As you can see it's pretty obviously inspired by Allert but is drawn to fit over a 500cc Enfield that will be fitted with a 10hp aircooled diesel .These diesel Enfields get around 1.8 l/100km at 45 to 50 mph cruising .130mpg US without any fairing or aero mods at all .
As drawn the rear would slide out on heavy draw slides around 24 inches /600mm,adequate to throw a leg over .There would be storage against the rear of the frame and also in the sliding section .The fairing would be fibreglass just possibly with a bit of extra weight added low done to damp cross wind buffet .
The frontal area is around 7.5 squ ft .,the diesel has a theoretical efficiency of .3 and I have no idea at all of the cD.
.5 ?
Please excuse the basic hand drawing ,I'm not good with CAD.
http://pic40.picturetrail.com/VOL282.../398090017.jpg
THIS HAS BEEN MODIFIED TO INCLUDE MORE SPACING AROUND SCREEN AND ADDED AREA AT THE REAR .