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Drag reduction for upright bicycles
Consistent with aerodynamic improvements made to other vehicles I would like to see more done to reduce drag and energy consumption of common commuter bicycles. A typical bicycle has a frontal area of 4 sq. ft. and a drag coefficient of 0.6. A rider's body acts like a pump vane. A front fairing and tail box can offer weather protection, cargo capacity, and drag reduction.
I have been experimenting with simple fairings using cut and fold methods of 4 mm Coroplast. The wind load on a fairing attached to the head tube compresses the top of the fairing. The sight line needed to view the speedometer can be blocked. I am continuing to reinforce the front fairing with various forms of tubing. I do coast down tests on a hill where there is a 30 ft. drop in 0.1 mile. A full body fairing that resembles a sailplane fuselage with a Kamm tail can be designed using the HPV body shell software at recumbents.com. There is provision in the software to make a shell for uprights. The file can then be used in CFD software to evaluate the shape.
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