This I worked with early 2009 during the winter.
Got some good help with problems I had on advrider.
Had the rear spring out and had pulled the rear wheel up to see that I still could use the full suspension length and worked with cardboard to see what I could do:
Some bending and the welding I had help with from a local company producing aluminum trailers, main tank and top mount done:
Not a lot but it clears:
Had to cut a corner off and custom hammer a pieces and have welded shut so I didn’t have to cut the plastic:
Time to check for leaks …have a few so had to go get them welded back up:
Done, just fuel line left to hook it up:
Later had some trouble with fuel being pushed out through the air hole in the rear tank at highway speeds, that was solved with a one way valve.
First fill up:
And it holds 11,3 liters (very close to 3 US gallons) and since I aimed for above 10 liters I’m Happy!
Might not be the super good looking but I prefer function before fashion, and the added range is great, less worry about looking for gas stations!