I looked first at the volume of the space taken up by rotating the feet on 175 mm cranks, and compared that to 140 mm cranks. Being so far forward it makes a difference in the volume of the nose and it is easier to push through air.
Also with this I wanted the following:-
- A single simple form with no jointed surfaces, spats and head-farings. All joints on exterior surfaces of aircraft have fillets between them to reduce vortex drag.
- The simplest drive line.
- A faired recumbent bicycle that did not fall over when you try to get in or stop.
- I wanted it to tilt into a curve to reduce the loads and stress on the wheel system and chassis so they can be lightly built.
!75 mm compared to 140 mm crank frontal areas
140 mm crank rotational volume.
The chassis bounded volume with 26 inch front wheel and 20 inch rear wheels. The chassis will be built from 3.4 mm Corex and 11.5 mm honeycomb board hot-glue gunned with 12 mm conduit.