Here is a Motobecane 40T Frame. The stock frame is rigid and could be easily bent. I traced out the pieces by making cardboard templates and then transferred them to sheet metal. Then I cut the sheet metal out with a cut off wheel. The sheet metal was then clamped in place. I borrowed one of my friends MIG welders for this project and it was kind of hard to adjust properly for the size of sheetmetal (cheap welder). I tacked everything in place and then burned it all together. The welds need to be reground, primed and painted from here, but the swingarm should be much stronger now.
MadMatMax 