You can use CO₂ with some tubeless sealants, but the answer depends on the exact formula in your tyre. Peaty’s calls its Holeshot Biofibre sealant CO₂-compatible. Stan’s treats CO₂ as an emergency option and recommends replacing it with ordinary air afterwards. Those are different instructions, so “tubeless-compatible inflator” is not the whole answer.
For MTB and eMTB riders, a cartridge can be a quick way to recover pressure after plugging a puncture. It is less useful if the hole is still open, the bead has come off the rim or you do not know whether there is working sealant left inside. Start with the leak, then choose how to inflate.
Why CO₂ and tubeless sealant can be an awkward mix
A CO₂ cartridge releases compressed gas through the inflator into the tyre. The rapid discharge makes the cartridge and inflator extremely cold. Peaty’s says that direct contact can freeze its sealant temporarily, while its water-based Holeshot Biofibre formula recovers as it thaws.
That does not prove every sealant behaves in the same way. Stan’s warns that prolonged CO₂ exposure can separate its sealant or shorten its life. The practical lesson is to use the guidance for the product you bought, rather than borrowing instructions from a different bottle.
What the sealant brands actually say
Peaty’s Holeshot Biofibre: the manufacturer’s product guidance explicitly lists CO₂ compatibility. It explains that freezing from the cold discharge is temporary for this formulation, while declining to make the same promise for other brands.
Stan’s: its sealant support page recommends CO₂ for emergencies. After the ride, or after using it to set up a tyre, Stan’s says to release the CO₂ and refill with air. It links that advice to possible separation and a reduced sealant lifespan.
Muc-Off MTB Tubeless Sealant: the MTB product page lists CO₂ compatibility. Match that wording to the actual product you own; do not assume a claim on one sealant page covers every formula a brand has sold.
Using CO₂ after a puncture on the trail
First find the problem. Let sealant reach a small tread puncture, or use a suitable tubeless repair tool if the damage is within the repair system’s limits. A cartridge will not turn a torn sidewall or damaged bead into a sound tyre. If the tyre cannot hold a safe riding pressure, stop and use an appropriate repair or recovery option.
Check the inflator’s valve and cartridge compatibility before connecting it. Follow its instructions for piercing, opening and removing the cartridge, and use the supplied insulating sleeve or grip. Keep bare skin away from freezing metal and escaping gas. A controlled-release head makes it easier to add gas in stages than a system that discharges everything at once.
After inflation, inspect the bead seating and check pressure with a suitable gauge. Stay within the tyre and rim limits, using whichever is lower. Do not assume an entire cartridge produces the right trail pressure: tyre volume, cartridge size and the gas already in the tyre all affect the result. Our eMTB tyre-pressure guide explains the setup choices.
What to do when you get home
Follow the sealant maker’s aftercare. For Stan’s, that means exchanging the CO₂ for air as instructed. Let gas out in a controlled way without disturbing the bead unnecessarily, then reinflate and check that the repair holds. Inspect the tyre properly before the next ride rather than treating a successful journey home as proof that the damage has disappeared.
If the sealant has separated, dried out or stopped working, deal with that before riding again. Topping up blindly can hide a problem without fixing it. Our tubeless sealant guide helps compare options, but the bottle’s instructions remain the starting point for dose and compatibility.
Is a mini pump a better choice?
A mini pump is slower, but it provides repeated attempts without consuming a cartridge. That is valuable when you are still locating a leak or helping another rider. A rechargeable pump can offer similar convenience, subject to battery capacity; neither changes the need to make the tyre airtight first.
For long rides, carrying a pump alongside CO₂ gives you more options. The electric pump guide covers battery-powered alternatives, while a conventional pump avoids adding another charging job.
Does an eMTB need different CO₂ advice?
The motor does not change a sealant’s chemistry. The relevant differences are the tyre’s volume, casing, required pressure and the loads it carries. Choose an inflation setup that suits your actual tyres and keep the sealant maker’s guidance with your repair routine.
Can CO₂ seat a tubeless tyre?
It can sometimes provide the initial rush of gas, but success is not guaranteed. At home, a suitable floor pump, air chamber or compressor is a more repeatable approach than spending cartridges on a stubborn fit. Never exceed the wheel or tyre limit to force a bead into place.