When was the last time you thought about the inner tubes in your bike? Last time you changed tires? Last time you flatted? Just an enclosed rubber tube with an air valve, this most humble of components is straightforward enough, but gets very little credit.
Not much has changed over the years with the bike tube. It comes sized to match different tire standards, with a Presta or Schrader valve and in different valve lengths. But the material choices—butyl or latex—have largely remained unchanged over the years. However, in the past few years we’ve started to see innovation in this area. A brand called Tubolito has been making a super-light, durable tube made of a thermoplastic elastomer. And now German tire brand Schwalbe is rethinking the tube with a thermoplastic polyurethane version called Aerothan.
Schwalbe has been pushing the adoption of tubeless tires for many years now, and especially road tubeless for the past several years, so it’s interesting to see the brand develop a new tube. But there are many riders who still prefer tubes, and as Schwalbe shows with Aerothan, there are many aspects of traditional tubes that can be improved.
One of the biggest selling points of the Aerothan tubes is low weight. Schwalbe claims the tubes are as light as 41 grams for a “Race” (700x23mm-28mm) version—our sample tubes weighed in 46 grams each. That’s about 40 percent lighter than a comparable traditional lightweight tube from Schwalbe. The tubes also have a smaller footprint to better fit in your flat kit.
Traditional tubes have a great range in variability in weight. One tube in our service course sized for 23mm-28mm tires with an 80mm valve weighed in at 121 grams, and another 18mm-25mm tube with a 60mm valve weighed about half that at 63 grams. But either way, the Aerothan tube is lighter, and offers a simple, relatively cost effective way ($31.99) to shed weight. Depending on what tubes you are running currently, there are potentially over 100 grams to be shaved from your bike with Aerothan tubes.
There is also a “Race/Endurance” (700x28mm-35mm) version that weighs a claimed 50 grams, an “Allround” (700x37mm-50mm) version that weighs 61 grams as well as mountain bike versions for multiple tire sizes in the 26”, 27.5” and 29” standards. Each version comes with a 40mm valve, which is compatible with standard valve extenders. Each version costs $31.99.
Schwalbe spent five years developing this new clear thermoplastic polyurethane material, chasing both low weight and durability. In the hands, the material feels more robust than standard tubes, like holding a plastic tube (which is what it is). Schwalbe’s testing confirms this robust feel. The brand says it takes a force of 47 newtons to puncture the Aerothan material, about twice compared to other standard tube materials. Schwalbe also says this material holds up better against conditions that cause pinch flats than other tube materials. We haven’t spent enough time riding these tubes yet to experience any real world difference in number of flats (though there are none to report so far), but just from installing them they feel well built and ready for a long life.
For those still running rim brakes, there’s an important additional durability feature: heat resistance. Aerothan tubes can withstand heats in excess of 150 degrees Celsius (302 F) so you don’t have to worry about overheating your tubes while descending.
Ease of Setup and Riding Benefits
It takes very little air pressure for Aerothan tubes to hold their shape, which makes installation easier, with less risk of the tube folding over itself or otherwise getting caught during installation—we had no issues setting up the “Race” version. And because they hold their shape at much lower pressures, they can be ridden at lower pressures than other tubes, as little as 1 bar (15 psi) for the mountain bike versions.
Aerothan tubes also have low rolling resistance similar to latex tubes and tubeless systems. We can’t say we particularly noticed on our test rides, but don’t discount the benefit of knowing you have every possible advantage.
And because these tubes hold their shape, they also do not lose air suddenly in the event of a flat, making them safer. And since they can be ridden at low pressures, you can continue to ride with a puncture until you reach a safe place to change your flat.
Is It for You?
Paying $31.99 for a part that we are conditioned to paying $7 to $10 for can seem like a hard sell. But for roadies seeking every weight saving advantage possible, it is hard to beat the dollar-to-gram-saved ratio for these tubes. And of course the numerous other benefits including durability make this worth a look.
And even if you run tubeless tires, you still need a backup tube or two—might as well have those backups be smaller, lighter and less likely to have degraded after living in your flat kit unused for a year.
More info: schwalbetires.com