JohnES

Hello, This is my first attempt at mounting tubulars at home. Started with new rims (aluminum) and new Vittoria Corsas.

I read several places that the excess latex needs to be removed from the base tape in order for the glue to adhere properly. I used a file (as suggested many places) and the excess latex came off in gummy blobs. It took about 20-30 minutes of work to clean each tire. The base tape looked suitably cotton colored when I was done, but was a little but fuzzy form being abraded.

After I applied the first coat of glue (Vittoria Mastik One) the surface of the base tape was lumpy from the glue coating the stay fibers. Is this normal or have I just ruined a nice set of tires?

Thanks in advance for your advice!

Regards,
John

rpenmanparker 

I have never done that. Hard to believe the new tries aren't sold ready to mount.

Not everyone agrees, but I am a strong proponent of Tufo gluing tape instead of glue. Totally mess free. There are other brands also that have their own fans.

DiabloScott

I've never done that either. I doubt you ruined anything though. Install, cure, inspect, ride.

joejack951

@Psimet; on this board is a big proponent of removing that coating on the base tape. If striving for the absolute strongest bond, sure, it makes sense I guess. I left it on and only cleaned it with acetone before applying Mastik One. I had to remove one tire to retrieve a spoke nipple that fell inside the rim and in doing so I gave myself a monster blister on my thumb. I also got to see what the tubular glue stuck well to and what it didn't. As it turns out, it stuck equally well to every surface with some glue staying with the tire and some with the carbon rim and some of the glue stuck to the rim also ripping off some of that base tape coating.

Per my informal test I see no benefit whatsoever to removing the coating. But I can't see it hurting either. What you've described of the appearance of your basetape doesn't sound detrimental in the least.

JohnES

Super. Thanks for all your replies. It was probably an unnecessary extra step, but I wanted to try to do it correctly my first go-round. In hindsight I would not have tried to scape the latex off.

I will mount the tires then, and after a good cure, check the adhesion. I was just concerned that the slight bumpiness might inhibit full surface contact between the rim and base-tape, but the glue itself is soft enough to deform under pressure so... maybe the bumps will flatten out in the end? Time will tell.

One more question. I have read that one of those 30 ml tubes of Mastik One should glue two sets of tires/rims. Is this true? I will have used two full tubes (one tube per tire) before I'm done. Have I used too much? I tried to keep my layers thin (2 on the rim 2 on the base-tape) and used way less than most of the YouTube videos seemed to suggest.

Anyway, thanks again for all your help!

JohnES

Sorry for the nervous-newbie barrage!

I got the tires seated and straight and let them cure 24 hours. Today I deflated the rear and checked for adhesion. There was glue all the way around between the base-tape and rim-edge (except for a stubborn part at the valve where it doesn't want to seat correctly--despite drilling out and chamfering the valve hole).

BUT! when I gently pushed up on the glue joint the tire broke away from the rim quite easily with very little pressure.
Is this normal?
Is this because the Mastik One was not yet fully cured? (It had been almost exactly 24 hours)
Also, I am a little worried that I may have been overly aggressive when straightening the tire out on the rim. Did I take too long and compromise the glue joint?

rpenmanparker 

That is not normal or proper. It did not come from straightening the tires. Perhaps your glue layers are too thick and not set yet. Wouldn't that be supported by the observation that you were using more glue than believed necessary?

woodcraft

Did you clean & lightly sand the rims?

Psimet2001 

1. We remove all of the latex from Vittoria road tubulars before gluing. If you don't do so the tire/glue bond WILL fail at the coating. I have witnessed it happening 4 or 5 times. Twice on tires we glued. The latex to the cotton base tape bond isn't as strong as the Mastic bond so what ends up happening is that the latex separates from the cotton under stress. The factory coating is where the bond fails.

We buff the tape removing most of the latex and "fluffing" the cotton on the pbase tape at the same time. Little hairs of cotton will stick up. Glue will soak in and become a deep golden brown on 2 coats.

2. OP - NO - the tire should not come up under pressure from your thumb. An overly weak bond when using Mastic 1 can be caused by a couple of factors:
A. The glue itself. There was a batch of glue that hit stateside about 3 years back that was quite simply sub-par and led to a lot of failures. It had a milky caramel look to it instead of the clear amber look that it normally has. Vittoria gave it the OK but I witnessed it turn into easy tire separations. Also - the mastic has a general shelf life. If you bought it out of a dusty bin in a bike shop that looked at you funny when you asked for mastic then don't use it. Get it from somewhere that glues a ton so the supply iis always fairly "fresh". It's not the shelf sitting that does it in as much as the temperature fluctuations - especially if it is stored somewhere where the sun shines on it once a day.

B. coatings applied too thick. In this scenario the coating is simply too thick to allow the depth of the glue to cure. The only way to fix is to strip the mastic and restart. Use thinner coats and allow proper curing time of 6-24 hrs. per coat.

C. Not enough cure time. If the coats don't sure they just simply have little to no holding power.


From what you describe you need to remove the tire and do a diagnosis. Odds are there is a ton of glue on the tire itself and most of what you put on the rim is gone. Indicative of coatings that were too thick and full curing didn't happen between coats. The most important step if prepping the rim in the same manner as you prepped the tire. Clean it with rubbing alcohol after sanding it lightly to remove anything that has made its way onto the rim before gluing.

VM&P Naptha is a solvent you can use that is readily available in any hardware store, Walmart, big box, etc. It is less volatile than Acetone so you have more time to work with it and is safe to use on all tire and rims.

cycledogg

Odd, very odd. I have glued several Vittoria brand road tires, Corsa Evo CG CX and Elite etc. and I have never "prepped" the base before applying glue. I have always used Vittoria Mastik with no bonding issues.

JohnES

Thanks for all your replies!! My glue (from amazon) looked more amber/transparent than milky/carmel, but that is an interesting point.

The rims were lightly sanded and cleaned with acetone just before gluing.

I let each layer of glue cure 24 hours between coats.

The layers looked thin to me-- again, thinner than what I saw on some of the instructional videos. But, seeing as this is my first attempt at gluing, I'm sure that the likelihood of messing up is quite high. Can someone confirm that one of those little 30ml tubes of Mastik One is really enough for two sets of tires/rims?

When the tire was pulled up there was glue clinging both the rim and tire. It seemed to be the bond between the two (or the final coat on the rim) that gave up in gummy strands.

I am away from home for a couple of days. When I get back, I will check the bond again, and if things haven't improved, maybe I will take them to a local pro shop. (And prepare for the lecture that there is no reason to use tublars these days...)

Thanks again for all your help!

Psimet2001 

Not enough glue. It's hard to come up with a guideline as I just use the amount of glue needed to do the job. It varies by tire size and type as well as rim bed depth, etc.

In general though you can expect to use at least 1 tube per wheel. I wouldn't start a gluing project without 4 or 5 tubes on hand and would expect to use up 2.5-3 of them.

JohnES

Hi Everyone,

Just got back and checked the tires after another three more days of curing. They still pull off easily with gummy strings left behind.

Psimet2001: So I checked my tubes of glue. In the end I opened 3 tubes-- I didn't want to run out on the final coat (the rim coat just before mounting), so I opened a new tube. That tube has different graphic design (something I didn't notice until now) and -low and behold- it is less golden/transparent more caramel/milky. I guess I wasn't paying attention to the glue on the last coat.

Now, do I need to remove that glue to start over? Or do I just get some new glue and add on top? Can it safely be removed from the base-tape?

Thanks!

Best,
John

big chainring 

I think somewhere in the transition from the post war era and the modern computer age the simple skill of glueing has been lost. As a kid Elmers white glue was a staple of early childhood learning. It had a learning curve. Too much, too little, dry time, etc.

The idea is simple. Glue a tire to a rim. Let it dry. Go ride. The tire already is tight on the rim. You just need some glue to keep it in place. I use 3M Fastak from the auto parts store. About 5 minutes a tire. I mount the tire on the rim. Pull a small portion of tire away from the rim, apply glue. Work around the wheel in that manner. With Fastak an hour dry time and you're ready to go.

In 40 plus years, criterium racing; track racing, 10's of thousands of miles, never had a problem.

rpenmanparker 

I make no claims to have done it the right way back when I was using glue. I just put some on the rim. Let it dry for a few minutes, then mounted the tire. Next morning I rode that wheel and never had a problem. No multiple layers, none on the base tape, etc. But like I say, that was just me and back then. These days the protocol has grown into a significant project. So be it. I have given up on the glue in the tubes and switched to gluing tape. I know some folks find fault with it, but I think it is fine for my needs.

Sangetsu

I ran tubulars for years, and never did anything to the tires other than glue them on. It sounds like whatever you have used to remove the excess latex caused it to become uncured, and become a sticky mess.

It is a bad idea to enter the world of tubulars by buying expensive tires. You should be running Rallies (Vittoria's cheapest tubular) until you have gotten some practice mounting new tires.

The only prep I would do would be acetone on a rag to remove any glue from the rim. Then I would stretch the tire by stepping in it, and pulling up with my hands, this makes it a bit easier to get onto the rim. once the tube is on, I would inflate the tire a little bit, then twist the tire as needed until the base tape was showing evenly around both sides the circumference of the wheel. If I installed the tire in the morning, it was safe enough to ride in the afternoon, though I usually let them cure overnight.

JohnES

Update:
I took my wheels to a local pro shop that assured me they glue tubulars on a regular basis. The mechanic, a reassuringly older gentleman, carefully pulled off the front tire, inspected the glue, and told me I had done a good job, and to go home and do it agian. He said the glue bond strength was good, and they were holding just fine.

So I reglued the tire, and have ridden a few times. Nice feeling tires.

Thanks again for everyone's input!