How Tubeless Tyre Sealants Work and what are formulations?
Since the advent of Tubeless Tyre Sealant technology, latex based sealants have been the most common option. While they are great at sealing punctures, they tend to dry up over time which requires periodic cleaning and re-filling. Recently, there have been several new options popping up making claims that their sealant will never dry. The current liquid, latex-based standards are fantastic, but if the new sealants require less maintenance, it could be a game changer. I decided that I wanted to test out some of the new competition against the trusty standards to see how they hold up over time.
In this test, we were sent shop size samples from four different Tubeless Tyre Sealants companies. I used a different sealant in four different tires, each ridden between 50 to 100 miles per week. The test was done over a period of four months to see how well each sealed punctures, but also to see how they hold up to their marketing claims. I set up each tire using the instructions provided by the manufacturer. I also unseated each tire once a month to check sealant levels. In the end, I never faced any massive punctures or cuts, but each tire did see many small punctures during the test.
Once installed, the Tyre Sealant forms a protective layer inside the tyre. When a puncture occurs, the internal pressure of the tyre instantly pushes the sealant into the cavity. The special fibres and mica particles accumulate and bond to the rubber in the cavity. A solid rubber plug is formed through the full depth of the puncture hole. This forms a more secure and superior repair than a traditional plug that is inserted from the outside of the tyre. A traditional repair further expands the puncture and tears the rubber bond of the tyre. A tyre sealant plug is a more natural repair, as the mica/rubber particles and fibers closely mimic that of the tyres rubber.
Why does the Tubeless Tyre Sealants in the tyre remain viscous while the plug is solid and permanent?
The glycol is the carrier of the fibres that form the solid plug. Contracting and expanding of the cavity due to the tyres normal behaviour, squeezes the glycol from the plug. This allows the fibres, mica and thickeners to bond and form a solid plug. The remaining solution in the tyre continues to coat and protect the tyre from hundreds of punctures.
Tubeless Tyre Sealants are a balanced formulation of glycol, organic thickeners, binding agents, mica, rubber particles and cellulose fibres of different types and strength. The water based glycol is the liquid carrier of the solution that suspends the solids. The mica particles and fibres, which vary from ceramic, wool and aramid (Kelvar), determine the strength of the solution.