Originally Posted by Kontact

A friend makes custom railings. He torch bends mild steel tubing after packing them with dry sand to keep their roundness without using dies. I have no idea if such a technique is applicable to handlebar steel, and I suspect using such a technique would make it very difficult to make something symmetrical. However, if you are just taking an existing bar and modifying a portion of its existing curvature, it might be possible with trial and error.

I'll let someone else decide whether that is hacky or not, but he does it for a living. It is also used for custom exhausts.