I am going to try and fix my 70* sub frame tank.
The leak was on one of the brass screw inserts that holds in the battery. I went ahead and used jb weld to cover up the interface where the edge of the insert contacts the tank. Then, I placed a small washer over the area-leaving the threaded hole open. Then I covered that up with more jb weld.
Before beginning I cleaned the area with hot soap and water and then dried it off. I then used a file to take off a bit of plastic to make sure I have a clean surface.
I figure the insert came loose because of the battery moving around on rough trail riding. So I'll use a different way to secure the battery.
So for now, I don't need a sub frame.