Monday, April 20, 2009

How To - Glue a Tubular

Fail!

I did a horrible job gluing this tire. Although the tire had a slow leak that escaped my somewhat hurried overnight pressure test, the wheel would have been unrideable due to the immensely horrible glue job. Note how easily I can peel away the tire? The tire would have rolled off pretty easily.

Having said that, it took about 15 minutes of struggling to start separating the tire from the rim. Once I got the first 10-12 inches freed, the rest of the tire followed in a minute or so.

If you need to glue a tire on a rim, you're in the same situation I'm in now. So let's glue a tire. You have a tubular wheel, and a tubular tire. You need to mate the two. How do you do it?

First off, let's go over some competencies and responsibilities you have as a cyclist. A big one is that you have to take care of your equipment in such a way that your bike does not endanger others. If it endangers yourself, fine, you suffer. But if you endanger others, that's a real big no-no.

A "no-no" example is, say, improperly mounting a tubular tire such that it comes off while you're riding it. Big no-no.

Since tubular tires are not as easy to mount properly as a clincher tire, it's imperative that you do it properly.

(I should point out that mounting a clincher tire improperly will also lead to a tire spontaneously dismounting, and such an event may also cause problems for the rider and those around him. This phenomenon is not reserved for tubular tire users.)

With that thought always at the back of your mind, let's proceed.

Start with dry-mounting a new tire on the rim to stretch it. This means you put the tire on without using any glue.

In my case I stretched it for a while - probably 20 minutes - while I looked for my glue. You're really supposed to stretch your tires at least overnight, and preferably a week. Back in the day I'd get a bunch of tires and let them "age" over the winter - the rubber hardens a bit, making them less likely to puncturing, or so the myth goes.

Now I just mount whatever tire I have, whenever I need to mount it. In this case I've had the tires for a couple months. Not intentionally though. I bought them and told myself I'd glue them "next week". Then suddenly two or three months had passed, I had a race coming up, and I had to glue them like "right now".

Pump up the dry-mounted tires while you're at it - you want to discover any defects in the tires now, not after you've glued it (most stores will exchange a defective non-glued tubular but not any tire with glue on it). Don't go back to the store after 6 months though - if the tire is totally flat in less than a day, it's probably not good, and you should bring it back then.

Keep in mind that latex tubed tubulars (Vittoria CX, for example) will drop to about 40-50 psi overnight. Butyl tubed tubulars (Contis) will retain pressure like a regular clincher.

The "age your tubular" reality is that this is the time you check for defects. Aging the tire is less important. Nonetheless, tradition demands tire aging. So age your tires.

I do notice the tread firms up a bit over the course of 6-12 months of aging. It would make the tire less succeptible to picking up debris and such, and let it wear longer. I think. Whatever, it sort of explains why riders think aging a tire is good.

(Car tires, on the other hand, just get worse when they age. Competitive car drivers will know the manufacturing codes on the tire sidewalls so they can see how old a tire is - and they'll choose the youngest, newest tires possible, given the choice.)

You can also use the "aging" mount to practice tire mounting techniques. Since it's hard to take pictures around wet tubular glue, I took some when I was dry mounting the tire to stretch it.

Note the Pinch Hold.

This is not a special Ninja technique for disabling your victims, although someone demonstrated to me a special defense technique similar to this just the other day (and boy did it hurt). Instead, this is a good way to hold a tire whose basetape is covered in sticky, icky tubular glue.

Pinch and pull up. You'll be surprised at how hard you can pull up on a tubular tire when you have a panic attack because if your fingers slip you'll have glue all over everything that you forgot to cover when you started putting glue on the tire.

If that's how you hold the tire, how do you hold the wheel?

The Toe Grip. Requires either special Ninja Toe shoes or any pair of socks.

This is a particularly useful hold when you can't touch the top of the rim because it's covered in icky, sticky glue. I try to do this on concrete (the glue doesn't really gob off when it's tacky, which is what it should be) or on a piece of cardboard if I'm on the living room rug.

Not that I've ever mounted a tubular tire in the living room. Really.

Once you've mounted the tire, pretending that all the tire-rim touch points are covered in tubular glue (sort of like when you're a kid and you pretend that the stepping stones going to your front door are surrounded by lava, and if you fall off of them you... um, you have pretended that, haven't you?), you can take the tire off and put real glue on both the tire and rim.

As an overview this is what we'll be doing: First, we'll first apply a layer of glue to the tire and the rim. Once both applications are relatively tacky, we'll put a second thin layer on the tire, and a second thin layer on the rim. Then we'll mate the two and hope things are good.

Choose a tire. The good pile is up high, the questionable ones are below. I chose from up high.

Tire and a pump. Note how white the basetape appears.

To put glue on a tire can be tricky. It's hard to glue the inside of a hoop. It's much easier to glue the side of a hoop. Therefore, make the tire into a sideways hoop. How? Pump it up a bit.

No psi. And the tire will be hard to glue, especially the side that's facing the floor.

Hey! I'm a flounder!

The tire is now laying in such a way you can glue the whole base. Flounder-like, if you will. Cool. Takes about 27 psi it seems, according to my floor pump.

This makes things much easier to glue. Note that the tire suddenly got what looks like old glue on it. That's not an illusion - it's actually what happens when you first pump up a tubular. Glue squeezes out of the casing, covering the basetape, and dust and stuff will stick to it, making the tire look kind of old right away.

Okay, that's really not what happened. Heh.

After I looked at the brand new tire, I realized I hadn't pressure tested it. So I mounted it on a wheel I had laying around, pumped it up, and grabbed another tire. I figured a used tire that I just pulled off a good wheel would be fine (because it had been pressure tested, aged, and raced already), and I found one in the upper pile (hanging off the top of the closet doors). The tire came off my short-lived PowerTap wheel, so it got, what, like 20-30 rides on it.

Luckily it was a Vittoria CX, my favorite kind of tubular. Even more fortunate was that the tire had previously been used on the rear, so it had some wear. Since tubulars tend to actually wear out before they get cut or punctured, I try and rotate my rear tires to the front before the flat bit in the middle of the tread gets too wide. A tire with a wide flat spot feels weird as it heels over in a turn. This tire hadn't gotten to that point, so it's an ideal front tire.

You also need glue. Everything else is optional.

I like Conti's glue. I don't like their tires, but their glue works well. It's considered a "clear" glue, one that is translucent. Vittoria has one, so does Panaracer. I've used all of them, and they all seem pretty good. Panaracer seems to have the most solvents, Vittoria seems the thickest and least translucent.

*UPDATE: 2012, I am using Vittoria Mastik One, a clear type glue. I like it enough that I bought a box of it retail from a bike shop.*

Clement, Vittoria, and others have a "red" glue, which looks like oozy bone marrow. Or pureed liver. Something like that. I've used both and I prefer "clear" glues.

Red can get messy just from squeezing out from under a tire. However, I find that red will fill gaps better, it seems like I can use more without feeling like I'm dissolving the tire, and it's what I started using when I was a kid. Red glue takes more time to dry - definitely 24 hours, and preferrably 48-72 hours.

In the above pic, I have a half or 2/3 used tube of glue (the upper one) and a brand new yet-to-be-unsealed tube of Conti cement. The white piece of paper is actually the tag off the tire - it's strong (ripstop plastic-like paper), won't let glue through, and is a good size. It was also right there, a key factor when looking around for a perfect glue-spreading utensil. It looks used because I already used it to glue a few tires. I just lay it on the stand to store it, and it sticks to the stand on its own. Imagine that.

The truing stand is there to hold the wheel. It's possible to glue the tire without one, but virtually impossible to take pictures of oneself gluing said tire. Since I wanted to take pictures, and I had the stand, I used it.

If you have less than a full tube, make sure you have a second one. This especially applies if you have a brand new tire, or, worse, a brand new tire and a brand new rim. You can easily use a full tube of glue in such an instance.

Since cats and tubular glue don't mix well, here's a picture of a cat to satisfy my need to show them off.

This cat got caught up in a bunch of glue.

The vets had to shave it. Make sure that you've secured your gluing area from fuzzy pets, little kids, curious grandparents, and the like. "Gluey", as some named the above cat, has grown her fur back into a nice, dark, almost black color.

Now glue.

If you have any doubts about your clean gluing ability, wear some latex gloves during the process. If you have supreme confidence in your clean gluing ability, you can skip the gloves. And you'll find out for sure exactly how good you really are at gluing cleanly.

With glue, once you open the tube, don't squeeze it! I mean really, don't squeeze it at all. Just tilt it towards the tire and just nudge the end of the tube to encourage the glue to come out. Squeeze it and you'll have glue everywhere. Do a nudge squeeze, one where, if it was toothpaste, you wouldn't see the paste budge, and tubular glue will flow like, well, like toothpaste.

When pausing your gluing to destress and such, prop the glue so the open end is up. Or cap it. Don't let it point downhill because after you shake out your wrist or hit the head or whatever, you'll look at the tube and it'll be in its own puddle of glue.

Trust me, that's what happens.

Start at the valve.

How did you know I'd say that? Always start there so you know where to end. Also you can use the valve to turn the tire.

I find it easier to kneel on the floor (pretend you're looking for contacts on the floor), arc my hand using my elbow as the pivot point, and glue the section my hand arcs over. Then spin the tire a bit so your hand arcs over a different section, and glue that. Repeat until you get to the valve.

On tires, since the basetape's adhesive apparently dissolves from too much tire glue, go sparingly on the glue.

I think this is actually a myth, since folks put a lot of glue on the rim, and when you join the two together, that glue on the rim is now... on the basetape. Ultimately the basetape adhesive will lose grip and the basetape will start to peel. Since this happens after a bit of time, one might deduce that the glue caused it (because it doesn't do that on its own, not for a long, long time). However, it's possible that some other factor, like UV rays, degrades the glue.

Whatever. Tubular tires are part of that superstitious part of cycling, and if the legends claim that too much glue is bad for the basetape, so be it. I put glue on the tire sparingly but with good coverage.

I used that tire hang tag to spread the glue a bit. More consistent coverage, but thin because of the myth.

Now for the rim. I find it easiest to use a truing stand, but failing that, you can glue a rim, carefully, by holding it with one hand and gluing with the other. The latter method tests your clean gluing ability more thoroughly.

I just started this rim. Notice the wet glue. It looks wet even. Much more glue.

You can see the wet glue trickling a bit.

See how the glue is trickling down just to the left of the spoke hole in the middle (lowest of the three close together)? I put a bit too much glue. Use the tube end to spread such glue along the tire-rim mating surface.

Make sure that you glue around the spoke holes. Those little areas are hard to glue properly, and if you miss them, you're leaving yourself vulnerable to a tire rolling. Those missed spots are like perforations in your glue job. Get one spot loose as you dive into the last turn in a crit at 38 mph and you may find your tire popping right off the rim.

Using the tire lable to spread glue.

I felt it was important to upload this picture, but I forget why now. Look at it carefully.

Note the spiderweb kind of effect that bridges one of the spoke holes. That indicates the glue is getting a bit tacky. It is fine. Sometimes I've gotten enough glue on a rim that the whole spoke hole is hidden behind such spiderwebs. On this wheel, since I have to true it using those spoke holes, I've kept them open. On rims with exposed spoke nipples I don't care as much.

Once you have a layer of glue on the rim, spread it out. I try and use a discarded plastic bag or something similar. I've also used scraps of cardboard (bent a bit to follow the rim contour), even small brushes saved just for gluing tires. I like the baggie method best. Failing a baggie, a tire hang tag works fine. I fold it over my index finger, holding it in place with my thumb and middle finger, and spread the glue carefully.

When you're done with a layer on the tire and rim, and it looks and feels like it's sticky from edge to edge, wait for a bit until it gets tacky. Then you can do a second coat. This time you want to work a bit quicker - it's easier to set and adjust a tire when the glue is a bit wet.

I find it better to put a thin coat on the tire, spread it, then a slightly thicker than thin coat on the rim, and spread that. By the time you finish doing the rim, the tire's glue will have tacked up some, and it'll be ready to go.

You want some rim glue to be wet because it makes it easier to center the tire on the rim. Otherwise you'll be stuck with a wavey tire tread that wears weird and rides unpredictably. A squishy layer of glue on the rim is good.

Now you're ready to mate the tire to the rim. Remember to deflate the tire! It'll be hard to mount a flounder-like tire onto a normal rim.

Then, quickly, do the Pinch Hold and Toe Grip method and get that tire on, starting at the valve. Stretch and pull the tire evenly away from the valve, making sure the valve stays straight. The Pinch Hold comes in handy for the last few inches of tire, and the Toe Grip counters your Pinch Hold efforts. Your earlier practice will come in handy now.

With about 20-25 psi in the tire, roll it on the floor while pressing down.

This helps get the tire into contact with all that glue that you painstakingly applied next to the spoke holes. If you don't do this, and you inflate the tire a lot, the air pressure will lift the edges off the rim, and the glue won't have a chance to set. This results in just the center being glued, and that's not good.

Presto, you're done!

Or... not. You really ought to wait at least overnight to ride the tire, and 24-48 hours is better. Check your glue job - if it doesn't look like the last picture of in this post, it's not good enough. Do it again.

You want to see the glue clinging tenaciously like this.

If you don't glue your tire well, it'll roll off. And if your tire rolls off, you'll get hurt. So be extremely and correctly confident that your tire won't roll off.

4 comments:

Suitcase of Courage said...

Wow. I am SO going to stick with clinchers - unless I have a team mechanic doing the tubs for me. %^)

Great step-by-step on how to do it though.

Anonymous said...

Thanks Aki. Amazing tutorial!
Brad

Aki said...

Brad, I hope your gluing goes well.

Would you be the one that came to Bethel this year (and your brother one week that you weren't there?). If so I have some pics of you at SUNY Purchase at one of the last Tues Night Sprints ever.

Anonymous said...

Yep, that was me who raced Bethel for the first time this year. (My brother did it once and our friend Jean-Marie a couple times.)
I cannot remember the last time I rode SUNY; that must be over 15 years old. Can you send 'em via email to blapin@hotmail.com?