Tubeless conversion: the whole truth!

Let's debunk a myth: tubeless is not for all cyclists.

Those who ride occasionally (less than once a week), do not cross lands infested with thorns or - simply - do not want to face the small problems and complications that tubeless involves, can continue using inner tubes and be happy like that.

In off-road riding, however, the transition to tubeless and the use of tyre sealants has certainly improved the quality of the experience. For us "converted" to tubeless, greater traction, resistance to punctures and lower weight are advantages that can not be renounced.

Like all users of this system know, new problems are associated with the tubeless strengths. We then analyze step by step the tubeless wheel transformation, to see how to avoid and prevent possible problems in use.


Evaluation of materials: tubeless-ready is better

We strongly recommend using wheels and tyres explicitly designed for tubeless use. Currently the spread of "tubeless-ready" rims and tyres is such that you can enjoy the greater ease of use without a significant cost increase over "tube-type" tyres and rims.

Rim sealing

An unmissable requirement for the use of the tubeless tyre is an airtight rim. If the rim has (spoke) holes, it is necessary to seal them with the appropriate adhesive tape or with a tubeless rimstrip. We quickly analyze these two products.

Tubeless adhesive tape is usually lighter, but requires a (minimal) manuality for positioning, following a thorough cleaning of the rim channel.

Tubeless rimstrip, especially the latest generation like Effetto Mariposa Strip, has a great ease of use (no special cleaning, careful gluing, avoids problems in the case of rim channels with particular geometries, it can be removed and re-mounted if necessary) carrying just a little weight penalty.

Some tubeless-ready wheels are supplied "pre-taped". Also in this case it is important to assess whether the work has been done properly. If the adhesive tape tends to come off or covers the spoke holes in an approximate way, it is better to remove it and repeat the taping.

There are rims with a sealed channel (no pass-through spoke holes) that don't require taping.

Assembly of the tubeless valve

Sealed the spoke holes, let's focus on the valve hole. It is useless and counterproductive to seal the valve from the outside of the rim and allow the sealing liquid to enter the inner wall of the rim: the valve must be sealed on the inner wall of the rim.

This is possible only if:

  1. the hole in the tubeless tape is small and regular (better avoiding coarse "X" cuts);
  2. the geometry of the rubber base of the valve is adequate to the shape of the rim (therefore, flat or conical);
  3. the valve is inserted correctly and fully.

The tightening of the valve ring nut on the outside of the rim must be carried out strictly by hand. Using pliers not only does not solve any problems of air leakage at the valve (often it gets to deform the rubber base of the tubeless valve, permanently compromising the seal) but will make it impossible to disassemble the valve on the trail, in case of need .

Tyre and dry test assembly

The mounting of the tyre can be more or less easy depending on the make and model and the dimensional tolerances that exist for both rims and tyres. In general, it is better to operate by hand or with plastic levers.

The first inflation test can be done without sealant. This is to discover any problems of air leakage without wasting precious liquid.

Here are some precautions that allow you to inflate 99% of the tyres:

  • moisten the tyre talons with soapy water. This allows easier assembly and easier positioning of the talons. WARNING: avoid dish soap (it contains aggressive chemicals that could damage rim or tyre) in favour of neutral hand soap;
  • correctly position the tyre beads on the sides of the valve. It seems like a beginner's mistake ... but it can happen;
  • to maximize the air flow, remove the valve mechanism and directly approach the pump (or compressor) terminal on the valve stem. Once the tyre is inflated and positioned, it is not difficult to remount the mechanism on the valve without major pressure loss, with a minimum of manual skills.

If the dry inflation test is successful and there are no clamorous air leaks, you can move on.

Inserting the sealant

Once the tyre has been completely deflated, the sealant can be added. Personal insertion preferences range from using a dosing syringe to pouring the liquid directly into the tyre, after having partially disassembled it on one side. There is no right or wrong method.

What is important to note, however, is that the quantity of sealant used heavily affects the duration and effectiveness of the same, in case of puncture. The "usual" amount of sealant, which was used on 26x2.00 tyres, is insufficient now that we pedal on 29x2.20, to remain in the cross-country field. Better referring to the sealant manufacturer's site. Saving weight by inserting little sealant is a legitimate but not recommended practice.

Final inflation

Once the sealant has been inserted, repeat the procedure described for the dry test and take the tyre to pressure. What pressure? No need to exaggerate as in the early days of tubeless, when exceeding 3 bar was often needed to properly sit the tyre.

It is sufficient to reach a pressure that allows the correct positioning of the talons on the entire circumference. Excessive pressures can trigger air leaks that would not occur at normal pressures of use ... and if you go up even more a frightful blow and a sealant shower are in order. Better to avoid.

Tubeless stabilization

The sealant may take some time to permanently repair the small (or large) porosity of some tubeless-ready tyres. For this reason it is better to carry out a test ride with slightly higher pressure than usual, to allow the system to stabilize, or to insist by spinning the wheels for a while to favor a homogeneous distribution of the liquid. It is possible to see a marked loss of pressure in the first days after tubeless conversion, which tends to reduce as the sealant does its duty.

What to expect from the sealant

It should be noted that the two prevalent families of sealants, those "latex-like" and those "viscous with fibers" have different characteristics both during stabilization and use.

"Latex-like" sealants repair the holes by polymerization. Effetto Mariposa Caffélatex is a prominent member of the high performance "latex-like" sealants family.

These sealants have a low viscosity, which allows them to move quickly inside the tyre, thus reducing the amount of liquid needed for repair. Their life span is reduced by the fact of being intrinsically unstable and by making quick and "definitive" repairs of punctures.

"Viscous with fibers" sealants are of automotive origin and cyclically appear in the cycling world.

In this case the holes are repaired by obstruction, since the fibers they contain accumulate in correspondence with the damage. Not polymerizing, they have a very high durability, in some cases equivalent or higher than that of the tyre itself. The disadvantage is given by their viscosity, which necessitates the use of a quantity indicatively double compared to the "latex-like" sealants, and by the performances often inferior in case of porosity of reduced size, where the viscous liquid continues to ooze through the hole, unable to get (big) fibers into it.

A third way is represented by Végétalex sealant: although it contains fibers, it relies on Xanthan gum to close the porosities and allows to keep weight increase over "latex type" sealants down to about 20% more.

When using "latex-type" sealants, it is recommended to check the state of the liquid every two months, performing -if needed- a topping up to restore the ideal quantity.


  • Alberto De Gioannini

    C’est notre plaisir!

  • kit de conversion roues a rayons

    Marrant, j’aurais pensé que le tubeless se mariait mal avec le tout-terrain… Merci pour cet article!

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