I’ve been doing a tour of different tubeless sealants recently, for a couple of reasons. One is that most of them dry out too quickly for my tastes. I recently ordered a big jug of Finish Line’s Fiberlink sealant and I may have finally arrived at a sealant that I will stick with.
Fiberlink uses a low-viscosity latex mixture that includes kevlar fibers to help seal any cut or puncture. The original formulation of Fiberlink didn’t work quite as advertised and Finish Line reformulated it and reintroduced it not too long after it was introduced.
I don’t puncture that often, but I’ve experienced two small punctures with Fiberlink sealant in the tires and in both cases and I’m pleased to say that I didn’t find out about the punctures until after I got home. Putting away my bike, I looked down to see a buff-colored mark on the tire and then realized that it was dried sealant.
It comes in three sizes: an 8-oz. bottle, a 32-oz. bottle and the 1-gal. jug. and the way it’s priced, buying larger amounts is really worth it. Also, I can say that it keeps in the bottle quite well. I misplaced a half-used bottle for almost six months and it was still perfectly good when I ran across it.
One quality that I prize in sealant is the ability to use the Milkit syringe to inject sealant through the valve stem without it gumming up the valve and valve core—even though I remove it to use the syringe. I have yet to come across a more cooperative sealant in this regard.
Final thought: There may be a better sealant out there, but I can say that Fiberlink is the least-frustrating sealant I’ve used so far.