18th September 2019 / Comments (3)

Squirt SEAL Tubeless Tyre Sealant

Squirt Seal Tyre Sealant

We are big fans of tubeless tyres here at ADVNTR. Most of us have been running tubeless for over a decade. Having started out with messy, home-brew ‘ghetto’ conversions with often hilarious consequences. Yes, it is fair to say we have gone through our fair share of tyre sealants. So, when we get news of a sealant we haven’t tried, we like to check it out. A few months back we were contacted by Squirt Cycling Products, a brand better known for its wax based chain lube. With it’s new Squirt SEAL, the South African company claims to solve the issues of drying out prematurely or simply not being able to plug small holes and rips in damaged tyres.

Bead Block What?

A special mixture of propylene glycol and rubber latex work to plug smaller holes. If the hole is too large, the mixture of fibres and the unique ‘Bead Block’ particles are designed to work together and block holes up to 6mm. The USP with Squirt SEAL is this Bead Block stuff which is part of the standard mixture. An additional bottle of Bead Block is included with the larger bottles of SEAL, enabling you to customise the mixture according to the conditions they are riding in. Going somewhere flinty and with a high chance of punctures? Add more Bead Block to the mix. I’ve come to describe the solution as the ‘Salt n Shake’ of the tyre sealant world.

The standard mixture is perfect for everyday riding. But if you are going somewhere puncture prone and need that extra protection, pour in some extra Bead Block. Think about the Dirty Reiver and the huge attrition rate of riders taken down by punctures. Load your tyres up with an extra dosage of Bead Block and you can be a lot more confident that you won’t be one of them guys!

Squirt Tyre Sealant bottles

Before we delve further, lets look at what Squirt say about this sealant. From their website:

  • Ammonia Free
  • Longer lasting
  • Seals punctures from objects with a 6mm diameter
  • Will not dry out prematurely or permit tyre walls to stick together
  • Suitable for use from -20 °C to 40 °C

The setup bit

Squirt Cycling Products sells the SEAL Tubeless Sealant in two sizes: 150ml, a 1 litre bottles. A 5 litre workshop version is also available if you have a real sealant obsession. The 1 and 5 litre bottles contain the Bead Block particles in a separate, smaller bottle, so you can customise the solution. Why not just pour all the Bead Block in the solution anyway? It’s a question of longevity and uniform mixing of the Beadblock. The little crystals bulk up the mixture, making it more effective against large cuts and abrasions, but the flip side is it dries out quicker if you add more than the standard recommended amount. Squirt tell us from their experience, the standard solution can last up to 7 months before drying out. Modifying the mixture with extra Bead Block will reduce this significantly, but you can seal bigger punctures.

There’s no specific way of adding the sealant to the tyres. The 150ml bottle comes with a tube applicator so that you can pour it in through the valve by just removing the core. With the larger bottles, Squirt assume you’ll either have an applicator on some description lying around your shed. Otherwise, it is just a case of pouring the solution into the tyre before fully seating it to the rim. With the likes of Weldtite and Muc-Off including novel application methods with their sealant, Squirt’s approach feels much more DIY. I took to applying the sealant through the valve with a large syringe to avoid any mess.

Squirt SEAL has a unique sound in the tyre, like wet sand sloshing around. The Bead Block crystals are the culprit for the sound effects. The sound provides a very easy way to gauge if you need to add more sealant to your tyres. Once the tyres are spinning, the sound goes away, so you won’t have to worry about sounding like a runaway cement mixer on the trails.

Out on the trails

Of course, no fancy features such as Bead Block matter if the sealant is not doing its job. In the case of Squirt SEAL, it does its job quite nicely. Most of my testing over the past 3 months has been with the standard solution, with no additional Bead Block additives. The performance was at best, very similar to other leading sealant brands. Sealing up things quickly and efficiently whenever the inevitable sharp thorn or flint pierced my tyres. It is in the same league as Stan’s or Orange Seal in many ways.

From experience, wet conditions can really hamper the performance of a tyre sealant. Rain and puddles can dilute the mixture, even wash it out before it gets a chance to plug a hole or cut. Unfortunately it is usually on wet rides where punctures are more commonplace, torrents of water deliver plenty of sharp objects onto the roads and trails! Luckily Squirt SEAL didn’t seem to struggle as much as some sealants in the wet. The performance is definitely hampered, taking longer to work, but it never once failed.

Squirt SEAL tyre sealant


Only once did I have a ‘major puncture’ experience where Squirt SEAL struggled. A flint managed to put approx 5mm slash into the centre tread of a Panaracer GravelKing and failed to fully seal the hole. The solution would plug it for a short distance before opening up again and spurting sealant for a few more revolutions. This went on for a couple of miles before I resorted to using a tyre plug. Once the hole was given the anchovie treatment, Squirt SEAL went back to doing its job with success. Following the ride I topped up the sealant with an added dose of the Bead Block particles for safe measure. I can’t accurately say whether they helped, but no further punctures were experienced throughout the rest of the test.


During our tests, the sealant performed well. Never once letting me down to the point where an innertube was needed to keep me rolling. My findings are far from a detailed lab test and are just from riding experience. And like all sealants, a lot of it working right is down to the tyre and simply pure luck! That said, I’m impressed with the performance of the Squirt SEAL. The price is higher than many other brands, but it is a very effective sealant.

Squirt SEAL is available through Sigma Sports in the UK. You can also find it on Amazon via Squirt UK.

Squirt SEAL Tyre Sealant

£9 (150ml) £34 (1 litre)

A reliable tyre sealant that does exactly what it should: Seal!



  • Seals fast
  • User can define the thickness with Bead Block additive
  • Easy to wash out of old tyres


  • Installation can get messy

Last modified: 26th September 2019

3 Responses to :
Squirt SEAL Tubeless Tyre Sealant

  1. Martin says:

    My last cat died of ethylene glycol poisoning. Very distressing. Ethylene glycol is extremely toxic to cats – it does not take much. I would not go anywhere near a product containing the stuff if I can avoid it. I don’t have much choice in my car’s engine coolant. But bike tyres? Thanks, I’ll pass.

  2. Chemist says:

    If I am correctly interpreting the review the sealant contains propylene glycol. Propylene glycol is food safe, while ethylene glycol is not.

  3. Martin says:

    Opps – my bad. Misread it; propylene glycol, not ethylene glycol. Cats are safe! 

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