Home  Down in the PIT / Repairs Featured Tech Articles Re-Gluing Tubular Tires
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Written by Alan Starrett (Big Al)
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Thursday, 30 August 2007 |
Re-Gluing Tubular Cyclocross Tires
OR "Tape and Glue Redux - The Belgian Method Re-visited"
A lot of people must have taken the plunge into the tubular side of the pool since I first published my article on gluing cyclocross tubulars a while back becuase I have started to get a lot of questions on how to glue up a fresh set of tires on previously glued wheels. The good news is that it is actually pretty easy and despite what intuition may tell you a previously glued wheel will probablly end up with a stronger bond in the end.
One thing to address here is why you are re-gluing. The obvious reason is that the old tire is damaged or just plain worn out and you need to install a new one. The next reason might be the notion that you need to re-glue your used tubulars every season or at some other prescribed time interval. I am more of a "If it ain't broke, don't fix it." guy so I don't really subscribe to this theory, especially if you use the tape and glue method. A proper tape and glue job should outlast the life of the tire even in the worst of conditions. Even a good traditional glue job can last a couple seasons if it is taken care of properly. This is why I highly suggest that once you decide to go with tubulars for cyclocross that you commit those wheels to that purpose. Tyring to switch tires out between seasons will be a huge headache.
I check the strength of the glue bond to determine if they need to be re-glued before tire replacement. Deflate the tire down to about 10 or 20 psi. Grasp the tire and rim with both hands and place your thumbs on the sidewall of the tire. Squeeze your thumbs into the sidewall of the tire and watch the joint of the rim and the tire. Repeat this in several spots around the circumference of the wheel. If the glue bond at the edge of the rim starts to fracture away from the tire all the way around the wheel you are due for a new glue job. If the bond is gone before you even squeeze it and there is contamination in the joint you are overdue for a new glue job. If the bond is good at the joint then leave well enough alone, why cause extra work for yourself?
If you need to re-glue a used tire or install a new tire the first step is to get the old tire off if it hasn't been removed already. With a traditional glue job I deflate the tire and grasp it in the same manner that I do to check the bond except in this case I just keep on pushing until the bond is completely broken all around the circumference of the wheel on both sides. After that you should be able to pull the tire right off. With a tape and glue job I first try to break the bond in the same manner desribed previously but chances are if it was done right this won't do much but make your thumbs sore. Typically it takes some sort of mechanical advantage to get the tire off. You can try getting a tire lever between the tire and the rim and start to peel it off. I have also heard of someone actually cutting down through tire down to the rim in order to get a grip on it and peel it like a bannana. If you choose this method make sure you don't ever plan on using the old tire again. Whatever method you choose take care not to damage the rim, it is easier and cheaper to replace the tire than a rim or worse yet a whole wheel.
 | | Old glue - A little rough but clean |
So now that you have the tire off you should be left with a rim that has some old glue left on it. If it was a tape and glue job most of the tape should have come off with the tire. If there is some tape left on the rim you need to pull that off. Now glue that is left on the rim is fine to be left right on there unless it is contaminated or there is a large buildup. If the old glue is grey or black it is contaminated with brake dust, dirt or both. If there are just a few spots that are contaminated don't sweat it. If most or all of the old glue is contaminated you will probablly want to clean it off and start fresh. I won't kid you here, completely cleaning off old glue is hard work. You need some heavy duty solvent, a well ventilated area, gloves, rags and a lot of elbow grease.
 | | Option 1 - Bench grinder |
If you are lucky enough to have mostly clean old glue, your job is a lot easier. It will be fairly rough and a little nasty looking. Don't worry about that though, if the glue is still there after all the yanking and pulling of getting the tire off it is bonded on there well and makes a great base for the new glue and or tape. Since the weaker glue came off with the tire there will be high spots and low spots in the glue.  | | Option 2 - Wire wheel for an electric drill |
To smooth it out a bit I like to use a wire wheel on a bench grinder or in the abscence of that a wire wheel in a hand drill. Just work the wire wheel back and forth across the bed of the rim around the circumference. The old glue doesn't move easliy but as you gently warm it up with the friction of the wire wheel you can spread it a little bit like stiff putty. Be careful not to press the wire wheel too hard into the glue because it will cease to spread and will just start clumping. It also will lodge wire strands into the glue and you don't want that.
 | | Old glue - new look |
If you are re-installing a previously glued tire it is time for a gut check. The base tape on a tubular tire cannot be cleaned nor can you remove or smooth out a significant buildup of old glue. If there is just a small buildup of glue and it is mostly clean it should be fine to reuse. If it is a large buildup of glue or tape or worse it is largely contaminated you have make a decision. If the tire is more than halfway through its life cycle it might be time to cut your losses and just replace it.  | | Fresh (thin) coat of glue over smoothed old glue |
If the tire has a lot of life left in it, it may be worth it to you to have the base tape replaced. There is company called Tire Alert that can install new base tape for $8 per tire. They can also re-tube a tubular tire for $20. That includes new base tape and return shipping. A bargin indeed if you are dropping upwards of $100 or more for a cyclocross tubular.
 | | Tufo Standard Tape |
From this point on you are ready to glue up your tubulars in the method I describe in my previous article on gluing cyclocross tubulars. I have an addendum to that original article however. Namely in the tape used. In the first article I used the Tufo Extreme Tape. The plus side of the Tufo Extreme Tape is that it is super easy to install. The down side is that it is pretty thin and more prone to contamination in wet conditions. We were blessed (cursed?) with an uncommonly dry cross season here in New England last year but typically there is at least part of the season that is a slog fest. In successive wet races I have noticed premature seperation of the Tufo Extreme Tape. I now always recommend using the Tufo Standard Tape. The Tufo Standard Tape is a little harder to work with but when done right it is downright bulletproof.
 | | Wax backing paper |
The Tufo Standard Tape is thicker and more pliable. Basically the "activated strip" that does most of the work on the Tufo Extreme Tape is the entire width and thickness of the Tufo Standard Tape. This makes it super sticky and creates a very flexible joint. Perfect for the stress of a cyclocross tubular. Beacuse of this stickness though it makes it a bit harder to work with. It also comes with backing paper (foil) on only one side. The backing paper is basically wax paper and tears easily which also makes it harder to work with than the Tufo Extreme Tape. Stick with it though (no pun intended), the results are worth it.
 | | Sticky side down first |
When you get to the part in my instuctions on installing the tape do it with the Tufo Standard Tape this way. Install the tape on the rim, white side down, with the backing paper facing up. DON'T TAKE OFF THE BACKING PAPER! If you do you will have a big mess trying to get the tire on. When putting the light coat of new glue on the rim beneath the tape some of it probablly got on to the braking surface. I take a rag wetted out with solvent to clean any of this glue residue off. The backing paper helps keep the solvent from getting on the gluing tape. Removing the glue residue prevents the tire from sticking to the brake surface and peeling up the backing paper when installing the tire. Now install the tire as described in my gluing cyclocross tubulars article.
 | | Patience pays off |
When you get to the part about removing the backing paper is where is gets harder with the Tufo Standard Tape. The backing paper (foil) on the Tufo Extreme Tape is pretty strong and can be pulled from between the rim and the tire with a decent amount of force. The wax backing paper on the Tufo Standard Tape will just rip. What I do after the tire is centered on the rim is to hold the wheel between my legs and lift a small section off the tire straight up off the rim while simultaneously slipping the backing tape out. I work my way around the wheel a few inches at a time, carefully removing the backing paper. When you get that done you are out of the woods and have yourself a crazy good glue job. After inflating the tire and setting it well, let it sit for a little while. In a few hours you should see a tiny bead of the white glue peaking out of the joint between the tire and the rim. When you see this you know that the tape has compressed and is completely bonded across the entire width of the rim bed. Now you are ready to thrash on it. |
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Last Updated ( Thursday, 30 August 2007 )
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; "Old glue - A little rough but clean")
; "Option 1 - Bench grinder")
; "Option 2 - Wire wheel for an electric drill")
; "Old glue - new look")
 coat of glue over smoothed old glue ',500,375,0,0); "Fresh (thin) coat of glue over smoothed old glue")
; "Tufo Standard Tape"){kind=small}
; "Wax backing paper")
; "Sticky side down first")
; "Patience pays off")
