Streamlining a bicycle?

[RoadCyclist]

That setup looks like it would act as a sail rather than a nose cone. You say you tested it?

[Grant-53]

Yep. Coast down course is 30 Ft. drop in 0.1 mile. Top speed was 16 mph with and 17 mph with just the bar grips inboard. The narrow bar grips are good for plus 1 mph by themselves. I rode this for a year in all kinds of crosswinds and did get a boost once from a tailwind in a storm. I cut a piece of 4mm coroplast 24"x44" then made slits to overlap for the shape. The tail box is the critical part as it needs to fit tight to the rider's back. Due to hip inflammation I have to build a step through frame and the box needs to be shoulder high down to just below the knees. Aspect ration is 3:1. If you go to the photo album the early drawings are there.
The funky nose cone and waste basket rig was good for +3 mph and stable in cross winds. The nose cone is made from one inch hex wire mesh bonded between 5 mil tarp plastic. The home made aero bars work fine and I mounted them on a frame with more under steer and a solid stem. I try to use low cost materials that are readily available. The HPV shell software at recumbents.com can be used to do shapes that can then be modeled on CFD software. One simple enclosure for a TT bike yielded a simulated 40% reduction in drag. For ecomodders any vehicle can be configured to get a 50% drag reduction. My goal is to cruise all day year round without breaking a sweat at 25 mph.

[Grant-53]

The picture COcyclist posted is my bike. People are skeptical about streamlining upright bikes but it is not that hard if you do some homework.