Purpose’s of Tail Frames/Tail Box is for assisting the displaced air mass back to itself reducing power robbing turbulence.
If possible, the tail box should be positioned close to the rear/outside portion of the riders shoulders for best results.
Many riders do not prefer the inconvenience of getting into a Body Socked bike – so - the tail box only concept is a great option.
The same Aero Wing tail frame is used for Semi Streamlining this Gold Rush. A stretchy fabric “Lycra/Spandex” is used to cover the rider for aerodynamic streamlining. The tail frame simply finishes what the front fairing started. The shape and size of the Tail frame/box is important so to minimize turbulent drag.
Note: – Keep in mind anytime cloth is used for streamlining, it is used for compromises of comfort and convenience. Smooth composite surfaces are known to be the fastest.