Tubular via Clincher questions...

[Justinslow]

High as in much higher than in MTB tyres. 60 PSI is high in that scenario and latex just squirts out most of the time on tubs.
We are talking tubular tyres here, not tubeless. Tubeless road tyres are several times thicker than tubs and their tube together. That helps in giving the sealant some mechanical adhesion.
Stan's sealant is latex in an ammonia suspension with some tiny rubber granules. It is particularly susceptible to CO2 inflation.

Is there a "best" product then that you can squirt in and forget?

 

[Tim Hall]

High as in much higher than in MTB tyres. 60 PSI is high in that scenario and latex just squirts out most of the time on tubs.
We are talking tubular tyres here, not tubeless. Tubeless road tyres are several times thicker than tubs and their tube together. That helps in giving the sealant some mechanical adhesion.
Stan's sealant is latex in an ammonia suspension with some tiny rubber granules. It is particularly susceptible to CO2 inflation.

Ah. I wasn't aware of the greater thickness of the tubeless and how it affects things. Thanks.

 

[Yellow Saddle]

Is there a "best" product then that you can squirt in and forget?

I don't know. But I can give you some pointers and my reasons for saying so. You can then make up your own mind or better still, launch some experiments of your own. I just don't have enough personal experience with tubulars. I adopted clinchers in the 1980s and never looked back. Having said that, I had plenty of customers who believed all the lore around tubulars and that I had to deal with.

Sealants come in two basic varieties: latex based and other. The latter is typically a glycol concoction that doesn't congeal but is a great carrier for all sorts of hole-plugging substances ranging from paper mache to rubber granules, maize flour and polyethylene beads. A thick liquid (glycol) keeps the bits in suspension and when a tyre is punctured, air forces the gel through the hole and some of the particles will block the hole. The substance never really dries out and it is just a mechanical blockage in the hole. Often just riding for a long time with the "repaired" tyre or washing the blockage out from the outside will renew the leak and it typically seals again. You can also see a continuous seepage and wet spot around the hole. The advantage of this type of sealant is longevity. You can keep it in the tyre for the tyre's lifetime. It doesn't dry out or deteriorate and isn't affected by CO2 inflation.

Latex congeals into a soft rubbery substance and jams the hole like a blob of glue would. The liquid solution congeals very quickly when it is forced through a tiny hole at speed. Most latex sealants will also contain a bit of rubber granules to help with sealing bigger holes such as one typically get when a twig punctures a MTB tyre. However, latex sealants dry out very quickly and form hard lumps in the tyre. On big tyres such as 2.5 inch MTB tyres where at least 200ml of sealant is required, this lump is the size of a golf ball and puts the wheel out of balance. On a good road you can feel the unbalanced wheel as a fore-aft oscillation on the bike. Note the feeling is not like that of a car with an unbalanced wheel but rather like a quickly-oscillating power surge. Latex sealants are an emulsion of ammonia water and pure latex. The ammonia preserves the raw tree sap that will otherwise just rot like fruit juice and, it dilutes it and keeps in nicely suspended throughout the solution. However, bring that in contact with CO2 and the pH changes and latex precipitates out - we say it crashes out of the suspension. This can be seen by a ball that suggests it suddenly clumps together and no longer wants to be part of the overall solution. Some people think it is the freeze brought on by the cold CO2 that causes it but temperature plays no role there, it is the chemistry of the solution.

Back to your question of should one put it in beforehand and what is the best? Yes, you should put it in beforehand if you want to benefit from on-the-go puncture protection. Which one is best I don't know. I do know that latex doesn't congeal when a 120PSI thin-wall tubby punctures. It shoots right out and makes an awful mess of you and the bike. However, it does congeal subsequently with lower pressure. That means you have to re-inflate at worse or if you are lucky, it may seal once most of the air is out of the tub. The glycol-based sealant requires a bit of "meat" in the puncture to work and tubulars don't provide this. They are just too thin.

I suspect you may have some success with latex and occasional success with glycol (depending on the particular filler in there) but I can't tell you which will work best. I don't even know the UK brands available to you.

 

[Justinslow]

I don't know. But I can give you some pointers and my reasons for saying so. You can then make up your own mind or better still, launch some experiments of your own. I just don't have enough personal experience with tubulars. I adopted clinchers in the 1980s and never looked back. Having said that, I had plenty of customers who believed all the lore around tubulars and that I had to deal with.

Sealants come in two basic varieties: latex based and other. The latter is typically a glycol concoction that doesn't congeal but is a great carrier for all sorts of hole-plugging substances ranging from paper mache to rubber granules, maize flour and polyethylene beads. A thick liquid (glycol) keeps the bits in suspension and when a tyre is punctured, air forces the gel through the hole and some of the particles will block the hole. The substance never really dries out and it is just a mechanical blockage in the hole. Often just riding for a long time with the "repaired" tyre or washing the blockage out from the outside will renew the leak and it typically seals again. You can also see a continuous seepage and wet spot around the hole. The advantage of this type of sealant is longevity. You can keep it in the tyre for the tyre's lifetime. It doesn't dry out or deteriorate and isn't affected by CO2 inflation.

Latex congeals into a soft rubbery substance and jams the hole like a blob of glue would. The liquid solution congeals very quickly when it is forced through a tiny hole at speed. Most latex sealants will also contain a bit of rubber granules to help with sealing bigger holes such as one typically get when a twig punctures a MTB tyre. However, latex sealants dry out very quickly and form hard lumps in the tyre. On big tyres such as 2.5 inch MTB tyres where at least 200ml of sealant is required, this lump is the size of a golf ball and puts the wheel out of balance. On a good road you can feel the unbalanced wheel as a fore-aft oscillation on the bike. Note the feeling is not like that of a car with an unbalanced wheel but rather like a quickly-oscillating power surge. Latex sealants are an emulsion of ammonia water and pure latex. The ammonia preserves the raw tree sap that will otherwise just rot like fruit juice and, it dilutes it and keeps in nicely suspended throughout the solution. However, bring that in contact with CO2 and the pH changes and latex precipitates out - we say it crashes out of the suspension. This can be seen by a ball that suggests it suddenly clumps together and no longer wants to be part of the overall solution. Some people think it is the freeze brought on by the cold CO2 that causes it but temperature plays no role there, it is the chemistry of the solution.

Back to your question of should one put it in beforehand and what is the best? Yes, you should put it in beforehand if you want to benefit from on-the-go puncture protection. Which one is best I don't know. I do know that latex doesn't congeal when a 120PSI thin-wall tubby punctures. It shoots right out and makes an awful mess of you and the bike. However, it does congeal subsequently with lower pressure. That means you have to re-inflate at worse or if you are lucky, it may seal once most of the air is out of the tub. The glycol-based sealant requires a bit of "meat" in the puncture to work and tubulars don't provide this. They are just too thin.

I suspect you may have some success with latex and occasional success with glycol (depending on the particular filler in there) but I can't tell you which will work best. I don't even know the UK brands available to you.

Ok thanks some great info there. The thought of getting stuck out the back of the 22 mile TT I'm doing in a couple of weeks with a puncture in the cold, wearing very little is starting to worry me!

 

[Cuchilo]

Read the reviews on wiggle from the link i supplied . If you pop pit stop in and spin the wheel it will do its stuff . Add air after . It doesn't seem to work for everyone but at least the reviews are from people that have tried it
I raced and trained with it in my tubs all last season , i'd like to think that's why i had a puncture free year . Maybe it was luck , who knows .
Other than that , take a spare tub with you .

 

[Justinslow]

Read the reviews on wiggle from the link i supplied . If you pop pit stop in and spin the wheel it will do its stuff . Add air after . It doesn't seem to work for everyone but at least the reviews are from people that have tried it
I raced and trained with it in my tubs all last season , i'd like to think that's why i had a puncture free year . Maybe it was luck , who knows .
Other than that , take a spare tub with you .

Cheers, yeah did read a lot of the reviews, then other products were mentioned so as usual got lost in a world of different sealants!
I like the idea of putting some in before the dreaded puncture, particularly as my tubs are "used", the rear has several small cuts in the tread.

 

[Yellow Saddle]

Read the reviews on wiggle from the link i supplied . If you pop pit stop in and spin the wheel it will do its stuff . Add air after . It doesn't seem to work for everyone but at least the reviews are from people that have tried it
I raced and trained with it in my tubs all last season , i'd like to think that's why i had a puncture free year . Maybe it was luck , who knows .
Other than that , take a spare tub with you .

I can say with certainty that you had a puncture-free year. When you do get a puncture and there is sealant in the tyre, you will know about it. It makes the same hiss but it also spits sealant around a bit before it seals. Even if you were in dense traffic and could not hear, you would find sealant inside the fork and underneath the downtube when you wash your car. It is never an uneventful event.

 

[adscrim]

Cheers, yeah did read a lot of the reviews, then other products were mentioned so as usual got lost in a world of different sealants!
I like the idea of putting some in before the dreaded puncture, particularly as my tubs are "used", the rear has several small cuts in the tread.

If you're going to run with sealant from the offset make sure any sealant you're carrying is of the same brand. Introduction of latex solution form a different manufacturer, and as such possibly a different pH, can kick start polymerisation. Also, some manufacturers don't agree that it isn't the cold shock that starts the latex coming out of solution so if using CO2, Effetto Mariposa (who make Espresso latex repair cartridges - and make it specifically at a pH where it can be mixed with CaffeLatex) suggest you do so with the valve at 12 o'clock.

 

[Yellow Saddle]

Cheers, yeah did read a lot of the reviews, then other products were mentioned so as usual got lost in a world of different sealants!
I like the idea of putting some in before the dreaded puncture, particularly as my tubs are "used", the rear has several small cuts in the tread.

Cut in the thread are not a problem. The chances of a sliver of glass finding the cut at the right angle at the exact moment when the cut is over it, are lottery-win slim. Cuts are only a problem if the casing cords are cut. Then the tyre herniates and produces a blobby ride.
cuts should be inspected with a sharp metal instrument for embedded glass though. The instrument has to be sharp and hard so you can feel the gritty glass if there is any in there.

 

[Yellow Saddle]

If you're going to run with sealant from the offset make sure any sealant you're carrying is of the same brand. Introduction of latex solution form a different manufacturer, and as such possibly a different pH, can kick start polymerisation. Also, some manufacturers don't agree that it isn't the cold shock that starts the latex coming out of solution so if using CO2, Effetto Mariposa (who make Espresso latex repair cartridges - and make it specifically at a pH where it can be mixed with CaffeLatex) suggest you do so with the valve at 12 o'clock.

I've heard that temperature argument before and disproved it with a simple experiment.
Further, the ball forms anywhere in the tyre, not at the valve, nor do you find a layer of congealed latex on the inside of the tyre directly opposite the valve.

 

[Cuchilo]

Theres one way to find out whats just stories and whats the truth

 

[Justinslow]

Cut in the thread are not a problem. The chances of a sliver of glass finding the cut at the right angle at the exact moment when the cut is over it, are lottery-win slim. Cuts are only a problem if the casing cords are cut. Then the tyre herniates and produces a blobby ride.
cuts should be inspected with a sharp metal instrument for embedded glass though. The instrument has to be sharp and hard so you can feel the gritty glass if there is any in there.

I've had tiny pieces of Flint in cuts in my Ultremo zx clinchers particularly in the wet, the cuts were already there, but the flints find them!

 

[Hacienda71]

I've had tiny pieces of Flint in cuts in my Ulttemo zx clinchers particularly in the wet, the cuts were already there, but the flints find them!

You better buy a few lottery tickets then.

 

[Justinslow]

You better buy a few lottery tickets then.

I DNF'd in my last club TT of the season last year for exactly this reason, tiny Flint in a tiny cut in the wet , and had driven back 2 and half hours from a family holiday to compete had 2 or 3 actually over the months (although not in TT's), eventually lost faith in the tyre and replaced it after that TT.

 

[Cuchilo]

Just got back from the LBS where we inflated a tub to 160 psi and then stuck a bradawl in it so it had a rather nice puncture 3 - 4 mm . I had put a bit of pitstop in the tyre and that didn't do a lot of good but it didn't fly out everywhere . We then emptied the rest of the pitstop into the tyre and inflated it to 120 psi . A bit of pitstop came out of the hole like a worm poping its head out of the ground but that was it .
Now home and inflated the tyre again to 120 psi and although air is still escaping its slowed right down . Still no pitstop everywhere which is rather disappointing .