I figured up the design & some calculations for the new tail box. As a result there has been a change of plans. The new tail box is going to be similar to this one:
http://www.wisil.recumbents.com/wisi...udatailbox.htm
But because I have a Vision with space under the seat I will form the fairing to come to a point to force the air around the box.
Starting at 8" above ground level, this is to allow room for me to fill the tire with air, the sides of the box will be 45" tall. The total lenght will be 36". This is from where the chain stays meet the frame under the seat to behind the rear wheel.
When I am building it I will need to have the Camel Bak & the seat bag on the bike to take into account how much space they take up & how to form or fit the box around them. When all is said & done they will be "in" the box.
It should take only two 4' x 8' sheets of coroplast to build this.
The top or lid will be rounded & tapered down to the back point of the box. Kind of like a fast back style race car.