Tubeless has been around for a long time on the MTB, and is gaining momentum on the road bike as well. More and more riders are taking the plunge. Earlier we wrote an article about mounting and the pros and cons of tubeless tires. Especially with modern rims, mounting is really not a big deal, maybe even easier than a regular tire system. But if you use older rims, it can be a challenge. And what can you do if you get a flat? In this article 5 problems and the solutions.

Photo: the new Continental GP5000 tubeless tires that CycloWorld is currently testing (photo by Frank Jansen)

1.The tire won't plop on initial fitment

This is probably the most common problem with tubeless tires. Here are some solutions, with the most obvious ones at the top.

• Remove the valve core when inflating. That way much more air can pass through the valve, which increases the chances of popping.
• Give the tire a blast of air all at once. You do this with a compressor, a tire booster or a CO2 derailleur hangerroon. If you opt for a CO2 derailleur hangerroon, make sure that you do not immediately add sealant when popping. This is because many sealants cannot withstand CO2.
• Spray the rim of the tire/wheel with soapy water. This is not a bad idea anyway, as it also makes the tire center better.
• Place a lashing strap over the tire tread and pull tight. That way the heels (called the bead) will be pushed up.
• An extra layer of rim tape will also sometimes help.
• Mount an inner tube, pump hard and leave for an hour. The next day, remove the tube through one side, install the tubeless valve and try to pop.

2. The tire does plop, yet air escapes along the edges

You see this problem much more often on older rims as well. It is usually caused by the rim of the tire not lying neatly in the rim everywhere. So the tire is not properly centered. Deflate the tire, spray the tire and rim edge with a soap solution or a special product such as Schwalbe Easyfit. Now inflate the tire and it will center itself.

There may also be another cause. In fact, there are two types of tubeless tires: tubeless and tubeless ready. The latter category needs sealant to stay pressurized; the cheeks are porous. If you don't add it, the tire may lose pressure. This is perfectly normal

3. The tubeless tire doesn't want to go on the rim

We are repeating ourselves, but this too occurs mainly on older rim types. These rims, unlike more modern rims, do not have a deep groove in the center of the field bed. Using that slot, you can create space to put the tire on the opposite side around the rim. If you use old-fashioned rims, fortunately there are some tricks.

• You can spray the rim with a soap solution or tire grease.
• Place the tire in full sun so it warms up or stretches a bit. If the sun is not shining, you can also use the oven at up to 50 degrees (not hotter!).
• A simple option is to use a tire ripper. Since you are not using an inner tube, you don't have to worry about puncturing it.
• But the most convenient option is a Tiresdomestique. There is also a mobile version of this for on-the-go, created by VAR tools.

4. The valve core gets clogged

Over time, sealant gets into the valve core; this is normal. It is recommended that when changing tires, always clean the valve cores with a soap solution and blow through well with compressed air, for example. Furthermore, regular replacement is also a good idea. Loose cores can be purchased for nearly nothing on Aliexpress. Of course, prevention is still better than cure. Especially after mounting, make sure that when you put your wheels away that the valve is on the 4 o'clock or 8 o'clock position. Then your valve is above your sealant and sealant in your valve can possibly leak out quietly by gravity.

5. My tubeless tire is still fine, but contains a hole too big for sealant

In that case, you have two options. The first option is to insert a plug from the outside. For example Dynaplug and Lezyne offer solutions for this. In fact, this is mainly intended as a homecoming solution, although some people drive on effortlessly. We know this solution from car tires ("shoot a prop").

Another option, perhaps a bit neater, is to stick a special tubeless tire patch from the inside. Hutchinson, TipTop and Velox make special kits for this. Some cyclists use an "ordinary" patch kit meant for inner tubes. However, this is not something you do quickly on the side of the road. It's better to just stick an inner tube and put a banknote in front of the hole, for example.