Glueing tubulars [the tubular thread]

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

We used to ride Barum tubulars! Compared to those, Vittoria Rally are race-day specials...

Jaspero
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by Jaspero

Geoff wrote:
Wed Jul 04, 2018 12:31 am
It sounds pretty good to me. Once you let it cure, take some air out of it and try to push it off with your thumbs. I'm betting you'll find it is really solidly attached to the rim.
It was indeed. Did two trainingraces on them to test. Went good so ready for A race this sunday.
22 is a bit narrow coming from 25mm clinchers. Wasn’t sure if the wheels can take 25mm tires?
12F3D6A0-D066-4129-A4BA-428D8043E9C3.jpeg
Ccu

by Weenie


sungod
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by sungod

most rims will be ok fitting 25mm

bear in mind having a tyre bulge too much wider than the rim will start increase drag and may affect handling in strong crosswind

Jaspero
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by Jaspero

Thanks sungod.
The vittorias cxiii are sitting flush now with the rim. They are actually 23mm, i had the spare 22conti tub in mind probably.

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PinaRene
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by PinaRene

@ Jaspero - I had the same Mavic wheels with 24mm Schwalbe One tubulars mounted on them, but 25mm will also be fine on them.

Geoff
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by Geoff

Looks really good to me, too.

petepeterson
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by petepeterson

Sharing a recent experience in case this helps someone out there on the interwebs googling tubular slow leak.

After having great experience (feel, flat resistance, durability etc) with Conti Competitions for several years I decided to try the new Vittoria Corsa G+ tubulars again on a new set of Bora 35's. I found the old Corsa's were not great in wet and prone to flatting often on my roads so had gone away from them in recent yrs.

After my first short ride on the wheels/tires I was heartbroken to discover a slow leak on the rear. I couldn't find any cuts/debris that would explain so looked elsewhere thinking maybe the tube was still fine. And yes - I know the tubes are latex and leak air.

Next check were the schwalbe vavlue extenders. I re-tightened them and refilled the tires. Next morning flat again.

At this point I decided my last option before sealant was to try removing the extenders to see if I could remove that variable while being able to air up the tires. I found I was able to just get the pump on and air up the tires with no extenders on the Bora 35's. Next morning I was delighted to discover the leak was gone!

This is the first time in years of running tubulars by Veloflex, Vittoria, Conti, Tufo (i know, sorry), etc with valve extensions that I've had a leaky valve extender issue. So keep this story in mind if you're having similar slow leak issues.

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Calnago
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by Calnago

I’ve learned to wrap some Teflon plumbers tape in the threads of extenders and tighten them up BEFORE mounting. I use a Lezyne Road Drive pump on the road and it threads onto the valve. If the extender isn’t attached tightly it’s quite easy for it to come loose and leak. It’s been so long since I’ve had a flat on the road I’m starting to forget this stuff.
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addictR1
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by addictR1

Yup I use Teflon tape before installing the continental valve extenders onto veloflex.

Pump 120psi the night before and by morning probably have 85-90psi left. I just repump before heading out.


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KCookie
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by KCookie

addictR1 wrote:
Wed Jul 25, 2018 8:06 am
Yup I use Teflon tape before installing the continental valve extenders onto veloflex.

Pump 120psi the night before and by morning probably have 85-90psi left. I just repump before heading out.


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Depending on your weight, why repump. Thats the pressure I ride all the time on Veloflex.

sungod
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by sungod

petepeterson wrote:
Tue Jul 24, 2018 9:57 pm
...This is the first time in years of running tubulars by Veloflex, Vittoria, Conti, Tufo (i know, sorry), etc with valve extensions that I've had a leaky valve extender issue. So keep this story in mind if you're having similar slow leak issues.
i found the same with g+ tubs, extenders that work fine with veloflex and conti will leak (unless wrapped with ptfe tape)

i got some vittoria extenders by chance, the rubber seal was chunkier, they didn't leak, no tape needed

seems like the vittoria valve stems have a slightly larger inside diameter than others

Geoff
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by Geoff

The other thing to consider is which extender. My personal preference is for the old, plated brass Vittoria ones, versus the newer, alloy ones. Yes, the old ones are heavier, but I think that the fine threads hold-up better than the alloy ones do. Just look for the ones with the chrome finish, instead of the black finish.

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eurperg
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by eurperg

I’m gluing 30mm Schwalbe G-one tubulars on latest generation Bora rims. They will be used for mixed-surface riding, half tarmac and half gravel. I will be riding with 3-4 bar pressure.

Would you glue them like road tubulars (3 layers like Campagnolo and Schwalbe instructions say), or like cross tubulars (5-6 layers like every cross tub gluing tutorial on the internet says)?

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Calnago
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by Calnago

Since they’re Schwalbe tires, I’d start by following Schwalbes instructions. I’ve never glued tires that big to Boras so I’ll be most interested to see what the center of the rim and the center of the tape looks like after you eventually remove them. Should all be fine, but I’m curious if, due to the larger radius of the tire, it tends to want to pull away from the center of the rim bed over time. That would be the main reason for perhaps using more layers, but if I did that I’d try to taper the thickness of the layers so that it effectively decreases the radius of the rim bed to better match the larger tire. Maybe just do as Schwalbe recommends with the addition of one bead of glue smack in the center of the rim bed just before mounting. Just a thought. Would like to know how you think the glue job worked when you eventually remove them.
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Geoff
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by Geoff

Wow. Those things are huge!

I occasionally run 31s in 'cross. I would never think of gluing those tires without 'Belgian' tape. I believe that there is no way that tires will glue-up propertly for 'cross without that technique. Having said that, you are running those on the road (or gravel). The reason that the 'Belgian' technique is so important in 'cross is that you are running pressures down to 20 psi (or lower), which causes different forces to act against your glue job and inreases the risk of a roll-off. As you aren't running 'cross pressures, I think you will be ok with a 'conventional' gluing technique.

On the Schwalbe instructions, I still think that you will have better luck with placing more, thin layers down on the rim and rim tape. Ifg you do the 3 on the rim bed as you propose, and then a couple on the basetape, I think that will work well. If you do that right, the rim and basetape should bond really well at the road-biased pressures that you will be running. Your 30s are big, but they really aren't that much bigger than my Dugast Seta 27s. I have been gluing those using my 'conventiona' method for many, many seasons. They stick-down perfectly on road rims. In the Pro Tour, they have also been conventionally gluing large-volume Paris-Roubaix-sized tires for decades with no issues. Incidentally, I would also still recommend Mastik 1 over the Schwalbe or Conti glue.

Let us know how that goes and how they run!

by Weenie


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