Everything you never knew you needed to know about tyre sealants and e-bike punctures

Everything you never knew you needed to know about tyre sealants and e-bike punctures

With tyre sealants you'd think that pretty much everything you needed to know was in the name. However, if you think you've discovered a magical potion that offers prevention against e-bike punctures, you're going to be disappointed. That's not to say tyre sealants aren't a great product, just that spending a few minutes understanding how they work will help you decide whether - or what - backup you need rather than relying totally on your tyre sealant.

How bike tyre sealants work

A common misconception is that bicycle tyre sealants work by solidifying on contact with the air. Let's think about this for a moment. Unless you add your sealant in a vacuum then it's going to have contact with the air as it passes from the bottle to inside your inner tube or tubeless tyre. Sealants contain tiny latex or rubber crystals. When a hole appears in your tube or tyre the air begins to rush out. Imagine a room packed full of people with only one small exit. If the fire alarm sounds and all the people try to rush out through the exit at the same time you get a blockage. This is what happens with the latex crystals. Some sealant will spray out through your puncture but, assuming you have enough sealant in your tube or tyre, the number of crystal exceeds the available space and a blockage is formed. The puncture is plugged.

These plugged holes can last for the life of the tyre (or equally fall out because they are too small to be firmly wedged in the hole). The plug will dry out since the liquid part that the crystals were suspended in has either sprayed out of the tyre or tube or remains inside it.

Different manufacturers will specify different maximum hole sizes that their sealant can plug. No sealant can be guaranteed to plug every puncture. If you cut your tyre or tube on a piece of glass (a slash) then sealant isn't going to help.

Tyre sealants can be used inside regular inner tubes or with tubeless tyres that don't use an inner tube. You can even buy inner tubes that contain a sealant. However, as we've just discussed, adding a sealant doesn't offer total protection against punctures on your e-bike. The type of riding you do and where you ride will all influence the best puncture prevention solution for you. Let's look at the alternatives.

Tyre sealants with tubeless tyres

If you ride a mountain bike or e-mountain bike then you're probably familiar with tubeless tyres. Tyre inserts like Tannus Tubeless Armour are designed to be used with tubeless wheels and tyres with a tyre sealant. The sealant works the same way as if you didn't have an insert. The benefit of the Tubeless Armour is that is allows you to run lower tyre pressures for superior grip off-road. Unlike running low pressures without Armour, it also provides impact protection for your rims and sidewall support to your tyre. This sidewall support eliminates the squirmy feeling you can get if your tyre pressure is too low, and also helps keep the tyre sealed against the rim. Without an insert, your tyre can move away from the rim of wheel during cornering and both air and sealant escape (burping). For punctures in the tread or sidewall, Tubeless Armour has holes strategically placed within it to allow the sealant to flow freely and plug those holes. Again, the caveat that no sealant can guarantee to seal all punctures applies. However, with Tannus Tubeless Armour you can still ride home (slowly) on a totally flat tyre. So if you like to travel light, and the thought of carrying a spare inner tube for your wheels that don't use inner tubes is a head spin, we've got you covered.

Tyre sealants with regular tyres

If you're not interested in pushing the envelope of grip and performance off-road then tubeless tyre systems are probably overkill for you. Regular inner tubes can be used with a sealant. However, a more effective puncture protection strategy is to prevent the holes appearing in the first place. Tannus Armour offers 15mm of puncture protection between the tread of your tyre, and 2mm of protection at the sidewalls. It prevents around 90% of punctures. Fixing punctures at the side of the road is never nice, but fixing punctures on an e-bike can push the patience of a yogi. Just like its tubeless sibling, Tannus Armour can be ridden totally flat to get you home if you do manage to get a puncture.

Tannus airless tyres

The only 100% guaranteed puncture prevention strategy for your e-bike is Tannus Airless tyres. Made from a proprietory polymer called Aither, Tannus Airless tyres offer the feel and performance of a regular tyre but are impossible to puncture. For riding on the road or mild off-road they are by far the most popular puncture prevention for e-bike owners.