Schwalbe EVO Inner Tube 2.1/2.50" Presta Valve 40mm

Schwalbe worked with BASF to develop what is by far, the lightest-weight full-sized inner-tube for mountain bike tires - and it is not made of rubber. The Evo tube is made from a thermoplastic called Aerothan and its Presta valve stem is molded from high-strength polycarbonate material. Evo tubes are not puncture proof, but are claimed to be the equal of a conventional inner-tubes in that respect. The use of alternative materials renders some unheard of weights: 68 grams for 26-inch, 72 grams for 27.5-inch, and 76 grams for 29-inch tires. And, we're not talking about wimpy 1.9-inch XC rubber. Evo tubes are designed to fit full-width enduro-sized tires.

Schwalbe's Evo tube could be a godsend for the handful of racers who have not yet converted to tubeless, because it comes in at half of what the lightest butyl tubes weigh, and when installed, it rolls almost as smoothly as a tubeless tire. 

Schwalbe's Evo tube is the ultimate back-up tube for anyone who rides tubeless tires. It is so lightweight and compact that for short rides I simply stash an Evo tube, along with a CO2 inflator and a mini tool, into the zip pocket of my TLD shorts. Two tubes can be tucked into the space normally reserved for an energy bar in a hydration pack. And, if you wear power panties, an Evo tube can free up a lot of precious pocket space in those cargo-bib shorts. 

• Weights: 68 grams for 26-inch, 72 grams for 27.5-inch, and 76 grams for 29-inch
• Presta Valve 40mm
• Size: 2.10/2.50"