Could a piece of foam bring back mountain bike inner tubes?

Tubeless tires have become pretty much standard on higher-end mountain bikes, but they can be difficult to mount, and sometimes still end up leaking air. With that in mind, British bike tire manufacturer Tannus is introducing a product that is claimed to give tried-and-trusted tubed tires some of the same qualities as their tubeless counterparts.

Among the selling features of tubeless tires are the facts that they can be run at quite low air pressure (thus increasing traction), they weigh less than a tire/tube combo, and if they have liquid sealant added, puncture flats are less likely to occur.

Known as Tannus Armour, the new system offers a couple of those same features along with the easier installation of a tubed tire. It simply consists of a circular foam insert that goes inside a third-party clincher-style tire, sitting between the existing inner tube and the tire's inner wall.

On top, that insert is about 15 mm thick, providing considerable protection against punctures. The sides of the insert are around 2 mm thick, and they completely enclose the tube – this not only helps protect against sidewall punctures, but also minimizes the chances of getting pinch flats, in which the tube gets pinched against the rim on hard impacts.

Ordinarily, pinch flats are particularly likely to occur when riders don't keep the air pressure in their tubes high enough. Because of the protection offered by the Armour insert, however, Tannus claims that riders can safely go with tubeless-like lower pressures. In fact, if a flat does occur, users can still ride home at a speed of no more than 10 km/h (6 mph) using just the insert.

Tannus Armour will be available next Spring (Northern Hemisphere) in 27.5- and 29-inch mountain bike tire sizes, along with 700c sizes ranging from 35 to 40 mm. The insert weighs 270 g or 290 g for the first two sizes respectively, and 250 g for the 700c versions – although keep in mind that the weight of an inner tube also needs to be considered.

It will be priced starting at €29.99 per insert (about US$34). This puts it below the CushCore and Schwalbe Procore systems, the former of which is a flat-minimizing foam insert designed to bring a softer ride to tubeless tires, and the latter being a high-pressure inner tube that goes inside a tubeless tire, where it's surrounded by a very-low-pressure outer air chamber.

Source: Tannus via Pinkbike