[python] The Python genisis

Jürgen, you mentioned that you were dissatisfied with the Airbike because of it seat height, speed and front wheel traction. I am interested in understanding more about the issue of speed. Is it your experience that lower bikes have less wind resistance than higher bikes, regardless of the relative frontal area.
In my experience, I would have expected that my Jetrike despite its low profile would have a reasonably large frontal area because of its high seat angle and rear wheels sticking out. Yet on the flat, in gusty head winds I pass stronger riders on mountain bikes by a significant margin. The only way I can explain it is that seated at 30cm above the ground there must less wind pushing against me than other diamond frame riders seated at say 70cm above the ground.
I also suspect that on a diamond frame most of the time you are simply pushing down against your own body weight. On a recumbent low racer, you are pushing against the seat, so you can muster greater pedal thrust.
In 15-20 knot winds I can still cruise at about 28-30kph these days, and the other cyclists despite trying to draft off my rear, simply can't keep up. Its rather entertaining :)
I have also recently found that a tire pressure of about 65psi seems to be optimal on my maxis hookworm tires. I tried higher, but the front wheel gets so springy that I loose efficiency due to some tire scrub. Much lower and the rolling resistance becomes more noticeable. 

-h

Jürgen Mages wrote:
Before the python, I rode an airbike (2x26" wheels, 50 cm seat height, center-steered). The seat height, speed and front wheel traction didn't satisfy me. Also I expected big advantages in the ability to reach the ground with both hands. I sketched the lowracer version of an airbike and found out, that a negative trail was inevitable. Without having an idea about the self centering effect I started the building to see if it might be rideable nonetheless. The suspension I copied from the ZOX bikes (which were invented by Sergio Gomez in the same workshop). I remember the first ride being very shaky and instable. I guess most people would have dumped this bike after the first riding trials. Stubborn as I am, I continued trying for weeks until I felt safe and began to love this bike. I built a second python together with a friend and then a third one which is still my primary bike. The first one is nowadays ridden by my wife. You know the rest of the story. 

Cheers,
Jürgen.


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