Dual Chainsaw Starter Wheel

I've recently been tinkering with chainsaw starters as bicycle motors. If pull-cord type chainsaw starter motors were attached to both sides of a free-wheeling drive wheel hub, then both chain and pedals could be eliminated. This is mainly a design for recumbent bicycles.

However, for conventional diamond frame bicycles, if the cords were attached to the upper torso from the back then a bicycle could be operated abdominally. In this arrangement, the rider would be using arm and abdominal strength, to pull the cords alternating from aerodynamic position to upright riding position repeatedly.

While experimenting with this type of mechanism, I was thinking about the advantages of using this type of motor over pedals. In conventional bicycles, in most cases when cycling shoes are not worn, the upward motion of the cyclist's legs are wasted. Using cords and pulleys, one leg extension could result in more revolutions than pedals. Furthermore, the bicycle could operate in differential ranges of motion, from short powerful bursts, to long full extensions.