Written by Alan Starrett Wednesday, 16 March 2011 19:08
My two previous articles on the Belgian method for gluing (and re-gluing) tubulars have had thousands of hits so I am assuming they have helped a lot of folks get into using tubulars for cross. It has been a few years since I wrote those articles and there have been some changes in availability of products in my process so I figured it was time to update how I am gluing cross tubulars now.
If you read those articles you already know I am a huge proponent of the tape and glue method of gluing cross tubulars. It is sometimes referred to as the Belgian method because supposedly that is where it originated and there are a large number of Euro pros that use the method or some variant of it. In my experience using tape in conjunction with traditional glue is hands down the strongest way to glue cross tubulars.
My go to gluing tape was always the Tufo Standard Gluing Tape. Unfortunately either Tufo no longer makes the tape or Tufo North America no longer imports it into North America because it is no longer available in the US. Fortunately after some searching I found a suitable replacement, Jantex Tubular Gluing Tape. It is a very similar product to the Tufo Standard Gluing Tape in material. The most noticeable difference is that the Velox is thinner, not narrower mind you, just thinner. Where as I could get away with only one layer of glue on the rim and one on the tire with the Tufo tape I use 3 thin layers each of Mastik One glue on the rim and the tire with the Velox. More on that later.
As with any project it is important to get all your supplies and work area prepared before you start. You are going to be working with some really sticky glue and it is time sensitive so you want all your ducks in a row. The last thing you want is to get halfway through the process and have something trip up your rhythm because you were not prepared. Most importantly be sure to block out plenty of time. The method works best for me to just go straight through the steps so you don't want to shortchange yourself on time and have to stop and start again at a later time. It takes me at about an hour per wheel and I have a lot of practice so if it is your first time you may want to budget and hour and a half per wheel.
Presumably you will already have a wheel and tubular tire or a set of both. Dry mount your tires on the wheels and check to make sure your valve stems clear the rim enough to easily inflate with a pump. If the valve stem doesn't clear you will need an extender. The best extenders are the ones that are semi-permanent and the relocate the position of the valve core. Don't mess with the thread on type that you take on and off. They are a hassle and never hold air well.
Inflate the tires to around 60 psi and let them sit at least overnight and check them in the morning. Most high end tubulars are handmade and like anything handmade there are variances from tire to tire. Check to make sure the tread and base tape is mostly even all the way around and that both are secured well to the casing. Don't go pulling at it, just make sure visually that it isn't peeling up anywhere. Also check to make sure it held air overnight. Most high end tubulars have a lightweight latex tube inside. Latex tubes are more porous than regular butyl tubes so they leak down a lot faster. If the tire is still pretty firm after sitting overnight it is all set. Letting the tires sit overnight also helps stretch them out a little so they are easier to mount. I find handmade tires from folks like Challenge or Dugast are so supple that it isn't imperative to stretch them but since you are letting them sit overnight to check for any defects it doesn't hurt to have them stretched a little.
If you notice any problems with a new tire at this point don't move on. Contact the retailer where you bought the tire and work out getting the tire replaced. Nobody will take back a tubular tire after it has been glued even if it hasn't been ridden. You glue it, you own it, period.
For this article I was using a set of our closeout Vuelta Corsa Super-Lite alloy tubular wheels and a pair of my favorite all around cross tubulars, the 32mm Challenge Grifo.
As previously mentioned I am using the Jantex Tubular Gluing Tape. One roll will do two 700c wheels so if you are only doing one wheel you will have extra for next time.
For glue I use Mastik One from the can. Mastik One is a natural rubber glue so it retains some flexibility longer than other types of glue which is critical for a cross tubular. You can buy tubes of Mastik One but it isn't an exact science how much glue lays down each layer so it is pretty tough to tell you exactly how many tubes it will take to adequately do a wheel. The glue doesn't go bad as long as you seal it back up when you are done so get the can. You know you will have plenty and you have it on hand for the next one you glue. Besides, it ends up being more economical in the long run to buy the can.
To spread the glue I use an acid brush. These are the cheap little brushes with short bristles and the cheesy metal tube handle. Look for them in the plumbing section of the hardware store. They are typically inexpensive so get several. I can usually do a complete wheelset with one brush if I do them both straight through without stopping but it is better to have more than you need and not use them than the reverse.
If you don't have them at home pick up some vinyl work gloves while you are at the hardware store. They are handy to use while you are applying the glue so you don't get it all over your hands. On that subject, a work apron is helpful if you have one. Otherwise make sure you are wearing clothes you are not worried about getting glue on. Even a seasoned gluer can get some glue on themselves sometimes and you don't want to ruin your favorite tee shirt.
I use a little sandpaper to roughen up the rim and alcohol to wipe down the rim. Not a heavy grit sandpaper, just something light to roughen the rim bed. I use denatured alcohol to clean the rim bed after sanding and you can get that at the hardware store as well but if you have some rubbing alcohol around the house that will work too. I like having the denatured alcohol on hand though because there are many things you can use it for when working on bikes.
Have a pair of scissors handy to cut the tubular tape.
If you have a wheel truing stand it is really helpful to have when applying glue to the rim bed. It is not a deal breaker but it could save you some frustration.
I also like to use a consumer grade cone wrench to aid in removing the backing paper after the tire is on the rim. The type of cone wrench that is thin stamped steel with no coating. Any similar flat thin piece of steel will work as long as it is totally clean and free of grease or oil. If you don't have one you can do without but it is harder on your fingers.
Summary of Supplies:
Mastik One Glue - Can
Velox Jantex Belgian Style Tubular Gluing Tape
Vinyl Work Gloves
Work Apron (Optional)
Truing Stand (Optional)
Consumer Cone Wrench (Optional)
Now if you have all your supplies ready to go you need to get your workspace prepared. First off you will be working with volatile adhesive so you want to have a workspace that is well ventilated and free of sparks or flame. You also want your workspace to be clean. Again, you will be working with wet adhesive so if you are working in a dirty area the chances that you get foreign material in your glue is higher. One thing not to overlook is comfort. You will be working on this project for at least a couple hours steady if you are doing a set of wheels so you want to make sure the temperature and your work position is comfortable.
So if you have all your supplies and workspace ready to go along with time blocked out for the project you are ready to go.
I start by roughening up the rim bed a little bit with sandpaper. You are not looking to go crazy here, you just want to knock the gloss off the rim bed and put some micro etching in the surface to give the glue a little better chance of sticking. Now, if you have a carbon rim I do the same thing I am just more cautious to not take off a lot of material. Again, I am just looking to roughen the surface a little but. You can see in the photo above that the rim bed has a little gloss on it from the factory.
After the sanding I wet a paper towel out with the alcohol and thoroughly clean all the dust off the rim bed. If I am doing a wheelset I go ahead and prepare the bed on the second wheel right after I do the first. In the photo you can see how the gloss is gone and the dull surface that is left has some tiny scratches in it that will help hold the glue.
Ok, now it is time to open the can, don the gloves and start slinging some glue. Put the wheel in the truing stand if you have one. Begin at the valve hole and spread the glue on the rim bed working on 3-4 inches at a time making your way around the rim. No need to overload your brush with glue, just wet it out enough to get a thin coat on the small section of rim you are working on. It is a good idea to work somewhat quickly and brush in only one direction. The glue starts to firm up pretty soon so if you work on too large a section it will get really globbed up before you can smooth it out. If you try to brush in both directions the brush can stick on the glue you just smoothed out as it starts do dry. Spread the glue right over the nipple holes. Try to get the glue as even as possible but don't stress if it is a little bit uneven. It isn't like paint, it won't ever be perfectly smooth. Make sure you get the glue all the way out to the edge of the rim bed but try not to get it on the braking surface. If you get some on the braking surface you can wipe it off with your finger quickly before it sets up otherwise just wait until you are done mounting the tires and take it off when it is dry. If you try to take it off while it is setting up it is more likely you will just spread it around and make more of a mess.
If you are doing a set go ahead and repeat the process with the second wheel right after doing the first. Carefully set the first wheel on its side on the floor while you move on the the second wheel. Make sure it isn't someplace you are going to run into it or knock something into it.
Once you have the first layer of glue on the rim(s) move on to the tire(s). Inflate the tire just enough for it to take shape. Set the tire down vertically in front of you and while holding it vertical press down on the tire from above just enough to flatten out the tire where it contacts the surface you are working on. Spreading the glue on a flat section of tire is easier for me than trying to spread it on an interior curve. Starting at the valve stem spread a thin layer of glue on the base tape and work your way around the tire. Again, work only with a few inches at a time. Keep the brush moving and brush in only one direction. You only need to wet out the base tape on this layer but the base tape tends to take more glue on the first layer than it does in subsequent layers. Make sure you spread the glue all the way out to the edge of the base tape but be careful not to get it on the sidewall. As with the rim, if you do get some on the sidewall and you can wipe it off quickly while it is wet go ahead. Don't try to wipe it off with a cloth, it will just stick to the glue and make a mess. Your only real shot is to wipe it off with your finger and the vinyl glove. If you don't get to it in time don't stress about it. It will look better in the long run if you just leave it alone instead of taking drastic measures to try and remove it.
If you are doing a set go ahead and repeat the process on the second tire now. Make sure you set the tire down in a safe place where it won't get disturbed.
After you are done with the first layer of glue on the tire(s) go back to the wheels(s) and apply a second thin layer on the rim(s) in the same manner as described before.
When that is complete move back to the tires(s) and apply a second thin layer as described before.
You can move right along from one step to the next applying glue in this manner. For these first two layers of glue on the rim and tire it only needs to set up for the time it takes to spread the next layers of glue in the sequence.
Now you should have two thin coats of glue on the rim and the tire and we are ready for the third and final coat of glue on the rim. I sometimes refer to this coat as the "mount coat." Apply the third and final thin layer of glue on the rim as previously described.
As soon you are done with that lay down the gluing tape right over the top of the third layer of glue. Start the end of the tape at the middle of the valve hole, backing paper facing up, and press it into the rim bed while working your way around the rim. DON'T TAKE OFF THE BACKING PAPER! Do a few inches at a time keeping the tape snug so it doesn't develop air bubbles beneath it and keep it centered in the rim bed. Use your thumb to press the tape into the rim bed as you go. When you reach the valve hole again use the scissors to cut the tape so the end lines up near the center of the valve hole. Run your fingers or thumb around the entire circumference of the rim pressing the tape down into the glue. I have a rubber mallet with a handle with a perfect curve to fit in the rim bed to help push it down. If you don't have anything like that your fingers work just fine.
If you are doing a wheelset move right on and repeat the process of applying the third layer of glue and gluing tape on the second wheel. Just set the wheel(s) aside and move on to the tires after the tape is mounted.
Apply a third thin "mount coat" of glue to the base tape of the tire in the same manner as described before. If you are doing a set of wheels go right to the second tire as soon as you are done with the first. When you are done with the second tire the first tire should be ready to mount on the rim. If you are doing only one wheel let the tire set for a few minutes until the glue has set up just enough so that when you lightly touch it with your bare finger it doesn't stick. It is at this point that I ditch the vinyl gloves as I like to get a better grip from here on out when mounting the tire.
Ok, so now it is where the rubber hits the road, no pun intended. Up until now we have only been laying on glue and while that can be nerve racking enough if you have never done it before you are at a whole new level of commitment when you start mounting the tire. This is where my style of the Belgian method departs from what other folks do. I leave the gluing tape backing paper on the rim when mounting the tire. It takes a little more work to pull the tape out after the tire is on the rim but it allows you to more easily get the tire on the rim and it is easier to center the tire. Start by peeling the backing paper back a few inches on each side of the valve hole and fold it at 90 degrees. Don't go crazy here just a 2-3 inches either side is fine. Make sure the tire is inflated enough to take shape. Center the valve stem over the valve hole and center the tire on the rim bed then mount the tire on the few inches of exposed gluing tape. Press the tire down firmly into the tape. Now you are ready to mount the rest of the tire.
Completely deflate the tire. Hold the wheel/tire in front of you with the valve stem straight up and down. In each hand grasp the un-mounted section of the tire just to the left and right of the section that is mounted. Hold the un-mounted sections in each hand a little off them rim and while stretching it away and down from the valve stem slide it onto the rim. While keeping tension on the tire work your hands around the tire continuing the stretch the tire away and down from the valve stem while you slide it onto the rim. Make sure you don't disturb the backing paper a you slide the tire on the rim. When you have about 1/4 of the tire left to mount, keep tension on the tire then pull the wheel up into your stomach and balance it on your thighs so you can use your thumbs to stretch the rest of the tire up and onto the rim.
Now you are ready to center the tire. Inflate the tire just enough for it to take shape. You can start centering the tire by using the base tape as an initial guide. Rotate the tire left or right on the rim bed so that base tape is exposed by more or less the same amount on each side all the way around. There may be some glue that seeped out from the under the backing paper and stuck to the base tape on the tire but it isn't a problem, just pull the tire away from the glue. Once the base tape is more or less even spin the wheel in your hands to see if the tread is centered on the rim and tracks mostly straight as it spins. If it doesn't just go back to the sections that are out and center them. As I mentioned before, most high end cross tubulars are handmade and as a result the base tape and tread isn't machine perfect from the get go. There will be slight variances in both so you are trying to get it as good as you can which will never be perfect like a machine made clincher.
Once you have the tire centered and you are happy with it you can take out the backing paper. Completely deflate the tire. Starting from just beyond where the tire is already stuck down near the valve stem, pinch the tire tightly with your fingers and lift it straight up off the rim bed. At this point if you have a cone wrench like I mentioned before you can slip it between the tire and the rim a few inches ahead of where the tire is already stuck down to the gluing tape. Continue to lift the tire away from the rim just enough to gently slide the backing paper from between the tire and the rim up to where the cone wrench is. Be very careful here, the backing paper is fragile and will tear easily if you pull too hard. If the tape isn't coming out easy you have to lift the tire a little more. Carefully set the section of tire down back down where you just removed the backing paper making sure it goes back in the same position from where you lifted it up. Continue advancing around the wheel by lifting tire, moving the cone wrench ahead, pulling the tape out behind it and setting the tire back down on the gluing tape. When you get to the valve stem pull out the cone wrench and the last of the backing paper.
If you don't have a cone wrench or something similar you can do it with just your fingers only but it will require a lot of finger strength and it is a little tougher to keep the tire straight. My method of leaving the backing paper on when mounting the tire may seem harder for some folks but for me I prefer being able to take my time getting the tire on and centering it. If you take the backing paper off before mounting the tire you have to be very adept at getting the tire on the rim one smooth motion and then be extremely quick about making any adjustments to the position of tire. Within moments the tire sticks to the gluing tape so well that if you try to move it much you will have a gooey mess all over.
Once you have the backing paper out, inflate the tire just enough for it to take shape. Spin the wheel in your hands to make sure the tire is still centered. If it is out a little bit at this point you may be able to shift it some but not much. If you are satisfied with it inflate the tire to about 25 psi and compress the tire into the floor for one full revolution to firmly seat the tire on the gluing tape. Inflate the tire to about 60 psi then let it sit overnight and it is ready to ride.
If you want to feel confident about your gluing job in the am take a look at the joint between the tire and the rim. Depending on the tire and the rim you may be able to see a tiny sliver of the white gluing tape and some glue peaking out. Deflate the tire to around 25-30psi and squeeze the sidewall a little near the joint. As the tire just starts to pull away from the rim you should see some gooey tape and glue in the joint stuck to both the tire and rim. If you see this it means you did it right and you have the best glue job you can get.
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