With this post, I do not intend to convince anyone of anything, but I do want to show why the tubeless system is a practically foolproof puncture-proof solution. If you are hesitating between installing wheels with tubes or with a tubeless system on your mountain bike, here are a few reasons why it is worth choosing the latter.
First of all, it is important to note that tubeless wheels require minimal but necessary maintenance. Although this maintenance is quite inexpensive, we should not forget it, since the sealant inside these wheels has a limited useful life and must be renewed periodically. One of the most recognized manufacturers, Joe's no Flats, recommends replacing the anti-puncture sealant at least every three months. This is because tubeless tires breathe through micro-pores, causing the liquid to dry out over time.
Tubeless sealant is usually made up of a mixture of ammonia, water, and some chemical adhesive such as latex. Although each brand has its own formula, these are the common ingredients. It is also possible to make the sealant at home—as many videos on the internet explain—although after trying it myself, I can say that it is not much cheaper than buying a liter at specialized stores.
Although this system is especially popular among those who ride mountain bikes, more and more road cyclists are opting for tubeless, thanks to its advantages in comfort, performance, and puncture resistance. Without a doubt, an option to consider whether you ride on rough trails or cover long distances on asphalt.
How tubeless works
The basis of how this sealant works, which rests inside the tire (the tire must be Tubeless Ready, as well as the rim), is that at low pressures and with an air leak from a small puncture, the sealant moves to the hole, and, helped by its adhesive compound and the pressure loss, seals that area quite securely. It is true that some pressure is lost, but it never drops below 1 bar, so we can finish the ride comfortably without having to get off the bike. If we have a pump or CO2, it won't be any problem at all.
What are "tubeless ready" tires and rims
To convert the wheels of our mountain bike to the tubeless system, both the rims and the tire need to be "tubeless ready." This means the manufacturer has prepared these components so that the inner tubes can be removed and a special tubeless valve can be used. These are valves with a removable core, and they can be purchased together with the sealant and the rim tape. This last element is very important, since the rim must be completely sealed off from the outside, with no air leaks. If the rim tape is damaged or we haven't installed the new one correctly, we'll find out when we add the sealant and inflate the wheel. If there are leaks, the sealant will be a dead giveaway (it's quite obvious).
Does tubeless sealant fix all punctures?
No, it doesn't. Unfortunately, it's not 100% reliable, so it's recommended to carry an inner tube in case the tubeless system doesn't do its job. When does this happen? Well, in cases of cuts in the tire. A hole larger than 3mm won't be sealed by the sealant, so plugs are usually used—a very effective puncture repair system, but not suitable if you encounter cuts or holes larger than those 3mm. In this dramatic case, you must resort to an inner tube. The Tubeless valve and the sealant must be removed, and the tube installed. There is a little trick for those cuts, although I have never been able to verify its reliability. It consists of putting small pieces of shoelace, about 5mm long, inside the tire, swimming in the sealant. Industry gurus say that in this case, cuts up to 3mm would be sealed, without the need for a plug, maybe even bigger ones. I insist, these are inventions and popular theories, only supported by a few personal experiences.
The big advantage of tubeless: weight reduction
While it's true that as a puncture protection system it's great, similar systems already existed, such as tubes with sealant inside. However, the fact that you can remove the tube from the equation saves about 150 grams of weight on your bike—a reduction that, if you tried to achieve on the handlebar, seatpost, or other components, would be very, very expensive.
Riding at low pressures
Another advantage is the possibility of being able to ride at low pressures without fear of the dreaded 'snake bite' puncture of the inner tube. Riding at low pressures, that is, 1.4 bar for example, is something very common nowadays. Wide tires, over 2.2”, give us a large volume, and with pressures between 1.4 and 1.5 bar we have better traction when climbing, and greater safety when descending and cornering, as well as more comfort in very rocky areas. We do need to take into account the weight of the bike-rider combination when choosing pressures, but certainly, with tubeless wheels, we can always go below 2 bar without any fear of punctures or unseating the tire. At this point, it is worth highlighting a relatively new product on the market: the Panzer. We are talking about a kind of foam 'pool noodle' that is placed inside the tire, and which not only prevents the tire from unseating, but also protects the rim in case of a sudden loss of pressure due to a major puncture. These systems have one big disadvantage: they absorb the tubeless sealant. If in a normal tubeless setup we have to replace the 60-70 ml of sealant (we're talking about 29”) every three months, when using these Panzer-type protections we will need to replace the sealant in half the time.
How much does it cost to switch to tubeless wheels?
If your bike is not relatively modern (we’re talking from 2017 onwards), you can buy a tubeless kit for around €30, although you will also have to change the tires since tubeless ready tires are less porous and therefore suitable for this anti-puncture system.
Tubeless wheels on the road
This is a different story. We are talking about pressures of 6-7, even 8 bar, and therefore, too much force to be contained at the pressure leak point for the sealant. For pressures up to 5 bar it is more than proven that tubeless is a great anti-puncture system, especially against very small holes, caused by a small nail or tiny pieces of glass. In this case, we would be talking about 28 or 30mm tires. For 25 or even 23mm tires. In road cycling, tubeless is still in its infancy and still needs to evolve, since at 7-9 bar it is not effective. In conclusion, I highly recommend the use of tubeless wheels in mountain biking. But although I have been using it for several years and am more than satisfied, I never go out without an inner tube in my tool bottle just in case.