24th June 2019 / Comments (0)

Squirt Cycling Products Tyre Sealant

Squirt Tyre Sealant bottles

In the beginning there was Stan’s.

Not so long ago, if you wanted tyre sealant you had a choice of Stan’s in a large bottle, or Stan’s in a smaller bottle. At least that is how it seemed.

Nowadays, the choice is overwhelming and for a lot of us, the easiest option is simply to buy whatever your local bike shop sells.

From a consumer’s perspective, it does not help that most sealants seem to be remarkably similar! But if they all more or less work, where is the problem? This argument is perfectly valid  but, as riders start to push the performance envelope of their bikes (particularly gravel bikes), you have to accept there is a need for something more robust, more likely to keep you out of trouble in the wilderness. This will seem most obvious when your sealant fails and you are miles from any help.

How then, do you choose the sealant best suited to your own particular needs? Do you spend time and effort researching or just go with the default option? And how can you be sure you have chosen the right one?

Taking all this into account. Although consumers have generally become accustomed to a degree of homogeneity within this product line, if someone claims to have something that could turn the whole sealant world upside down….it would be rude not to investigate.

And this is where Squirt Cycling Products enter the story.

Squirt Cycling Products Tyre Sealant

Pttisssssshhhhhh. Not this time!

Graded grains…

Squirt Cycling Products got in touch with us following recent articles about tyres being torn to shreds on flint strewn trails. They thought their new sealant could solve all our problems and that perhaps we might care to try it out. Forgive our initial scepticism, but we expected yet another take on the #MeToo sealant range and were not that enthusiastic to start with. It was not until we had a chat with James Hinsby from Squirt Cycling Products however, that we felt they probably did have an innovative product and that we ought to sit up and pay attention!

Squirt Cycling Products Tyre Sealant on test in the Moors

Our testing of the new Squirt Tyre Sealant has been done in various terrains and different tyres.

Sealant – a simplified theory

The theory behind sealant goes something like this.

In every bottle of tyre sealant, the fluid is made up of different components :- the liquid (carrier milk) and the fibres or particles.

The carrier milk acts principally as a transport device for fibres and particles  – the stuff that actually ‘mends’ the puncture. Its also has a secondary role as the primary sealant for small punctures. If you get a pin hole flat for example, it will probably be the latex in the carrier milk that sorts it out. Larger holes however,  are dealt with by the fibres or particles that are carried, as a sort of suspension, in the fluid.

The whole process is similar to blood clotting with the latex and particles replacing fibrin and platelets in closing off a wound/mending a puncture.

However…Particle Theory

Just when you think you have got your head around this relatively simple concept, it gets more complicated. It is not just the particle volume (size) that you have to worry about. Particle density (mass) is equally critical. Get the density wrong, and your particles will either want to float on the carrier milk or fall out of suspension. Predictably, neither option is that suitable for sealing a puncture!

Squirt Tyre Seal

Squirt Cycling Products Tyre Sealant shown here in 1 litre and 150ml bottles

And then there is the danger of blocked valves. Get the particle bit wrong and you risk blocking up the valves. I had to dig crystallised sealant out of a valve this weekend as I could neither inflate nor deflate the tyre even with the valve core removed! It is not a massive job but it is one you really want to avoid out on the trail.

There would appear to be a practical limit to the particle density so you should not be too heavy handed.  On the other hand, you must be careful not to be too sparing either as you run the risk that your sealant stays nice and runny but is useless at filling holes!

So, as you can see, things are slightly more complicated than they might seem. But we are not finished yet!

Milk or cream cheese?

Ideally, the carrier milk will stay liquid for as long as possible, and in as wide a range of temperatures as possible. After all, there is no point in it drying out after a few weeks if it gets sunny for a change. You have to get the solution absolutely right otherwise there can be unexpected consequences.

For example, we have had more than one sealant fail and turn to cream cheese in the last few months.  Not only did it look disturbing, but it did not seal punctures either. This could have been because of a chemical reaction between the sealant and the tyre or maybe the particle density was too high. Whatever it was, the product was useless.

What’s the recipe today Jim?

Whatever the relative proportions of latex, water, fibres and particles in any given sealant, there has been no way for the man on the Clapham Omnibus to fine tune its basic characteristics. Until now that is.

Squirt Cycling Products look set to turn the market upside down with their new sealant. As a generic breed, we cyclists tend to roll over a smorgasbord of surfaces on an equally broad range of tyres. While most sealants work well in a narrow range of situations, what has been missing is the facility to customise it. What Squirt Cycling Products realised is that, while it makes absolute sense to produce a base product like everyone else, the genius is to provide the wherewithal to customise the mix. They do this by letting you adjust the particle density with “BeadBlock”.

This is a potentially ground breaking idea and we really had to find out more. So we contacted James and deluged him with questions.

Squirt Cycling Products Tyre Sealant testing in Yorkshire Moors

Some typical North Yorkshire ‘back roads’ proved a useful test for the Squirt Cycling Products Tyre Sealant…

Squirt Tyre Sealant – the nitty gritty

Let’s address the basics first. Regarding the liquid component of your sealant, can you confirm what it is and whether it performs any roles other than simply being a medium for fibres and particles?

Our sealant uses Propylene Glycol (20-30%), Rubber Latex (15-20%) and Water (40-50%). The water acts as the transport device for fibres and particles but it also carries the Propylene Glycol and Latex. These two components are invaluable in sealing up smaller holes. If the hole is too large, the fibres and particles are next on the scene to do the heavy lifting.

Being realistic here, how large a hole can the standard solution seal?

On the label we say 6mm. I can confidently say that this is achievable with the standard mixture.

OK, so how about the customised version. What difference does it make?

I have sealed cuts that are up to 8mm long. This is where the customisation is so cool. I have been playing around with it a lot, as you can imagine, and achieved these results with two caps of Beadblock.

Are there any (realistic) functional pressure limitations? Obviously, the pressures in a road tyre are going to be far higher than a mountain bike tyre. Doesn’t it just all spray out if you flat your roadie tyres?

I have been running 6 Bar in some Continental 28mm GP 5000s, and the same in Schwalbe 32mm gravel tyres. On my mountain bike I have been running Maxxis Ikon 29er tyres at 1.8 Bar. So far the sealant has performed well in all three scenarios. I am not sure I can say the same about my back though, 6 Bar on a gravel bike is a little harsh!

Now for the $64,000 question. How long does the sealant last in typical UK conditions? All too often you can be left at the side of the trail with a flat tyre because your sealant has dried out. There is nothing quite so frustrating!

Testing the Squirt Cycling Products Tyre Sealant

Not all punctures happen on rocks and flinty trails. Even the most innocent of paths can bite.

I spend most of my time riding in Austria and the UK. I think the climate is roughly comparable, at least as far as sealant is concerned! The longest I have left it between fills is seven months. October 3rd 2018 to mid April 2019 to be precise! I had 120ml and one cap of Beadblock in a Maxxis Ikon. I slashed the outer carcass in mid April, before riding an MTB marathon in Wales, so I had to change it. Once I had got the tyre off, the Beadblock was still there and the liquid was still…liquid!

We have tested Squirt Cycling Products Tyre Sealant all around the World to see how it copes in different climates. In the super hot and dry conditions of South Africa and the USA, it was down to four to five months. Still pretty respectable. It just depends where you are riding.

When it starts to go off what happens? A lot of sealants start to ball up which is far from ideal.

When I took the Ikons off, after seven months of riding, the Beadblock was starting to discolour and go yellow. I also noticed a dry layer forming in the centre of the tyre but it was quite evenly distributed. There was certainly no balling up.

When you take the tyre off, what you will notice first is how ‘clean’ it is inside. There are none of the spiders webs or congealed latex clinging to the inside of the tyre that you often find. This makes it much easier to clean.

Squirt Cycling Products Tyre Sealant

What tyre for… Is a question to answer another day.

Fresh from my time excavating valves I had a killer question up my sleeve. If I was to add Beadblock to the standard solution, surely I am going to run the risk of blocking up my valves.

I have been running two caps of Beadblock in some gravel tyres for three months. If I was going to get a problem with clogged valves, it would have happened by now. All I can say is that having pumped up the tyres a few times, there is no sign of any buildup or clogging.

You really have to experiment to get the best results, but the beauty of the Squirt Cycling Products Tyre Sealant system is that you are in control. If you are happy to risk blocked valves in favour of greater security, you can do so. To reduce the probability of punctures at all costs, simply run a really high ratio of BeadBlock. You just have to understand that you might block your valves. If you want the best of both worlds though, you could invest in some non return valves, like the ones Milkit sell.

As we reached the end of our chat, I had just two more questions to ask. Having recently covered a black T shirt in sealant, I discovered that it is tough to get out of fabric. Knowing that I cannot be the only one to have done this, I had to ask  “How easy is it to get out of clothes?” Why was I not surprised when James told me they had thought of that too?

At the risk of sounding like a set of washing instructions. If you get any sealant on your clothes, first let it dry. Then rinse the garment through with warm water to remove the granules and the worst of the milk. Follow this with a 40 degree cycle in the washing machine (Persil works well it seems) and most of it will have gone. All traces of it should have disappeared after the next wash.

To finish off then James. Lots of companies tell us they have a killer product but reality is somewhat different. How much ‘real world’ R&D have you done and is there any one thing that suggests you are onto a winner here?

We have been testing the current iteration of Squirt Cycling Products Tyre Sealant for just about two years. Riders are using it all over the World for DH, XC, Gravel and on the road. Feedback so far has been very encouraging but I knew we were onto something at the Cape Epic. We took it to the event two years ago as part of a normal R&D program. Word of the sealant got around and last year, 70% of the professional riders used it. We even had to set up a special dispatch office so they could come and pick it up. When that happens, you know you have got it right.

Squirt Tyre Seal - Scope Wheel

Photos of sealant isn’t that exciting. So here’s gratuitous shot of a wheel. Picture the Squirt Tyre Seal sloshing around inside…


This far, my only real gripe is the delivery system.

The instructions recommend adding the basic liquid and BeadBlock into a open tyre. This is fine if the tyre is easy to fit. If it is tight or just difficult to fit, it could get messy and you might need to refer to James’s washing instructions!

Personally, I prefer to introduce sealant through the valve. Both the 1 and 5 litre bottles are obviously way too big. The best thing to do is to buy a 150ml bottle first and use that. Once you have finished it, recycle the bottle and fill it with your custom mix. Not only does it make it easier to inject the sealant, it also means you can create custom solutions in small quantities.

Another option is to buy a syringe, the choice is yours.

Testing at ADVNTR

We have had the Squirt Cycling Products Tyre Sealant for a few weeks now. It really is far too early to give this a proper review. Suffice to say, I have set up a couple of pairs of wheels with Squirt Tyre Sealant. One for gravel and one for the road. While absence of punctures is not evidence of the product working, I have been puncture free so far! That is all I can say!

Meanwhile James completed The Distance in the Lake District without any problems. Loaded up with luggage and rolling on low pressures he avoided any unplanned stops. Signs of latex over his frame indicated that the sealant had been called into action more than once. So it worked!

We will give Squirt Cycling Products Tyre Sealant a thorough test this summer riding up and down our flinty test track and beyond. Look out for my long term review in the autumn.

Lakeland descents

Loaded Lakeland Testing

Squirt Cycling Products Tyre Sealant

The sealant is available in three sizes – prices shown are RRP.

150ml (pre mixed) £9.00

1 Litre (with Beadblock granules separate to allow custom mixes) £34.00

5 Litres (with Beadblock granules separate to allow custom mixes) £98.00

Available from Sigma Sports

Last modified: 31st July 2020

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