While not universally accepted (yet), the benefits of tubeless tires have always attracted riders, and Silca Ultimate Tubeless Sealant promises to be the best tubeless sealant on the market, thanks to a novel combination of materials and a system that prolongs sealant life through intermittent replenishment of latex and solvent. system, which promises to be the best tubeless sealant on the market.

Tubeless sealants typically consist of natural or synthetic latex, a solvent to prevent drying, and often small particulates to plug holes. The less solvent, the more goo the tire will have, but it will dry quickly. Less solvent will make the sealant last longer, especially in dry environments, but there is a risk that the holes will not seal very well.

Silca Ultimate Tubeless Sealant, like other sealants, is a mixture of latex, solvent, and fine particles. The particulates in particular are different. Previously, old carbon frames and components were destined for landfill, stubbornly resisting decomposition for thousands of years; Silca decided there was a better option: grind them up and mix the fibers into a modern tubeless sealant.

The addition of particulates varied from the sparkle of microplastics to fiberglass to natural materials like walnut shells and cornmeal, so it was only a matter of time before carbon fiber was added to the tubeless sealant.

The frame is crushed and ground into individual fibers. Then, through a proprietary process, the epoxy resin that binds the fibers of the bicycle parts together (and makes the fibers less likely to break down) is removed. The process remains a mystery, but the resulting electron microscope images prove that it is a very clean carbon fiber. The combination of carbon and natural latex creates a sealant that can be blown off the sidewalls and ejected into the environment with no damage, except for a short period of unsightly spattering of the tire's interior.

The fact that it is a natural material is of course laudable, but if the material does not work, it is of little use.

Carbon fiber is famously light and stiff. That's why many of the best road bikes use carbon fiber, but it's also why, in theory, it can add excellent suspended particulate matter as a sealant in tires. Smaller mass means that more can be suspended in latex and solvent without settling or solidifying, and harder means that they can more easily fill holes and cracks, whereas air pressure pushes sealant out of holes. Silca claims that its Ultimate Tubeless Sealant can plug holes up to 7.5 mm by mixing fiber lengths.

In other words, it can seal the best gravel tires even after hitting a sharp flint, but that's only half the story. As mentioned earlier, if the sealant dries out in two weeks, it will not seal at all. Instead of replacing the sealant regularly, we should first inject the Ultimate Tubeless Sealant into the tire (not through the valve, since injecting through the valve will clog it), then use the Ultimate Tubeless Sealant Replenisher (this time through the valve, since the sealant will not seal the tire), then use the Ultimate Tubeless Sealant Replenisher (this time through the valve, since the sealant will clog the tire). This replacer is essentially a sealant minus the fibers, with a little more solvent to refresh the fluid inside that has not yet completely dried.

Since 25mm tires do not require as much sealant as 2.7-inch mountain bike tires, Silca sells Ultimate Tubeless Sealant in 8oz, 16oz, and 32oz bottles for $18, $24, and $38, respectively (about 14 lbs, 18 lbs. and 29 lbs.). Replenisher is available only in 4 oz. bottles, retailing for $12 (about 9 lbs.) each.