It was six years ago that we first heard about Bridgestone's prototype AirFree Concept automobile tires, which utilized flexing thermoplastic resin "spokes" instead of compressed air. As it turns out, a just-announced bicycle version of those tires may end up beating the original to the market.
Developed via a partnership between Bridgestone Corporation and Bridgestone Cycle, the new tires are made mainly from the same recyclable resin as their larger, heavier-duty counterparts – their rubber outer tread can also be recycled.
Flats are an impossibility, and the tires will never need to be inflated. Additionally, the company suggests that because of those attributes, the tires could allow for greater flexibility in the design of bicycles. On the downside, however, it looks like there's no way of adjusting their hardness.
Bridgestone is currently assessing the feasibility of the tires, and states that a commercial version may be available by 2019. In the meantime, anti-air cyclists may wish to also check out the Energy Return Wheel.