Most of us have moved on from using inner tubes in our tires and have embraced the benefits of tubeless but there's still a value in carrying a tube in your back pocket or under your seat for a worst-case scenario to nurse you home.
Whether in your tires or on your body, it makes sense to get the lightest tube possible so in recent years we've seen brands move past the traditional materials of latex and butyl to use thermoplastic polyurethanes for tubes that are claimed to be both lighter and stronger than ever before. Tubolito was the first to market with the technology and Schwalbe released its own version with the Aerothan in October last year
. Now it's Pirelli's turn with the Smartube, which has taken inspiration from the brand's World Tour tubular tire that was launched for the Giro D'Italia this week
Pirelli says its tubes are made from a thermoplastic polyurethane (TPU), and that they will save up to 70% of the weight of a general butyl tube while being stronger at the same time. The other advantage these tubes have over a standard rubber tube is that they are claimed to take up 50% less space, meaning you'll have more room in your pockets or bags for other gear.
Three mountain bike options are available - 29x1.8/2.2 (claimed weight 75 grams), 29x2.2/2.6 (claimed weight 100 grams) and 27.5x2.2/2.6 (claimed weight 95 grams). These numbers are slightly heavier than the claimed weights for both Tubolito and Aerothan tubes but they are lighter than comparable latex tubes and they should also have better air retention (latex tubes typically need to be re-inflated before each ride).
The tubes come in Racing Pirelli yellow, have a 60mm valve and don't come cheap at $36.90 per tube.