Black Ox Tire Sealant Review


Words & Photos by Mike Wirth/Ride Goosed

Modern tubeless systems all use a sealant of some kind to plug the tiny holes and imperfections that can allow air to leak over time. Most all of those sealants use a latex formula with some kind of particulate, which also allows the liquid to travel to the hole, and then evaporate to leave the particulate in place to plug the leak, and hopefully let you continue merrily on your ride. However, any rider who’s been trailside after smashing their tire into the business end of a sharp rock and pleading with the fountain-spray of latex from the sidewall tear that it, “PLEASE JUST SEAL UP!!!”, knows the value of a quality formulated sealant.

Black Ox is a tire sealant that claims “superior sealant” properties, thanks to its Carbon Fiber Enhanced formula. The notion to formulate a better sealant came when the Black Ox team mechanics witnessed a top sealant brand fail during a National Championship race that cost them a title. Following that mishap and months of lab work and trail testing, Black Ox sealant is now available to any rider who hates dealing with flat tires and sealant that just won’t seal.

Black Ox sealant is made right in the good ol’ US of A at their North Carolina facility. The formula uses a latex base that looks quite similar to any other sealant, but with a chunkier texture. Those extra bits of particulate are actually strands of carbon fiber, and are what Black Ox claims make it better at sealing large holes and sidewall tears. These fibers still work well with standard install methods, making it possible to install Black Ox through the valve stem like any other sealant.

Black Ox claims their product has a shelf life of about a year in ideal conditions, and works in temperatures as low as 20º F. The sealant is available in single use 4-oz bottles, or in 16- and 32-ounce bottles for the garage.

Black Ox Tire Sealant Review

There’s nothing worse than having a National Championship race run end in crushing disappointment because of a mechanical failure. That is, unless that same failure that flicked you off the podium also left your bike and gear covered in the same sticky, shi**y sealant that was supposed to carry you across the finish line. But that’s exactly what happened to the Black Ox crew. And damned if they didn’t make sure that was never going to happen to them again.

We are not going say that this stuff will seal every puncture you get on the trail. But since we started using this stuff on our SoCal fleet of four test bikes, we have had positive results. During that time, we’ve noticed a handful of punctures. One of them was an unknown puncture that plugged before we even stopped, and all we had to do was pump up the tire and continue our ride.

The second went totally flat on us trailside, but eventually sealed after inflating it several times with a hand pump. The third was a full sidewall tear that, while we had to patch from the inside at home for a permanent solution, was still able to hold about 15psi to limp home on our bike. As a final show of its sealing strength, when we went to refresh the supply in our tires after a few weeks, we found the syringe tube we used to squirt it into the valves had sealed itself shut permanently. Yeah, this stuff likes to plug holes.

Black Ox Tire Sealant Review

The Wolf’s Last Word

We used the 32-ounce bottle of Black Ox to outfit a fleet of four bikes for the summer of SoCal desert testing, and that means many encounters with trail sharps of all kinds. While any sealant has its limitations, Black Ox has yet to leave us stranded or even forced us to reach for our emergency tube. That’s a successful test in our book. The same bottle, which is still almost 1/2 full, is every bit as capable of plugging air holes, or more so, than any other brand we’ve tried. We’d be willing to trust this stuff when the air in our tires means the difference between winning or losing, or even just making it home without having to battle a trailside flat tire debacle.

Price: $5.99 – $27.99;

We Dig

Seals small punctures with ease
Works well enough on small sidewall tears
Saved three rides successfully

We Don’t

Clumpier texture clogged our syringe tube to install through valve


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