Frame question

[dingleberry]

Thought I should post a pic (rough concept by editing) of my 400. The tank is from a Wards Benelli. Would like to beat one out of alloy to this shape (who has an AC tig? :))  . Plan on remodelling the rear section of frame.
Why is the pressed steel part of frame behind rear cylinder not symetrical? Would it have something to do with torsional forces/strength or just a place to put battery? I would like to cut into it and weld down tubes on etc.
Any thoughts? :-\

[The Prophet of Doom]

Cool.  I presume that Benelli tank is photoshopped to larger than life and you can't just buy one? And if you could it would be shot anyway?  What are your beating skills like? 

If you look at one of treedragon's pics carefully you will notice his rather cool mod in that part of the frame.

[dingleberry]

Yeah its all not scaled very well, no photoshop just cut and paste from paint program.

That tank in the photo is in my shed in mint condition. I have the engine to match. Thats a whole different project.

My beating skills are non existant but I'll have a crack at it - it's something I've been keen to learn for a while now. Chap down the road has an english wheel/swager type of contraption so that will help. I'll try to shape it similar to Benelli tank. Don't expect rapid progress in this area.

[jefferson]

The frame has to clear the swingarm with the shaft and knuckle inside it. Look at how large the swingarm opening is to accommodate the knuckle on the left side.

Jeff