Break the bead, pour it in, and forget about flats for the day — that's the whole idea behind Race Day Tubeless Sealant from Stan's NoTubes. This is the racing version of the sealant that started the tubeless movement, and Stan Koziatek spent years refining it for the mechanics working pro pits before it was released to the public. The formula starts with the same latex base as the Original sealant, then piles on the puncture-fighting hardware.

The difference is in the crystals.

Where the standard formula relies on a single particulate mix, Race Day carries 200% more sealing crystals and adds oversized XL crystals that aren't used in the regular version. When you take a hit, the large and small crystals interlock into a lattice over the puncture, sealing it and reinforcing the surrounding area. The payoff is faster sealing and the ability to plug larger holes — the kind of cut that would otherwise end your day or your race.

Here's the catch you need to know before you buy: this sealant cannot go in through the valve. The volume and size of the crystals will clog an injector or valve core almost instantly, so you have to unseat one side of the tire bead and pour it directly over the rim. That also rules it out for topping up through the valve later — plan on breaking the bead when you refresh it. It's the tradeoff for the sealing power, and it's why this is a race-and-event sealant rather than a set-and-forget one.... Read More