Tubeless bicycle tyres are similar to car tyres, whereby an open rubber tyre sits firmly in the wheel's rim with no inner tube. Tubeless tyres are filled with sealant, which stops air leaking under the tyre bead (edge) and through the spoke holes. It stays liquid until there is a hole, at which point it rushes to the hole, dries, and seals it so the tyre stays inflated and you don’t need to stop. The system avoids pinch punctures, too, which is great if you ride off-road.
Mavic wheels that are supplied with tyres as standard are all tubeless ready. Mavic call this system ‘UST’. If you purchase a Mavic UST wheelset, the owner’s pack contains the tools you require to maintain the tubeless system.
You can install an inner tube if you would prefer not to use the tubeless system.
Maintaining tubeless tyres
Tyres should be checked for pressure before every ride; tubeless and non-tubeless tyres do leak air over the course of a couple of weeks or so.
Top up your sealant every few months. Sealant can dry out if you don’t use your bike and some can leak out if you puncture.
How to top up sealant
- Rotate your wheel to move the valve to the 12 o’clock position.
- Release air from the tyre a little at a time so that the bead stays seated.
- Use a valve core remover tool (this is supplied in the owner’s kit with Mavic wheels).
- Rotate the wheel so the valve is at 5 o’clock, and use the syringe to add sealant. The sealant bottle will recommend the amount of to add.
- Replace the valve core and inflate the tyre.
After a puncture
If you ride over something sharp and your tyre is cut, keep riding. You may hear the sound of leaking air or see sealant spraying out. The rotation of your tyre helps to move sealant to the hole, clog and seal it, stopping air loss.
Your tyre may deflate but by a small amount. Later on your ride you might want to stop to top up the air pressure in order to get the best ride performance from your tyres. If several punctures occur on the ride or over consecutive days, top up the sealant levels after the ride to ensure you have enough.
Packing your bike for air travel
If you plan to fly with your bike, deflate your tyres a small amount but ensure the tyre beads stay seated on the rim. Inflate to the correct pressure on arrival. Take a small tube of sealant so you can top up your tyres if needed.
If you haven’t used your bike for over a year, you may find your tyres aren’t inflating as easily as they used to. This is usually caused by dried sealant clogging up the valve. Either replace the valve with a brand new one or take the valve apart and scrape out any dried sealant with a pin or similar.
If your tyre becomes badly cut on a ride or the bead becomes unseated from the rim and air seal cannot be maintained, you can use a standard inner tube to inflate your tyre and continue riding as normal. Fit the inner tube and use in the same way as you would with a clincher tyre.
Types of sealant
If you wish to top up your tyres with sealant, we strongly advise not to mix sealant brands. Tyres are not specific to sealant or valve types and if you wish to change sealant or it has dried up, wipe out the tyre and use the new brand. Latex sealant dries up faster than other types of sealant. The air mixing with the latex solution causes a chemical reaction causing the latex to coagulate inside the tyre. Water-based sealants rely on a thicker liquid to physically plug the hole. Water-based sealants last longer but don’t plug the hole as quickly.
You can inflate your tyres with CO2, though CO2 canisters can cause latex sealant to dry out quickly.