or dive down the banking in turn two of the new velodrome at full speed, or any other such rush-producing activity. And no Mike Walden incarnate will ever roll your tires off with his bare, bear hands.

Author’s note

If I sound adroit, it is because I stand on the shoulders of many. I’ve already mentioned wheelmen Tyson, Dauer, and Skiver, and cycling legends Roger Young and Mike Walden, all of whom imparted some bit of knowledge to me. Here I would like to acknowledge the author of the seminal DD article on cementing tubulars, Mark Loudenslagel. I read and reread Mark’s article over and again when I was a novice. It showed me the basics, all of which I have tried to regurgitate above. Thanks Mark.

 


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