I have often wondered if humans would be faster sprinting like an animal. I also feel that bicycles are inherently inefficient particularly when it comes to sprinting. Watch cyclists sprinting and you will see them throwing the bike from side to side which must be wasting an awful lot of energy. This idea is for an alternative pedal mechanism in which the pedals are mounted on push-pull rods running at say a 45 degree angle along the rear half of the bike. Rather than pedalling in a circular motion you now push and pull on the pedals in a straight line. The pedals are detached from each other and, in a sprint, the rider can switch to pushing and pulling both pedals together giving a much greater amount of thrust. The bike remains stable and therefore all effort is expended on moving forward rather than wobbling from side to side.
-- The_Saint, Nov 12 2009

In a high speed sprint cyclists are shifting about 10lbs or less of bicycle side to side in order to get the best possible line for the thrust of their legs. The energy lost is fairly minimal.

A cyclist using clipless pedals can push and pull a standard pedal set perfectly well (except for a small section of the upper back portion of the arc).

Pushing both pedals together would give more thrust in pulses, not continuously.

Also look up prone bicycles. I think this has the position your rider would have to be in.

I think your major development here is a more complex transmission that will add weight and inefficiency in transforming linear motion to circular.

I'm not saying this can't work, but bicycles are already the most efficient transportation in existence in terms of power in to power out.
-- MechE, Nov 12 2009


Some 19th century bicycles had pushrod pedals, seems they were abandoned once rotary pedals were invented.
-- pocmloc, Nov 12 2009


For some reason the title caused me to envision a vehicle which randomly ejects a percentage of its occupants, only operates on freshly paved suburban streets, and sheds various parts each year.
-- StationPilot, Nov 12 2009



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