Glueing tubulars [the tubular thread]

Everything about building wheels, glueing tubs, etc.
Geoff
Posts: 5093
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

Sounds like a good job on the gluing. With respect to the spares, there are probably any number of options. As I say, I have the dual issue of preferring better quality tires and being too cheap to buy a special tire to use as a spare! Accordingly, I just use an old tubular that has not punctured yet. The added benefit is that it the tire is proven to fit the rim perfectly.

I have never tried to lay the basetape together for it's entirety like that before. My concern is that the glue will clump and not provide a nice, even layer. Let us know how that goes.

by Weenie


thprice
Posts: 238
Joined: Sun Jul 17, 2011 6:34 am

by thprice

RC856 wrote:...Anything else that folds up small?

http://www.tufo.com/elite-135g/, 22mm width, rolls up tightly and easily fits in jersey pocket.
It is a track tubbie, no puncture protection layer, but good enough to get you home in an emergency.

ibrahim
Posts: 1
Joined: Wed Jul 23, 2014 1:25 pm

by ibrahim

Guys . May I know the reason why you stretch the tires ?
Is it really big difference in weights without inner tubes ?
I never used tubeless tires. Would someone explain?

sungod
Posts: 1462
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

some, but not all, tubular tyres may benefit from stretching before fitting, it simply makes it easier to fit them onto a glued rim

personally i've never needed to stretch them, i find veloflex go on fine with stretching, but it seems to vary a lot with make/model of tyre

tubular tyres have an inner tube or equivalent as part of the tyre, the weight saving is mostly in the rim rather than the tyre itself - a rim for clincher tyres needs to be strong enough at the edges to hold the tyre pressure without deforming and allowing the tyre to be blown off of the rim with potentially catastrophic results, a rim for tubular tyres does not need to handle this pressure at the edges so it needs less material

tubeless is not the same as tubular - tubeless is a type of clincher tyre that together with a compatible rim can hold the pressure without needing an inner tube, these rims are also heavier than an equivalent tubular rim

Geoff
Posts: 5093
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

+1. To add to what @sungod has correctly mentioned, for new-to-tubular guys, I would always recommend stretching the tires, as you will need every advantage you can get until you get used to the process (and that's all it is - a process you have to learn).

The reason you need to stretch tires is that they are purposely built smaller than the rims to ensure a good fit. Because they are often made of natural fibers, they tend to stretch naturally. If they were manufactured exactly to fit, they would become 'loose' over time. To fit them on more easily, you need to stretch them out a bit. Some are tighter than others. For a Dugast seta 27 Paris-Roubaix, for example, there would be no possibility of mounting (for me, anyway) without stretching.

The lighter weight of tubulars is really just a side benefit resulting from the rim being easier to manufacture with less structure (no bead lock required). The real benefit (to me) is their greater resistance to flats (basically eliminating pinch-flats) and the ability to run them with lower pressure without that risk (reducing rolling resistance, providing better comfort and better cornering and control).

On tubeless, that is relatively new technology for road. Basically, they are similar to auto and moto tires with the bead providing both the fastening to the rim and the pneumatic seal in one, with the rim being designed seamlessly and air-tight. I have been running a long-term 'test' on them as a system and will post a bit of a review in the off-season. So far, so good...
Last edited by Geoff on Fri Jul 25, 2014 10:12 pm, edited 1 time in total.

HillRPete
Posts: 2292
Joined: Tue Apr 12, 2011 8:08 am
Location: Pedal Square

by HillRPete

I never stretch my tubs. But I also don't pre-glue my spares, so I want a tight fit, with the little glue that's left on the rim. Not sure how good the glue would be after like a year anyway (seems to be my tub flat interval). Got to admit I never flatted in cold weather though, in warm conditions the little glue on the rim is sticky enough to limp home.

Contis sometimes need a bit of coercion, but now I moved to Tufo spares, and they seem to have just the right size for a tight fit that is still possible to mount roadside.

Thuekr
Posts: 30
Joined: Wed May 28, 2014 9:59 pm

by Thuekr

Jantex doing the job for me - no pre-stretching of Vittoria Rally 23c. [Use: road riding, not racing].

thechemist
Posts: 24
Joined: Mon Jan 07, 2013 2:56 pm

by thechemist

So maybe I glossed over this but for the gluing process is everyone using a truing stand? Surely there are some nice home made rigs or something simple that I can strap the wheel to and spin it as I glue?

THanks

shimmeD
Posts: 366
Joined: Thu Jun 28, 2012 10:52 pm
Location: eNZed

by shimmeD

If you have a truing stand, use it. Just makes it a bit easier to spin the wheel :wink:
Less is more.

RC856
Posts: 57
Joined: Wed Apr 11, 2012 12:37 pm

by RC856

I used my turbo trainer to hold the wheels by the skewers and it worked fine as well.

dha
Posts: 163
Joined: Tue Jun 12, 2012 4:40 pm

by dha

Cheap bike stand used here. Leaves your hands free to not get stuck to things!

Geoff
Posts: 5093
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

I have never done that before, but I am sure it would be easy. I still use an old piece of wood...

HillRPete
Posts: 2292
Joined: Tue Apr 12, 2011 8:08 am
Location: Pedal Square

by HillRPete

Moving this here so the "Latex Tubes vs Ultra Light Butyl Tubes?" is not derailed any further ...
fdegrove wrote:
Or what about ditching the basetape altogether, to eliminate any hysteresis losses it might cause?


The base tape is there for good reason, it protects the stitches from being torn.

Keep in mind also that whatever the crr test results they're just that, i.e plain lab tests.
In the real world you'll quite likely be more efficient overall on properly glued tubulars.
Vittoria's Mastik One is still the best rim cement for road use. Still, if you want to better your crr and don't mind cutting a tub when it's punctured to remove it from the rim then Terokal's 244 is your friend.

So what if one soaked the basetape with track glue, wait for it to cure, and then did a regular glue job on the tub to fix it to the rim (minus one layer for the basetape maybe). Could that limit the hysteresis losses maybe?

Or, as said, maybe Conti glue helps that already, as it hardens quite a bit over time.

(Just tossing around ideas.)

fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

It is not a good idea to use different cements on the same setup.

Also, it is not because a cement sets faster that is therefore better. Proper gluing technique is far more important.

Ciao, ;)

Edit: The cement I referred to earlier on is actually Terokal 2444, my bad. It's what I use with tubs such as Veloflex Record and Servizio Corse. It's measurably faster than any other cement but you know the drawbacks.
Being a snob is an expensive hobby.

timjsharpe
Posts: 12
Joined: Tue Jul 29, 2014 10:02 am
Location: Manchester, UK

by timjsharpe

+1 for this being an awesome thread. I've read all 2999 posts. Thanks to the 'Belgian Brothers' and everyone else who's contributed. My next glue job will be awesome.

FWIW I mounted my Continental Competition 25mm tyres using the Conti Carbon glue following the manufacturers instructions to the letter. I did this before reading this thread which goes to show that it can't be that hard...I'm dreadful at fiddling and fettling.

They went on fine but they are super tight. Had a right sweat on by the time I'd finished and needed a bit of extra glue on the base tape as some came off on my hands when finally fitting. But no reason to panic - they seem to be solid.

The Comps are a good starter tyres I think, particularly if you're used to, say, GP4000s.

If you're a newbie like me you might be expecting top end clincher levels of roundness. I'm not sure that's realistic. There'll be some irregularities there.

Also my first ride wasn't mind blowing. A bit buzzy through the hands.

But having done a couple of hundred k on them and having played with the pressures a little, they are coming into their own. They do iron out the road. The road buzz is gone. I'm not sure if you have to 'run them in' or something but it feels like that's what's happened.

So don't panic.

And thanks everyone.

by Weenie


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