Finish Line went all-in on its new tubeless tire sealant, promising an everlasting formula that won’t clog valves and will last the lifetime of the tire. Comprised of Kevlar strands with zero ammonia, Finish Lines sealant claimed to patch the tire carcass, stopping leaks through Kevlar, but does it?

Check out the exciting claims HERE.

Does not clog the valve

Easy to install

Did not work as claimed

Could not seal a 2mm slice

Messy when installing tube after failing to seal





When Finish Line dropped the news about its groundbreaking sealant, the cycling world was abuzz with wonder. Not having to deal with cleaning valve cores and checking declining sealant levels in tires; tubeless users rejoiced. Finish Line’s formula consists of a Kevlar mix that is claimed to repair or heal the tire carcass, leaving no mess and quick action. When a puncture happens, fibers rush into the wound and quickly stop air loss. Harnessing DuPont Kevlar fibers, FiberLink seals are said to be sturdy and flexible once they surround a leak. As the tire rotates and flexes while it’s ridden, the FiberLink mesh tightens and reinforces itself, creating an airtight seal that is said to last the life of the tire. Since there is no liquid latex or ammonia in Finish Line sealant, it’s non-toxic, hypoallergenic and safe for carbon fiber rims.

Install of the Finish Line Sealant is similar to others on the market, except no shaking of the bottle is required. Particles are suspended in a fluid, evenly spaced throughout the tubeless liquid. I did have to cut the top of the applicator to inject the sealant via the valve core but all in all; painless and clean. From the bottle’s recommendation, I installed 5 ounces of Finish Line Tubeless Sealant; this amount is said to protect a 29-2.3 tire from punctures and flats. I used the Finish Line sealant with tires that I have personal experience with and have had success with other sealants and punctures. For this test I chose: Vittoria’s Mezcal 29-2.25 TNT-Casing and IRC Serac X-Guard Sand CX Tire 700-33; Tires with sturdy sidewalls and regular in my rotation.

My first flats were on the Vittoria Mezcal while riding rocky terrain. The cut, a less than 2mm puncture should have sealed while riding but did not. I found myself on the trail side going through multiple CO2 cartridges trying to help seal it. The leak would seal for a second or two, and then would break open, and I was flat again. After multiple attempts and massive air loss, I succumbed and went for the tube. Installing a tube after Finish Line sealant is a messy job and required the sacrifice of my gloves to ensure proper installation. Arriving home after my ride, I cleaned out the remaining Finish Line sealant and installed Orange Seal Endurance to see the difference; the puncture sealed and has yet to go flat.

The IRC Sand suffered a similar fate with a smaller “snake-bite” style puncture. After numerous attempts to seal the holes, a tube was installed in a messy, roadside battle.

I had very high hopes for the Finish Line tubeless Sealant, but after testing and many flats, I’m not a believer. I like the idea of a Kevlar style sealant that will not clog valve cores and will last a lifetime of the tire, but I don’t believe this is it.

Rating: 2 out of 5

Price: $15 for 8 oz bottle





More Info: www.finishlineusa.com