[python] Elliptical chainring


Hello All, 
If you have thought  about mounting oval chainring on your python,  here is some feedback !
I did not put it on my steel Python, but on my TT/LD carbon bike, which I drive no hands. 
Thanks to Chainring Patterns from Giles Puckett
I've selected intuitively a 30%  eccentricity for my 56 teeth and 44 teeth chainrings to suit my 20" wheel 's 11-32 sprockets. to be used with 175mm cranks and automatic pedals. Height difference bottom bracket/ seat, +-90mm. Angle crank major  axis of ellipse, 0°.

Extremely pleased with the result. Only a few kms to get used to it. Getting an as smooth pedalling as with round chainring is no problem at all at low or high speeds. Feels more efficient when pushing from medium to hard, and uphill, and more comfortable too.

Specific bonus for moving bottom bracket recumbents, Pythons, Tom Traylors/ Laurent Dechenne :
When I push hard on the pedals, I suspect the effort required  by the oval chainring is more progressive, making the coordination of the muscles of the back easier. (http://en.openbike.org/wiki/Pedal/Steering_Interference). Before putting them on, I thought it would increase the pedal steering interference. Good surprise for me, not at all,  the output is an increase of the straightness of the rolling path, with no detrimental side effect. 

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