Glueing tubulars [the tubular thread]

Everything about building wheels, glueing tubs, etc.
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astranoc
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by astranoc

Do CX tyres need anything different on the gluing process?

sungod
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by sungod

i don't know, but i been told, that you do it with a combination of glue and belgian tape (not tufo tape) http://www.cyclocrossworld.com/thorne-p ... bular-tape

there's a guide here from someone who does it in bulk...

http://www.embrocationmagazine.com/onli ... x-tubulars

ldamelio
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by ldamelio

The definitive way is in the following video - glue and tape - this is Belgian cross tape and NOT the Tufo-type tape sometimes used alone for road tubulars. There are some who say glue alone is sufficient. I have seen dozens of races lost from rolled tubulars at all levels of cross with glue alone. The lateral forces on the tire/rim interface are much higher than on the road, not to mention the effects of water, mud, sand, etc. on the glue job. Do it this way:

http://www.cyclocrossworld.com/How-To-G ... _b_43.html" onclick="window.open(this.href);return false;

Edit: sorry, near identical reply above. In any event, you have the definitive answer.

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mellowJohnny
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by mellowJohnny

dj97223 wrote:Geoff,

Are you saying start at the valve?????


No, he's saying valve facing down, so start your removal directly *opposite* the valve.

Geoff
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by Geoff

@dj97223, no. The valve-side down on the ground.

@astranoc, absolutely. Gluing of 'cross tires uses the same basic techniques, but there is one major difference.

In recent years, riders have turned to carbon wheels for the dual purpose of lighter weight and the ability of the carbon rim to sink deeply into mud or sand without the substrate 'closing' over the top of the rim, making it easier to ride. Due to the cost of making carbon rims, and due to the more limited market, there are not 'cross-specific rims. Accordingly, 'cross tires are glued to road rims that have been re-purposed for use in 'cross. The problem is that 'cross tires have much larger cross sections than road tires. The larger section does not 'fit' the rim bed of a road wheel as well as road-sized tires do. In order to improve the fit of the 'cross tire to the rim bed, a 'filler' is used.

The 'Belgian Tape' referred to by Sungod is used to fill the gap created between the basetape and the rim bed. It also serves to provide more structure to the glue for the sideloads that 'cross tires are subject to. To install it, I would recommend the same basic steps for the preparation of a road rim (i.e., several thin, even layers installed over a period of days) with the same glue (Vittoria Mastik 1, for me). Once the basic glue job is completed, the Belgian Tape is installed by very firmly pulling it into the glue so that the glue 'seeps' through the mesh of the tape. Once the Belgian Tape is installed, additional layers of Mastik 1 are applied over it, in the same fashion as the base layers were. Thereafter, prepare and install the 'cross tire in the same fashion as a road tire.

The last step for the installation of a 'cross tire is to apply Aquaseal/Aquasure. Sitting, I lay the wheel down on my lap. I run a bead (you will need a fairly thick bead for a 'cross or MTB wheel) all the way around. With a thick piece of poly sheet (or a heavier retail-type bag) over your finger, spread the bead out over the sidewall. The idea is to get an unbroken seal between the tread and the basetape/rim interface. You will want to make sure you get a pretty good bead down where the basetape is so that it will not wick water up under the tire. It just won't dry well there. If it gets really soaked, the water can soak through to the casing and rot the casing fibres. Once you have it done, leave it lying flat and go on to the next wheel. When it is dry, flip it over and do the other side the same way.

Incidentally, I install MTB tires the same way as 'cross tires.

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astranoc
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by astranoc

Thanks very much! Is the belgian tape known as something else as well that can be bought from a hardware store?

fdegrove
Tubbie Guru
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by fdegrove

Hi,

If it's textile tape then I suppose it's Jantex. This is covered in Tubasti rim cement (white). Not sure hoW well that integrates with the totally different Mastik One....

Ciao, ;)
Last edited by fdegrove on Fri May 24, 2013 2:39 pm, edited 1 time in total.
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Geoff
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by Geoff

That's what I thought, too! Being...well, cheap, I got some Jantex myself.

When you look at Jantex, it is clearly different from what we know as Belgian Tape in North America. The main difference is that it seems woven 'tighter'. Part of the 'secret' of the Belgian tape, in my mind, is that it helps give some 'structure' to the glue which helps it resist the unique shearing forces experienced in 'cross and not seen in road use. In order that the tape do this, the substrate glue needs to 'soak' though the tape. This may still happen with the Jantex, but for $30, I wasn't going to risk finding out.

From e perspective of sources, you can get it on-line from the 'usual suspects' for tires in North America (i.e., Roger at WCC and Stu at CCW). I am not sure if the product offered by Roger is the same as Stu's product, as I have not tried it yet. The stuff Stu sells will last a looooong time (based upon how many 'cross and MTB tires I glue, anyway...)

Frank, what do the real Belgian 'cross riders use? I'm sure Stu is getting the tape from somewhere in your neck of the woods...

fdegrove
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by fdegrove

Hi,

@Geoff: As far as I know they (most of them anyhow) use Jantex tape and Mastik One.
This has been discussed in this thread (never mind some of my more vitriolic replies... :mrgreen: )

http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=101567

Ciao, ;)
Last edited by fdegrove on Sat May 25, 2013 11:28 pm, edited 1 time in total.
Being a snob is an expensive hobby.

RWH
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Location: Turku, Finland

by RWH

Image Image

Wanted to change from clinchers to tubulars again now the weather here in Finland starts to improve significantly and road conditions are OK now.
The tubulars are Veloflex Carbons, which were glued last year June and ridden till the end of the season (about 1000 km). Afterwards stored in a cellar in the dark.
When I put them away the only damage were some nicks from little stones which had been lodged in and removed from the tread.

However when I wanted to mount them on the bike again this week, I noticed the tread on the rear wheel was damaged/cracked over a length of about 50 cm roughly starting from the valve.
Is this something to worry about? Should I replace the tire? Or is this just surface damage with the integrity of the tubular not compromised as the casing will take all the stresses?


NB: And yes, I glued them slightly off center :oops: , as wear seem to be towards NDS (1st glue job, will do better next time)
Never give up, never say die.

fdegrove
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by fdegrove

Hi,

Afterwards stored in a cellar in the dark.
When I put them away the only damage were some nicks from little stones which had been lodged in and removed from the tread.


Strange, very strange.
Those tyres look as if they've been exposed to direct sunlight a lot and aged accordingly. My Veloflex tyres do not tend to embed small stones, Vittorias do however.

Either way, yes, those tyres are mounted off centre and yes, they look pretty close to end of life to me.
No idea what the cause of those cracks are but I suspect those are caused by glass shards. Something you'd notice as the tyre wears down and is hidden from view when the profile is more pronounced?

Ciao, ;)
Being a snob is an expensive hobby.

Geoff
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by Geoff

I have seen that a lot on really old tires that have oxidized over time. I have never seen it happen over the course of a season, though. I have ridden tires with cracked treads before without any ill effects. I think you are fine to ride them, assuming the glue is good.

RWH
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Location: Turku, Finland

by RWH

OK, thanks guys. I will just ride them and see how long they last.

Funny, you mention them being exposed to direct sunlight a lot, when the bike is not ridden it is always in the dark of the cellar.
Perhaps Finnish sunshine and Veloflex don't match :-).
Some other data related the tire, as I recall, the manufacturing date stamp on these tires was August 2011. They were purchased from Bike-Palast in January 2012 and mounted mid-June 2012.
Also problem occurs on the rear only, not the front.

And regarding the off-center mounting, as this is close to the valve, is it possible the tread was moulded a bit off center, as the valve is the only 'rigid' mounting place on the wheel. Most likely best centered place on the wheel by default?
Never give up, never say die.

sungod
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by sungod

finland, maybe it froze :-)

fdegrove
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by fdegrove

Hi,

Finnish sunshine frying Veloflex tyres, he... :lol:

And regarding the off-center mounting, as this is close to the valve, is it possible the tread was moulded a bit off center, as the valve is the only 'rigid' mounting place on the wheel. Most likely best centered place on the wheel by default?


The thread is actually glued on. I've to find a Veloflex tub that was not correctly centered on the casing but I suppose it can happen. Shouldn't have left the factory that way though.

Ciao, ;)
Being a snob is an expensive hobby.

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