Simply the most effective sealant available
Stan’s No Tubes Race Sealant is expensive, but contains twice as many sealing crystals and uses bigger particles that can make larger holes air tight.
Latex-based and natural, Stan’s is one of the first and best-known tyre sealants. Its popular original formula is proven to work without the familiar issues of drying out prematurely or simply not being able to plug small holes and rips in damaged tyres.
Its sealing properties are so potent; it needs to be poured directly into the tyre, rather than through the valve, as it quickly clogs valve cores.
Race formula is only available in bigger tubs (just under a litre for just over thirty quid), but the extra price over No Tubes standard sealant is a worth it since it’s worked extremely well for me on multiple occasions; plugging big holes fast before I’ve lost all air, which is something that rarely happens out on the trail with other sealants.
The price is higher then, but reflected in superior performance. This is simply the most effective sealant I’ve used in the real world where tyres often get pierced in awkward, harder-to-seal places (like next to the bead, rather than on the crown), and where changing temperatures and difficult to seal holes play havoc with many rival formulas.