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Aug 14, 2023

Tubeless Sealant CareTips

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. How we test gear. Tubeless sealant has a limited useful life. Here's how to clean out the old and

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. How we test gear.

Tubeless sealant has a limited useful life. Here's how to clean out the old and add fresh juice for optimal performance.

As the pile of snow in front of my house shrinks, I’m starting to prep my bikes for the riding season. In addition to cleaning, lubing, and replacing worn parts, one of my biggest and most important projects is refreshing the sealant inside my tubeless tires.

Sealants, especially latex-based sealants (most tubeless bicycle sealants are), have a limited lifespan. They simply dry out (evaporation caused by the environment as well as pumping air into the tire), or the latex and aggregate (the chunks that help clot holes and cuts) stick to the tire’s casing and leave behind water. In either case, the primary function of the sealant—sealing holes on the fly so you can keep riding—becomes severely compromised.

In my experience sealant dries faster in warmer and drier climates and lasts longer in cooler and wetter climates. This isn’t surprising because all sealants (that I know of) contain a high percentage of water. Where I live, in the Four Corners region of Colorado, I’ve found the best practice is to check the sealant every 30 days or so. It doesn’t matter if I’m using an ultra-sticky “race sealant” or something that’s advertised as an “endurance” sealant: I check it every month.

The best way to check the condition of your tubeless sealant is to pop a short section of the tire’s bead off the rim and visually inspect the inside of the tire.

Rotate the tire so the open section is at the six-o’clock—so the liquid pools in sight—and look at the sealant. If the sealant looks fresh—somewhat thick and opaque—and there’s plenty of it, you’re probably good. If the sealant is dried out, looks low viscosity(like dirty water) or if the sealant looks okay but there’s not much of it, it’s time to move to the next steps.

A lot of times, all that’s needed is to add a little more sealant inside the tire. Sealant is heavy, and also the dreaded “rotating weight” so I understand the urge to try and use as little as possible. Fight this urge and use plenty: The sealant will work better and will have a longer useful life. I almost always use more than the recommended amount.

It’s best to refresh with the same sealant originally used inside the tire. Some sealants react to each other which can compromise their performance.

Many sealants are non-toxic and eco-friendly (always follow the manufacturer’s disposal information) and can be cleaned out with a rinse of water, or simply wiped out with a rag. Other times, you’ll need to remove the tire, turn it inside out, and use a gentle scrub brush to clean off the dried old gunk. Use a plastic putty knife to free thicker clots of stubborn dried sealant.

Silca and Effetto Mariposa make sealant removers, though I’ve not used enough to comment on their performance.

Note that if you have a latex allergy (like I do), it’s best to do all this work wearing a pair of heavy-duty nitrile gloves. Also, it is a good idea to put a set in your road/trail repair kit. Alternatively, you can use one of the latex-free sealant options.

Once you clean out the old stuff, it's time to remount the tire and add fresh sealant. In my experience, the most foolproof way, and the best way to limit mess, is to break this process up into a few steps.

First, mount the tire completely without sealant. Then remove the core from the valve stem. This lets more air rush into the tire more quickly, increasing the chances of the tire inflating and locking into place.

Inflate the tire (don’t exceed the tire or rim’s maximum pressure) until the beads fully seat: This is usually announced with several disconcerting pops. If the tire won’t seal or fully seat, I’ve found a solution of diluted dish soap helps things along.

Remove the air chuck—all the air will rush out, but the tire should remain fully seated. If you’re using a thinner sealant with light aggregate—Stan’s No Tubes original and Orange Seal Regular are examples—you can inject the sealant through the valve stem. Blow the excess sealant out of the valve stem (so it doesn’t gunk up the core), install the core, and inflate the tire.

Note: This is a good time to replace your valve cores. Over time, cores get clogged up with dried sealant. This limits airflow into the tire or prevents them from fully sealing, causing leakage. You can scrounge spare cores from old tubes (if they have removable cores), but I like to keep a handful of spare fresh cores around so I can replace them as needed. Alternatively, you can invest in new-school valves made specifically for sealant that never clog like the Reserve Fillmore or the 76 Projects Hi Flow.

If you’re using a thicker sealant or one with a lot of aggregate—examples include WTB’s TCS and Specialized RapidAir—an injector will not work well. These sealants clog the injectors, or the injector’s opening prevents aggregate chunks from getting inside the tire.

Instead, unmount a short section of the tire from the rim and pour the sealant directly into the tire. You can either wing it or measure it out with a scoop: I typically use recycled drink mix scoopers to measure out sealant. Remount the tire, install a core—replace with a fresh one if needed—and inflate.

However you get the sealant into the tire, once it is inflated, be sure to spin the wheel and flip it in every direction so the sealant touches all parts of the casing.

I’ve tried a lot (A LOT!) of sealants, and most are acceptable. My current favorites are good ol’ Stan’s No Tubes, Silca Ultimate, and WTB TCS. And I like those sealants for everything: Road, gravel, ’cross, and mountain.

Sealant enhancers are also a thing. Silca’s replenisher is compelling because it’s specifically made to extend the life of its excellent sealant, but I have yet to use it long enough to comment on its performance/

Sealant enhancers are another additive. These contain aggregate material that, it is claimed, improves sealant performance by sealing holes quicker and helping the sealant plug larger holes. Effetto Mariposa makes some for its sealant, while Hold Fast Cycling’s Highland Dust is made to add to any sealant. Hold Fast also sells Muc Off sealant premixed with its Highland Dust.

A gear editor for his entire career, Matt’s journey to becoming a leading cycling tech journalist started in 1995, and he’s been at it ever since; likely riding more cycling equipment than anyone on the planet along the way. Previous to his time with Bicycling, Matt worked in bike shops as a service manager, mechanic, and sales person. Based in Durango, Colorado, he enjoys riding and testing any and all kinds of bikes, so you’re just as likely to see him on a road bike dressed in Lycra at a Tuesday night worlds ride as you are to find him dressed in a full face helmet and pads riding a bike park on an enduro bike. He doesn’t race often, but he’s game for anything; having entered road races, criteriums, trials competitions, dual slalom, downhill races, enduros, stage races, short track, time trials, and gran fondos. Next up on his to-do list: a multi day bikepacking trip, and an e-bike race.

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