an uncomfortable truth about air power

In my last post, I wrote about a mythical approach to transportation - one that relies on charged air. I still very much like this idea, but there are two big problems with it to be frank:

1) Pressured air (pneumatics) is much more dangerous than pressured liquid (hydraulics) – i.e. things can explode.
2) The control system for using compressed air as an energy storage medium is difficult to design.

The latter is going to be a big challenge for my air-powered bike idea. This is because as you pedal the bike and charge up your pressurized air tank that will be used to drive the wheel(s), the pedaling will constantly get harder and harder. One will require some gearing that will hopefully shift for you so that you can keep pedaling with a fairly even force imposed. Here’s a simple two-gear idea. It doesn’t require pedaling in the traditional sense, but rather an up and down motion like a stair-climber. The mechanism would require the shifting to simply lock one of the cylinders (while unlocking the other).