[GP 125 & 250] Why hydroforming is not as good as welded cones?

Howard, thanks for all the great information, input and photos! I have hydroformed a number of pipes, some better than others. I just started rolling a radius on the edges before welding on my last attempt, but know that it tends to make my previously flat sheets into somewhat of a potato chip. Is that you are doing in the one photo, clamping the halves together so you can tack weld? Unfortunately my welding skills are only with a tig machine, with ER70 rod my joints seem to end up too hard to hammer smooth, will the mechanics wire help solve that issue, even tig welded? I make usually one off pipes for my vintage motocross projects, so hydroforming makes the most sense. First saw an article on the technique in a Performance Bike magazine 30+ years ago! I will have to figure out how to post photos, just joined this site.

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