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Tubular gluing problem

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Old 10-13-15, 03:41 PM
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kenl666
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Tubular gluing problem

I consider myself an experience tubular gluer but I glued some tires for someone and they rolled (this is the first time that a tire I glued rolled). Just to be safe I had him bring the font over when he dropped the rear wheel off to be reglued, the front tire came off real easy so it probably would have rolled too (and THAT would have been a bad situation).

The rims are Mavic Helium, the tires are Clement PDX Tubeless 33, I used Vittoria Mastik.

It was obvious that the basetape only made contact up near the top of the rim bed (near where the hook would be if these were clincher rims), the glue in the bed of the rim was just about untouched. I had rolled a broomstick on the tire to push the basetape into the bed when I glued them so I was surprised (and disappointed) that it either didn't seat all the way down or didn't adhere for some reason.

The tires are old, the basetape looks a little dirty but today I made sure to go over it real good with solvent, I also shaved off some of the glue buildup.

Any suggestions? I'm thinking that I need a broomstick handle with a smaller diameter to get the basetape down in the bed.
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Old 10-13-15, 04:16 PM
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Originally Posted by kenl666 View Post
the front tire came off real easy so it probably would have rolled too (and THAT would have been a bad situation).
Speaking from experience (broken jaw, 13 chipped or cracked teeth, they had to scrape the dirt out of my chin bone before they sewed me up), you are very right. Tires old? Base tape dirty? Your choice, but I'd strip off the tape and replace, and buy new, snug tires. I may be gun shy, but weighing the cost of failure against the trivial cost of new tires is no comparison for me.
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Old 10-13-15, 04:18 PM
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the broomstick (edit: as mentioned ) may have had a diameter a little too big. it doesn't take much. it needs to be much narrower than the rim's inside width to accomodate the sidewall and tread of the tire to do much good.

and i've noticed that rims may not have a uniform radius in the bed either.

i just looked up that tire...

is this the one? http://content.competitivecyclist.co...CLM0005/BK.jpg

the ones i found have huge knobs on them. i'm assuming they are a cyclo-cross tire. i guess i'm not surprised that it would be difficult to bed those tires unless the seam tape fit the contour of the rim bed perfectly when inflated. could just be a bad match between shape of inflated tire and rim.

Last edited by hueyhoolihan; 10-13-15 at 04:33 PM.
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Old 10-13-15, 04:31 PM
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Sounds like the curve of the rim didn't match that of the tire. If so then the problem began with a poor tire/rim combo. But one's gluing methods can also contribute to rolling/inadequately secured sew ups. Please describe your process.

If both the rims and tires are new then there needs to be prep layers of glue laid down before the final bonding one.

New tires can have very porous/"raw" base tapes or base tapes with a coat of some sort of latex/sealant. The raw tapes are pretty much cloth and will take in the prep glue deeply and still not have a good surface for the bonding layer to bite on to. I will lay on tow (sometimes three) layers of glue on raw tape before getting a sufficiently prepped surface. Already coated (or used tires with an old glue layer) tapes usually only need one prep layer. But experience and prudence are vital here.

New rims need some pre glue prep too. Wipe off rim with a non residue leaving solvent. Scuff/sand the rim best possible to remove any shine and establish a surface with bite. A prep layer of glue is next. Some rims work best with a second prep layer, those with double spoke eyelets as example.

For both rims and tires the prep layers should completely dry, only slight tack to the touch.

Only now will I apply the bonding layer of glue the rim and quickly (did you stretch the tire for a day+) mount the tire, partially inflate and align it then fully inflate. A good glue job will have small mounts of glue beading up at the rim/tire edges.

I have used these methods for 40+ years and the only tires I have ever rolled (both my own) were after a flat and the spare was mounted with only old glue to hold things in place (or not) and later aggressive cornering. Since then I carried double sided rim tape for on the road flat mounting (Jantex). Andy.
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Old 10-13-15, 04:54 PM
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Originally Posted by Andrew R Stewart View Post
Sounds like the curve of the rim didn't match that of the tire. If so then the problem began with a poor tire/rim combo. But one's gluing methods can also contribute to rolling/inadequately secured sew ups. Please describe your process.
This wheelset was purchased used with the tires on, the guy said that just they'd been sitting in the garage for a few years. When I removed the tires for the first glue job I noticed that the basetape wasn't seated then, so it's not like this was a good gluing job that I screwed up.


I cleaned the wheels with solvent, let it dry a day, and then put a coat of glue on both the rim and basetape. Let that dry a day then put a second coat on the rim. Waited about 20 minutes and then put the tires on.
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Old 10-13-15, 05:00 PM
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Yep, those are the ones. It's a CX wheelset. Interesting thing is that he said he was going uphill when the tire came off.
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Old 10-13-15, 06:58 PM
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Cross tires are naturally much more prone to rolling with low pressures, lots of steep off camber, usually a lot of pressure washing and nasty conditions, etc. While I have had good luck with the more traditional glue methods it would be worth checking out "Belgium tape". Lots and lots of cross guys seem to swear buy it, especially when the rims are a bit on the narrow side. You can get it and see how to use it here. Cyclocross Tires - Gluing with CX Tape :: Belgianwerkx

The other thing to pay particular attention to but applies to all types of tubulars anyways. Make sure you are getting glue all the way to the edge of the rim as that is the most critical place for the tire to be attached firmly.


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Old 10-13-15, 07:32 PM
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"Let that dry a day then put a second coat on the rim. Waited about 20 minutes and then put the tires on." kenl666

I never have read of or been taught to mount the tires after the bonding layer has time to dry. I think this contributed to the problem. I mount most of the sew ups at work. We run a Fall CX series (Ellison Park is our UCI C1 and C2 events) and I see a number of getting ready for the series mountings with various wheels and tires. So far so good with the above method I use. Andy.
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Old 10-13-15, 08:20 PM
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Originally Posted by chriskmurray View Post
Cross tires are naturally much more prone to rolling with low pressures, lots of steep off camber, usually a lot of pressure washing and nasty conditions, etc. While I have had good luck with the more traditional glue methods it would be worth checking out "Belgium tape". Lots and lots of cross guys seem to swear buy it, especially when the rims are a bit on the narrow side. You can get it and see how to use it here. Cyclocross Tires - Gluing with CX Tape :: Belgianwerkx

The other thing to pay particular attention to but applies to all types of tubulars anyways. Make sure you are getting glue all the way to the edge of the rim as that is the most critical place for the tire to be attached firmly.


+1 The CX tires are too wide for the rim and not seating into the rim. The CX tape should solve this problem.
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Old 10-13-15, 10:15 PM
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Thanks everyone for the tips, appreciate it! I'll do it differently this time, not wait for the final layer to dry before putting the tire on.
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