"I never ride tubeless. Too much effort. And then there's the mess with the latex slop," were the words of my biker friend
biker friend before a short holiday in the Bavarian Forest. Two days, several punctures and an exhausted supply of spare tubes later, he had to give it a try. By the end of the holiday, he was a convinced tubeless rider. This is how many people feel when they overcome their fear of tubeless systems and experience the advantages on their own bike. As far as puncture statistics are concerned, the advantages are obvious. The annoying punctures (caused by thorns, for example) are usually sealed immediately and unnoticed by the rider. Punctures occur much less frequently due to the lack of a hose. What's more, you can also ride at low pressures with confidence. In favour of comfort and traction. In rolling resistance measurements, tubeless-ready systems occupy the top position together with latex tubes. Almost all new developments in tyres and rims are now tubeless or tubeless-ready.
As is so often the case, the success story also has a weak point here: the fact that the fit of tyres and rims is not yet standardised - something that has long been taken for granted in the automotive industry. However, thanks to the intensive cooperation between tyre and rim manufacturers in recent years, well-functioning combinations are no longer the exception, but rather the rule. The signs are therefore very promising, even if there are still exceptional combinations in 2014 that can spoil the fun due to fitting problems or difficult inflation. In the following workshop, the first in our tubeless series, we will show you how most wheels can be converted to tubeless and present a selection of the latest sealing milk products from various manufacturers.
Advantages of tubeless systems on mountain bikes
- Less susceptible to punctures
- Punctures are often sealed immediately and unnoticed
- Hardly any more punctures
- Lower rolling resistance
- Weight advantage
- Low tyre pressure, more comfort and traction
Disadvantages of tubeless systems on mountain bikes
- Complex fitting, especially with unfavourable tyre/rim combinations
- Milk must be topped up regularly
- High price compared to the inner tube
The rims
A distinction is made between three types of rims according to their tubeless properties: Rims not designed for tubeless use can be recognised by their evenly round rim base right up to the rim wall. They can only be safely converted with tricks (see below).
Tubeless-ready rims only become airtight with the help of a sealing tape. However, they already have a special cross profile that is optimised for tubeless.
"Genuine" tubeless rims have no spoke holes and are therefore inherently airtight. However, they are usually heavier and more expensive due to the special challenges involved in their manufacture. Each manufacturer determines exactly what the cross profile of tubeless-ready and tubeless rims looks like.
The accessories for retrofitting
When choosing a sealing tape, it is important that it is wide enough to cover the rim shoulder. You are also spoilt for choice when it comes to tubeless valves. Almost all of them are Presta valves. Little helper: This small tool helps you to remove the valve core if necessary and screw it back on securely.
Tip for converting old rims
In principle, almost any rim can be converted to tubeless - however, rims that are not designed for tubeless tyres can pose a considerable safety risk. These rims have no raised, flattened shoulders and no special rim flanks in which the tyre bead can engage. This means that there is a risk of air escaping suddenly at low pressures, steep inclines or hard landings.
For this reason, various manufacturers (Notubes, Zero Flats, Bontrager, Dt-Swiss and others) offer profiled sealing strips, often made of elastic rubber or harder plastics. They are not only intended to seal the rim, but above all to help fix the tyre more securely to the rim. Tip: Practical experience shows that it also makes sense to additionally prepare the rims with an airtight tape (as above).
This is how it works: The do-it-yourself conversion in 14 steps
TIP: Even after a successful conversion, be sure to take a short test ride before taking the bike off-road.
Sealant and puncture protection
Sealants and puncture protection agents ensure that tubeless-ready tyres are airtight. However, they also repair minor defects such as punctures and holes of a few millimetres on their own. The manufacturers are tight-lipped about the exact mode of action of the individual compounds. However, what is often referred to succinctly as "latex milk" due to its milky appearance is a real high-tech product.
Everything you need to know about sealing milk
How long does the sealant last in the tyre?
This depends heavily on the porosity of the tyres and the conditions of use and can vary between two and ten months. If the liquid dries out, any sealing function is lost. Therefore, check regularly by shaking to see if the milk in the tyre is still liquid.
What to do if the floor pump is not enough?
With good rim/tyre combinations, a floor pump should be sufficient. If not, a blast of compressed air from the compressor or a CO² cartridge (if approved) will help. But: always apply with the valve pointing upwards. Some sealing solutions react to the temperature shock of the compressed air.
Tip 1
Almost all solutions contain solids or particles, some of which physically seal the holes or act as catalysts for a sealing reaction. As these settle to the bottom, the solution must be shaken thoroughly beforehand to obtain a homogeneous mixture. This is the only way to guarantee the full function of the breakdown milk.
Tip 2
Chemical/physical reactions take place in the sealing solutions, which are accelerated by contact with air, light and heat. Without cool, dark storage in a tightly closed container, the sealant ages very quickly and becomes unusable.
What if a flat tyre does happen?
The first step is to get the milk to the damaged area. To do this, hold the impeller so that the milk can collect there. This is often enough. There are also special products, such as the GEAX Pit Stop Magnum (€10.90), which seal and inflate the tyre at the same time.
If that's not enough?
Then it is often easiest to insert a spare inner tube. However, it is essential to remove all thorns from the tyre beforehand, otherwise the next puncture is inevitable. Recently, special repair kits have also become available. The Genuine Innovations Repair Kit is a smart solution for small punctures. Larger holes or cuts must be repaired from the inside, for example with the Tubeless Rep'Air Kit (9 euros).
Can the sealing milk freeze?
Due to the addition of glycol (a typical anti-freeze agent in cars), almost all emulsions are approved for temperatures down to minus 15 degrees. However, the sealing reaction is slower at low temperatures.
Can the liquid damage my tyres or rims?
The sealants of the first generation sometimes attacked the tyres or bare rims due to the ammonia they contained. This risk hardly exists with the current solutions.
