Originally Posted by KCvale
Even with front shocks I can't see anything in the handlebars doing anything but off-setting the center of gravity higher.
Comfortable grips will do more than anything else for your hands.
Long distance motorcyclists often use bar end weights or shot inside the handlebar to change or damp the bar's resonant frequency, when that coincides with a common engine RPM. In the case of plain bar end weights, there isn't even any damping applied-- just changing the "note" the bar will ring into one that corresponds to an unused or less-used engine rpm range.
As you say, grips are more important overall. But when you have the unfortunate circumstance of 65mph in top gear on the highway being a frequency that gets your motorcycle's bars really buzzing, grips alone won't make it stop. That's the sort of situation where ballasting your bars can help a lot.
I think doing the same thing with the frame, which is orders of magnitude stiffer and therefore has a much, much higher resonant frequency-- is misguided at best.