NERDPORN:
The Vibranator is a very efficient tuned mass damper tuned for the resonant frequencies of motorcycle handlebars.
The vibration induced involuntary muscle firing that causes numbness and tingling is the result the nervous system's defense mechanism that responds to a dominant consistent vibration frequency, the resonant frequency of the handlebar.
Tuned mass dampers interrupt and cancel the harmonic resonance so the vibration amplitude is radically reduced.
There are tuned mass dampers that use rubber as a spring. IMO, they are not as efficient as ones that use a metal spring. The rubber spring absorbs energy in both directions that should be used to exploit the oscillating mass better. The Vibranator uses hard rubber that is tightened/preloaded for mounting purposes. The mass is suspended by the metal spring and is allowed to move freely.
The end result is extreme hand pain relief and perception of a higher quality motorcycle. If your steering wheel buzzed in your car when it was new, your perception would be that it's not made well. That's why well built cars have many tuned mass dampers in them.
http://en.wikipedia.org/wiki/Tuned_mass_damperhttp://en.wikipedia.org/wiki/Tonic_vibration_reflex