No speeka Bark Busters, specifically . . . GENERALLY, however, adding mass (as in, hand guards) to an elastic structure (as in, handlebars), results in a longer vibrational PERIOD. That is, fewer vibrational oscillations per unit time. IT SHAKES SLOWER!
Now, as to amplitude . . . maybe, just maybe . . . should a "perfect storm" of additive conditions appear, a precise RESONANT FREQUENCY might be awakened by the addition of the specific Bark Busters' mass, and . . . the handlebars will try to shake themselves apart from the physical change!
Most unlikely, in my view, but . . . strange and destructive things have happened from RESONANCE (typical examples: certain suspension bridge, aerospace structure failures).
Only ONE WAY to find out whether Bark Busters convey this arcane phenomenon to Generation 1 KLR650 handlebars!
Otherwise, Tusk handguards do NOT, in my experience!