Stan's NoTubes Sealant Review
The problem with tubeless tires is that, while they eliminate pinch flats, they still suffer from punctures (like if you get a thorn or shard of glass stuck in them.) Then the tire will need repaired in order to fix the leak...
Unless you have a scoop of Stan's sealant in the tire! This sealant is supposed to instantly seal any punctures in tubeless tires so you never have a problem with punctures up to 1/4" in diameter.
Pros: It works flawlessly. You can get a bunch of thorns or glass bits stuck into your tire, and when you pull them out, the sealant plugs the hole.
Fixing a leak takes no effort on your part - the Stans sealant does all the work.
Cons: Eventually, the sealant will dry up, and you will have to add more to the tire. This only needs done every 3-4 months, though.
The only real problem I have faced is that the sealant will sometimes clog your presta valve, making it difficult to air up the tire.
What happens is, some sealant gets onto the valve, then dries like glue. You might need pliers to free the valve to add air!
The Final Word
If you run tubeless tires, the choice is simple - use Stan's Sealant. It works great and it's a much better choice than Slime or any other competitor.
It's one of my all-time favorite bicycle-related products! I don't know what I'd do without it!