Tubeless Sealant Guide

Tubeless Sealant: What I’ve Learned Running It for Three Years

Tubeless setup has gotten complicated with all the sealant brands flying around. As someone who switched to tubeless on my mountain bike, then my gravel bike, then everything else, I learned everything there is to know about what actually matters and what doesn’t.

What Sealant Does

Liquid inside your tire that plugs punctures automatically. Small thorns, goatheads, glass shards – they punch through, sealant rushes to the hole, particles and latex combine, hole seals. Usually happens so fast you don’t notice anything.

The magic is that this happens while you’re riding. No stopping to patch tubes, no CO2 cartridges, no walking home. Punctures that would have ended a ride become non-events.

How It Actually Works

Probably should have led with this section, honestly. Sealant is basically latex (natural rubber liquid) with particles mixed in. Different brands use different particle types – fibers, crystite, proprietary compounds. When air escapes through a hole, it pulls sealant toward the leak. The particles aggregate, latex dries quickly in air, a plug forms.

Bigger holes need more particles and take longer. At some point – usually around 6mm – the hole is too big to seal and you’re dealing with a flat anyway. But for normal punctures, it works remarkably well.

Brands I’ve Actually Used

Stan’s NoTubes: The original. Works well for small punctures. Needs replenishment every 2-3 months. Doesn’t handle big holes as well as some alternatives. Still the most proven option.

Orange Seal: Seals larger punctures better than Stan’s in my experience. The Endurance formula supposedly lasts longer. I’ve run it for 4 months between top-ups.

Muc-Off: Pink, which makes it easy to spot leaks. Worked fine but nothing special. The color is the main differentiator.

Finish Line: Budget option that works adequately. Seals small stuff, struggles with bigger punctures. Fine for road riding where massive thorns aren’t the threat.

What Matters When Choosing

Sealing ability: Can it handle the punctures you encounter? Road riders rarely get big holes. Mountain bikers in desert thorns need aggressive sealant.

Longevity: How long before it dries out? Three months is typical. Some claim longer. It matters if you hate maintenance.

Compatibility: Does it work with your tires and rims? Most do, but some tire/sealant combinations cause problems. Carbon rims specifically recommend certain sealants.

Clean-up: Some sealants dry into rubbery clumps that are easy to clean. Others turn into a mess. This matters when you eventually need to change tires.

How Much to Use

About 2 ounces for road tires, 3-4 ounces for gravel, 4-6 ounces for mountain bike. More isn’t necessarily better – excess sealant adds rotating weight and sloshes around. Less might not seal effectively.

Err slightly high if you’re paranoid about flats. Err low if you’re a weight weenie.

Maintenance Reality

Check and top up every 2-3 months. Just remove the valve core, add an ounce or two, reinstall. Takes two minutes.

In hot climates or dry storage, sealant dries faster. Cold weather slows it down. Adjust your schedule accordingly.

Shake the bottle before adding. Settled sealant separates and the particles matter.

When Sealant Fails

Big cuts – sidewall slashes, huge gashes – won’t seal. Carry a bacon strip plug kit for these.

Old, dried-out sealant won’t seal fresh punctures. This is why maintenance matters.

Bead burps (tire unseating momentarily) lose pressure faster than sealant can react. Usually requires reseating the bead and adding air.

Worth the Hassle?

That’s what makes tubeless endearing to us riders who hate stopping for flats. For mountain biking, absolutely. The puncture protection is genuinely useful and the lower pressure advantage improves traction and comfort.

For road riding, less clear. Punctures are rarer, the weight savings vs tubes is minimal, and the setup can be finicky. Still worth it if you hate changing flats.

For gravel, definitely. You get road-bike-like efficiency with mountain-bike-like puncture resistance. Perfect match.

Once you’re used to the maintenance routine, tubeless with sealant becomes invisible – you just ride without worrying about flats. That peace of mind is valuable.