neptronix said:I'm not an expert but i've been studying what experts have to say for months now and think i have a hang of it.
The rim shape makes complete sense since the tire looks like it would complete the shape.
This guy's fairing starts at beyond his width and creates additional frontal area near his shoulders and other areas.
The bottom part is a disaster. This was not properly measured before creation.
Despite these design disadvantages the fairing works well enough to increase speed, but was too impractically shaped.
So a badly designed but well built tail box does work.
..just like a kamm tail works on a car.
Well, if you think you can do better - go for it. Since your position is very un-aero to beging with, and unless you simply add a triangular tailbox with side converging at 45 deg (hope not!), it will work of course... just don't expect more than a few percent at right combination of speed and wind.
Kamm tail 'works' exactly because it is a 'lesser evil' - it allows to maintain a reasonable fairing length given proper convergence angle. Streamliners can get away with much 'stubbier' tail with steeper convergeance - because they are designed for certain patterns of air flow, guaranteed to be 'just turbulent enough' not to delaminate, but not TOO turbulent to prevent pressure recovery.
'Interrupted body aerodynamics', dealing with detached and reattached flows is a herculean task that stumps supercomputers, unfortunately... you'll have to experiement.