Cyclists have been relying on butyl inner tubes for over 130 years. Everyone knows the black-grey rubber tubes, everyone has patched or replaced them after a puncture. This could soon be a thing of the past. With thermoplastic polyurethane (TPU), a new material is entering the world of bicycle tubes that promises many advantages over butyl bicycle tubes.
 

WHAT IS THERMOPLASTIC POLYURETHANE (TPU)?

The well-known tubes are being replaced by TPU tubes. Because TPU
- thermoplastic polyurethane - has many advantages over the black rubber tube. Please also read our TPU introductory text. But what is TPU anyway? Thermoplastics are plastics that deform when heated and solidify when they cool down. TPU has long been used in manufacturing for the automotive, transport, aerospace, sports equipment and medical device industries.

TPU combines the high durability of plastic parts with the elasticity of rubber, making it the ideal material for applications that require repeated bending or compression of parts. Due to its elasticity, TPU is often used as an impact modifier in products such as helmets, protective packaging, vibration damping products and seals. TPU also has excellent abrasion resistance and is therefore used in applications with high friction (e.g. interior components of vehicles) or for electrical cables and insulation.

ARE TPU INNER TUBES BETTER THAN CLASSIC BUTYL BICYCLE INNER TUBES?

Yes, TPU bicycle inner tubes such as those from AERON can be created or engineered, so to speak. This means that engineers can give a bicycle inner tube exactly the attributes that the rider needs for the application in question. Of course, a TPU inner tube can be produced in different sizes and widths and also with a desired valve. But there's more: a TPU inner tube can be produced in such a way that it offers more or less puncture protection, it can be heavier or lighter and, of course, come in different colours. Many tests carried out by independent institutes and test magazines ultimately clearly show the advantages of bicycle inner tubes made of TPU over those made of butyl. They are:

Everyone knows bicycle inner tubes, whether they are road cyclists, mountain bikers, gravel riders or commuters. Everyone has seen and probably touched one of these black butyl tubes, at the latest after the first puncture. In fact, the cycling world is facing a kind of turning point, the good old black butyl tube could - and probably should - soon be a thing of the past.

The well-known tubes are being replaced by TPU tubes. TPU - thermoplastic polyurethane - has many advantages over the black rubber hose. But what is TPU anyway? Thermoplastics are plastics that deform when heated and solidify when they cool down. This property makes them ideal for the production of bicycle inner tubes, as they can easily adapt to different tyre sizes. TPU inner tubes can also be customised. For example, they can be produced in multiple layers, equipped with more or less puncture protection and produced in any colour.

Who can ride a TPU inner tube?

TPU inner tubes are suitable for all cyclists and can be used in MTB bikes, road bikes, everyday bikes, gravel bikes and even e-bikes. The type of use is also variable. Whether racing, touring or everyday use - TPU tubes have many advantages everywhere and in combination with all kinds of tyres, according to unanimous reviews from test laboratories, professional athletes and other users.

Let's take a look at the advantages of TPU tubes. Firstly the weight:

TPU tubes are significantly lighter than butyl tubes. While a road bike tyre made of the well-known material weighs around 120 grams, a TPU inner tube of comparable width weighs between 25 and 40 grams (including valve). Incidentally, the TPU tube also performs better in comparison with a tubeless system in which between 30 and 60 millimetres/gram of sealant plus valve are used.

TPU inner tubes require less air pressure than butyl tyres.

Due to the high surface tension and strength of the material, the tyre develops good stability even at low air pressure. It is therefore already well formed at less than one bar, when a butyl tyre is still flabby. With the TPU tube, lower pressures can also be used in the tyre casing, which significantly increases comfort when riding.

Puncture resistance - TPU is far ahead of butyl here too

TPU is more resistant to tears and cuts compared to conventional rubber inner tubes. If you want to puncture a TPU tube with a needle, for example, you need three to four times as much force to punch a hole in the material compared to a butyl tube. Even when it comes to the risk of so-called snakebite - when the tube is subjected to high pressure, it punctures the rim of the rim and creates two holes - the TPU tube impresses with its greater inherent stability and performs significantly better than a butyl tube. In fact, manufacturers can even produce their TPU inner tubes in multiple layers and thus improve the resistance of their products enormously. If a TPU inner tube does have to accept a hole, it can be repaired easily, cleanly and quickly with self-adhesive patches - no more roughening the surface as with butyl tubes, no more glue on your fingers.

Installation - how it works

Fitting the new TPU inner tubes is just as easy as with butyl inner tubes. Lift off the tyre cover on one side, insert the inner tube, pump it up slightly, lift the cover over the rim, inflate the tyre, done. The ease of fitting is the big advantage of the TPU inner tube over tubeless systems. Many cyclists shy away from the complicated tubeless installation - and rightly so. You have to be reasonably experienced to convert your wheels to tubeless, and at the latest after a puncture that the system cannot seal with sealing milk, you are faced with quite a mess.

Also perfect as a spare tyre

Even if there are die-hard tubeless fans out there, a puncture in open terrain is a problem, and if you can't close the hole even with a tyre plug kit, you'll need a spare tube. A TPU inner tube is also much better than a butyl tube for this purpose, as it is not only lighter than the rubber product, but also packs down much smaller. This is an advantage for all cyclists, but especially for bikepackers who have to carry a lot of luggage on their bikes on long tours anyway.

Less air loss

TPU tubes have a lower permeability compared to some rubber tubes. This means that they are less susceptible to air loss, which has a positive effect on tyre pressure and riding characteristics. They are also more resistant to weather conditions such as extreme heat or cold.

Sustainability and energy consumption

Both butyl and TPU inner tubes can be recycled. However, TPU products leave a significantly lower CO2 footprint during manufacturing. This is due to the raw material and the lower weight. Less water is also used in the production of TPU hoses.

Which hose is the right one for which application?

As already mentioned, an Aeron inner tube can really be customised. With this in mind, Aeron offers tyres for MTB, gravel, road, city and touring. These are not only available in different widths and wheel sizes, they also come in different categories, from super light models optimised for rolling resistance to very robust tubes that can take on anything, even off-road. Of course, there are also different valves with different valve lengths.

TPU inner tubes - the future of cycling

To summarise, it can be said that TPU tubes are clearly superior to the old butyl products in every respect. Summarised here once again:

The advantages of TPU inner tubes over butyl

• Lighter
• Work with less pressure
• More puncture resistant
• Better rolling resistance
• Easier to fit
• Smaller pack size
• Less air loss
• Heat-resistant even with rim brakes
• More sustainable