How to repair a tubeless puncture step by step
A tubeless puncture doesn't always mean ending your ride. In a properly mounted tire, sealant can seal small punctures while you keep riding. But when the hole is larger, located in the sidewall, or the pressure drops too quickly, knowing how to repair a tubeless puncture with a plug can prevent a long walk and protect the rim.
The key is not to treat all punctures the same. A puncture in the tread of an MTB requires different solutions than a sidewall cut on a gravel bike or a heavy e-bike. Carrying the right kit and recognizing the limits of each repair is part of basic maintenance.
Before repairing: identify the type of puncture you have
Stop in a safe place and spin the wheel to find the point where sealant or air is escaping. If the wheel is still mounted, leave the valve approximately at the 6 o'clock position. This way, the sealant will collect at the bottom and won't be lost while you inspect the tire.
A small puncture caused by a thorn, wire, or fine stone usually seals itself. Remove the object if it is still stuck, spin the wheel to bring the puncture to the bottom, and wait a few seconds. If the air stops escaping, reinflate and check the pressure.
If the sealant bubbles without sealing the hole, or the tire loses pressure in less than a minute, you need a tubeless plug. If you see a long cut, a sidewall tear, or an opening that deforms the casing, the plug may only be a temporary solution. In that case, you will probably need a tube and, depending on the size of the cut, a tire patch or an emergency tire liner.
How to repair a tubeless puncture with plugs
A plug kit takes up very little space and should always be in your backpack, saddle bag, or fanny pack. It includes an insertion tool and adhesive rubber strips of different thicknesses. For enduro and e-MTB riders, it is advisable to choose a sturdy tool, as reinforced casing tires require more force to puncture.
1. Remove the object and locate the puncture
Carefully remove the thorn, nail, or glass fragment. If you cannot see the hole, listen for escaping air and look for wet sealant. Do not remove the tire for a conventional puncture: you will lose air, sealant, and time unnecessarily.
If there is mud or dust covering the area, clean it just enough to work. The plug must enter the hole, not between the tire knobs or into a superficial crack in the rubber.
2. Choose the right plug thickness
A thin plug works best for small tread punctures. For a visible hole or a puncture that does not seal after several attempts, use a thicker plug or two thin plugs together. Do not force an excessively large strip into a lightweight gravel tire: you could enlarge the puncture and compromise the casing.
Insert the plug through the eye of the insertion tool, leaving both ends at a similar length. Some tools use an open tip that releases the strip when removed; others require turning or pulling with more precision. Practice at home with an old tire if this is your first time using that system.
3. Insert the plug without puncturing the tire
Push the tool straight into the hole until approximately 1/4 to 1/2 inch of the plug is outside the tire. Do not push it all the way in: if it punctures the casing, it may become loose inside the tire and will not seal properly.
Remove the tool with a firm motion. The plug should remain trapped in the puncture, with two small ends visible. If it falls out when you remove the tool, repeat the process with a new strip and make sure you have inserted it deep enough.
Let the sealant work for a few seconds. Spin the wheel so the liquid reaches the repaired area and check that there are no bubbles. If it continues to lose air, add a second plug next to the first. It is preferable to use two well-placed plugs than to keep trying with one while the pressure continues to drop.
4. Inflate to a useful pressure, not the maximum
After sealing, inflate with a mini pump, CO2 cartridge, or inflator. To continue the ride, you do not necessarily need to return to the exact usual pressure. You need enough pressure so that the tire does not de-bead, the rim does not strike, and the bike remains controllable.
On an MTB, a pressure slightly higher than what you normally use helps protect the repair, especially on rocky trails. In gravel, avoid riding with too low pressure if you have a narrow tire or a heavy load. On an e-bike, the additional weight of the bike and the assistance increases the demand on the tire: check that the pressure is appropriate for the total weight, tire width, and terrain.
CO2 cartridges are fast, but they have a downside: some sealants lose effectiveness or dry out sooner after contact with CO2. They work well for emergencies; when you get home, it is advisable to deflate, check the sealant level, and reinflate with regular air.
When a plug is not enough
Plugs are very effective in the tread, but they do not fix everything. A sidewall cut is the most delicate case because the sidewall flexes on every rotation and supports less pressure than the center area. You should also be wary of a repair if the tire has exposed casing, a bulge, several close cuts, or air loss at the junction between the tire and the rim.
When the plug fails, remove one side of the tire and remove the tubeless valve before installing a tube. If the cut is large, place a tire patch, a specific liner, or a rigid emergency solution between the tube and the casing inside. This prevents the tube from protruding through the cut and bursting when inflated.
Do not mount a tube over a thorn or wire without removing it first. It seems obvious, but it is one of the most common mistakes under pressure. Also check the inside of the tire with your fingers, taking care not to cut yourself, and look for debris that could cause a second puncture.
Mistakes that shorten the life of the repair
Trimming the ends of the plug flush during the ride is not necessary. At first, they may stick out a little and wear down while riding. If one end is left very long, trim it when you get home, never in a hurry by the trail if you do not have a safe tool.
It is also not advisable to ignore a repair that seems sealed. At the end of the ride, check the pressure and see if there is sealant around the puncture. A plug that holds air during a gentle ride may fail on a fast descent, in the heat, or under the weight of an e-bike.
Finally, do not wait until you get a puncture to find out you do not have sealant. Check the level every few months, or sooner if you live in a hot and dry area. Sealant evaporates and forms an internal film over time. A tubeless tire with little liquid may mount well, but it will not have a real self-healing capacity.
Recommended tubeless kit for MTB, gravel, and e-bike
To go out with a margin, carry a plug tool with several strips, a mini pump or inflator, a CO2 cartridge as a backup, tire levers, a tube compatible with your wheel size, and a valve adapter if your pump requires it. On remote routes, add a tire patch and a spare tubeless valve.
The tube size must correspond to the diameter and a width range compatible with your tire. For example, a tube for 29 inches is not always suitable for a 29 x 2.6 if its range ends at 2.4. At Zbikes, filtering by diameter, width, and discipline greatly simplifies this purchase, especially if you alternate between an MTB, a gravel bike, and a city bike.
A well-done tubeless repair allows you to finish the ride, but it does not eliminate the need to check the tire afterward. Clean the area, confirm that the plug is still secure, and replace the tire if the cut threatens the casing. Getting home riding is the goal; going out again with confidence is the next.