I gotta say you have done some beautiful work. Your fab skills are obviously very good and what you have done so far looks beautiful. I have to say, though, your frame has a glaring weakness from the head stock to the lower engine cradle, and down the back bone. It looks like you have the potential for major lateral flex (almost a lateral hinge where the single tubes split into two at the rear of the engine and in front of the engine. The original XR frame uses a much larger cross sectional frame members there and they are much more reinforced. As originally intended it was they are adequate (in the dirt), but in this case, with a street (sporting) purpose, there would be much more lateral forces induced into the steering stem. The frame should triangulate from the stem to the rear of the main frame to try to keep the swing arm pivot and the steering head in line, and the upper shock mount should be in as direct a line as possible with the back bone.
This may never be an issue, if the intended purpose is a bar hopper, "art piece", or a cafe racer themed chopper. But considering the quality of the work you are putting forth, it just seems that purpose would be selling your self short.
Please don't take these comments as berating, or bashing. They are not intended to be as critical as they probably sound. I really do like what you are doing on this bike. They are just the musings of a mechanical engineer.
