Tubeless tyres are now standard across most cycling disciplines — from competitive MTB to fast road bikes. This technology offers better traction, lower rolling resistance, and the ability to ride at lower pressures. However, the key to fully exploiting these advantages is proper use of tubeless tyre sealant. This specialist product protects against punctures and maintains system integrity, but to work effectively, you need to know when and how to use it.
Mountain biking — off-road challenges
MTB is a discipline that places uncompromising demands on equipment. Rocks, sharp roots, glass fragments, or steel debris hidden in mud — all of these are potential puncture sources.
Tubeless tyre characteristics in MTB
In mountain biking, tubeless tyres allow riding at pressures 30–40% lower than with inner tube systems. Lower pressure means better grip on loose surfaces, greater comfort, and more precise control on technical sections. However, at such low pressures, the tyre is more susceptible to damage from sharp edges — resulting in so-called snake bites, where the rim pinches the tyre against an obstacle.
This is precisely where sealant saves the day. The liquid inside the tyre immediately fills the damage site and, reacting with air, creates a flexible plug that restores integrity.
How does sealant protect against damage?
Sealant works on multiple levels. Firstly, it seals the microporosity of the tyre itself and the rim tape — components that by nature aren't 100% airtight. Secondly, it responds to punctures up to approximately 6 mm in diameter (depending on the formula), plugging the hole from inside. The mechanism is simple: air pressure pushes liquid towards the leak, where it coagulates to form a durable seal.
In practice, this means that whilst riding over sharp rocks in the Alps or Tatras, minor punctures seal automatically without needing to stop for repairs. For off-road cyclists, this is a tremendous advantage — the ride continues without interruption, and puncture-related stress drops to almost zero.
Road cycling — performance and safety
Road cycling presents entirely different requirements. Here, every watt of power, every second, and every gram of saved resistance counts. Tubeless tyres have their role in this discipline too, but the priority shifts from extreme protection to maximising performance.
Minimising rolling resistance
Road tubeless tyres offer lower rolling resistance. Sealant supports this effect by eliminating friction between inner tube and tyre (which simply doesn't exist), whilst also allowing stable pressure to be maintained over extended periods.
In road tyres, sealant is lighter and more fluid than MTB variants — it doesn't contain such large sealing particles, meaning it doesn't excessively increase the wheel's rotational mass. Nevertheless, it still fulfils its primary function: sealing minor punctures that on tarmac most commonly result from glass shards, small tacks, or sharp stones.
Protection against minor punctures
In road cycling, punctures less frequently result from brutal impacts and more often from contact with small, sharp objects on the surface. Fragments of broken bottles, metal wires from car tyres, and even sharp thorns at the roadside — all of these can pierce a thin, delicate road tyre.
Sealant in a tubeless system responds to such damage immediately. The liquid fills the puncture before the cyclist notices any pressure loss. This means long-distance rides, randonnées, or group training sessions don't end with premature roadside repairs. This is particularly important during races, where every stop means losing position and group pace.
Other cycling disciplines
Tubeless tyres with sealant also work brilliantly in "hybrid" disciplines — combining road and MTB characteristics.
Gravel involves riding on hardpack roads, loose gravel, forest tracks, and sometimes tarmac. The terrain changes dynamically, so versatile protection is needed. Sealant provides peace of mind on gravel sections full of sharp stones, whilst not excessively burdening the wheel on fast tarmac stretches. Gravel bikes often use tyres 35–45 mm wide, providing ample space for sealant and increasing protection effectiveness.
Cyclocross involves off-road racing with numerous obstacles, muddy sections, and variable weather conditions. Tubeless tyres allow fast riding through mud without puncture risk from hidden sharp objects. Sealant is essential here, as there's no time for repairs during an intense race.
When to apply sealant
Proper sealant application begins at the tubeless system installation stage. This is a crucial moment — subsequent protection effectiveness depends on how carefully the first application is performed.
Installing a new setup
The best time to add sealant is during tyre installation on freshly prepared rims. Tyres must be tubeless-compatible (marked TLR or Tubeless Ready), and rims must be properly prepared — sealed with tubeless tape and fitted with tubeless valves.
The process is as follows: after mounting the tyre on the rim and initial inflation (so the tyre seats correctly on the rim), release the air, remove the valve core, and inject sealant through the valve opening using a syringe or special dosing bottle. Alternatively, you can remove one side of the tyre, pour sealant directly inside, then refit the tyre and inflate.
Preparing tyre and rim
Before sealant application, the inside of the tyre and rim must be clean. Residue from old sealant, dust, or dirt can interfere with the new liquid's performance. It's worth wiping the interior with a clean cloth or paper towel.
After adding sealant, the liquid must be distributed evenly inside the tyre. This can be done by rotating the wheel or lightly bouncing it on the ground. This ensures the fluid covers the entire inner surface, fills microporosities, and creates a uniform protective layer.
During the first day after application, it's worth checking pressure several times and topping up the tyre if necessary. New sealant works intensively, sealing the smallest gaps, which may cause slight pressure drop. This is normal and temporary.
Maintenance and refreshing sealant
Tubeless tyre sealant is a living product — it dries out over time and loses its properties. Therefore, it requires regular checking and refreshing.
How often should you check sealant condition? Every 2–3 months, regardless of whether a puncture has occurred. Factors such as temperature, humidity, and riding intensity affect drying rate. In high temperatures and low humidity, sealant evaporates faster.
During inspection, pay attention to:
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Liquid quantity — if no sloshing sound is heard when shaking the wheel, the sealant has probably dried out.
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Consistency — if the sealant has thickened or formed lumps, it needs replacing.
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Effectiveness — frequent pressure drops may indicate the sealant is no longer effectively filling microporosities.
Refreshing involves adding an appropriate amount of new sealant through the valve. For most MTB tyres, this is approximately 60–120 ml; for road tyres, 30–60 ml. Exact quantities depend on tyre width and manufacturer recommendations.
A full replacement is worth performing annually — remove the tyre, clean the interior of old, dried fluid residue, and apply fresh sealant. This ensures optimal protection and extends tubeless system lifespan.
Choosing the right sealant
Many sealants are available on the market, differing in composition, viscosity, and intended use. Key characteristics of a good sealant include:
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Sealing effectiveness — ability to quickly plug punctures of varying sizes.
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Longevity — resistance to drying out and retention of properties for many months.
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Compatibility — works with different tyre and rim types, no adverse reactions with materials.
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Ease of application — fluid consistency facilitating injection through the valve.
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Safety — free from ammonia and allergenic substances.
OC1 Tubeless Sealant meets all these criteria. The synthetic latex-based formula effectively seals punctures up to 6 mm, contains no ammonia, and is suitable for both high-pressure road tyres and low-pressure MTB, enduro, or gravel tyres. The manufacturer tested it in extreme MXGP conditions, confirming its durability and reliability.
Adhesion is also crucial — OC1 sealant adheres to the entire inner tyre surface, creating an even protective layer. This means it effectively seals not only punctures but also the microporosity of the tyre and tubeless tape, minimising natural air loss.
Summary
Tubeless tyre sealant is the foundation of an effective tubeless system — without it, the technology loses most of its advantages. Proper application during installation, regular maintenance every 2–3 months, and annual full replacement is a simple routine that ensures maximum protection. Whether the challenge lies on rocky MTB trails, fast roads, or loose gravel tracks, sealant provides confidence that the ride won't end with an unexpected repair stop.