As petroleum becomes more expensive, worldwide more people will be using buses and trains to get around. A compact bicycle which can be carried easily on the bus, unfold quickly, and be comfortable to drive will enable people to reach the bus stops more rapidly. This vehicle has features one might expect in a car, and can be made smaller, lighter and cheaper than a bicycle.
This vehicle uses two flat pedals to drive pumps. The pumps store compressed air in a lightweight bottle. The air drives a slam valve compressed air motor which drives the rear wheel directly. The pedals move independently and are rigid at the bottom of travel allowing firm balance and control for a standing vehicle. With no seat the vehicle is low and smaller versions could fit in a backpack. As with all human powered vehicles, the range is infinite and there is no recharge or need for fuel.
The air motor produces more torque when running slowly and less when running faster. This eliminates the need for gears and can switch smoothly and automatically between hills and flat areas. The motor also responds to fingertip controls to go faster or slower. The user does not need to pump all the time as the unit can run some distance on stored compressed air, or the user can add energy with one foot while waiting at a light.
When braking, the motor uses the momentum of the vehicle to pump air back into the bottle. This is regenerative braking which is very rare in small vehicles and very useful when operating in the city. Many bicycle accidents are caused by the drivers unwillingness to part with his momentum, regenerative braking makes a quick stop more agreeable.
As the air motor operates, the exhaust comes out cold. The cold air can have condensate separated out and be piped to the riders sleeve. This will keep the rider cool. In some tests the condensate came out as frost. Air conditioning is a rare feature in pedal powered vehicles.
The current prototype does not yet have its handlebars mounted and features 10 inch tires. A city vehicle would have 6 inch pneumatic tires and could be made much smaller and lighter if optimized for hard surfaces. Composite materials can make the vehicle much lighter still.
All in all, the compressed air power plant provides many features of a modern hybrid car while eliminating some of the larger parts of a bicycle. Regenerative braking, continuously variable automatic transmission, energy storage, and air conditioning would normally only be found on a very expensive car. This power plant eliminates the need for a raised seat, large wheels, and a large wheelbase to accommodate a chain allowing for a much more compact replacement for a bicycle at a production cost which is no higher. This provides good value to a society which will be accommodating more people with less resources.