While its main function is to demo a new fuel-cell technology, SiGNa's electric bike can travel 60 miles on a single charge
, which is nearly twice as far as most electric bikes. According to Wired, its fuel cell is filled with a powdery chemical that -- upon adding water -- generates hydrogen gas, which produces electricity. The chemical reaction is safe for bikers, and the excess electricity is stored in batteries that provide an extra burst when you're pedaling through tough terrain. These units are also interchangeable, so you can pop in another fuel cell right after you've drained one. All that is much more convenient than stopping and waiting for a battery to charge. The potential to swap batteries could be very important if SiGNa can develop more powerful models of its fuel cell for use in larger vehicles. You can pre-order now, but the SiGNa bikes won't be available until next summer.