Bar end weights - What do they do?
 

Probably a stupid question, but what purpose do they serve.

I can not see how that are actually heavy enough to provide any stability benefits and do not like they would protect much if you dropped the bike.

i think they are used to counteract vibrations from the engine being transmitted through the handlebars..

Yep nice heavy steel ones stop bar vibrations that can make your fingers numb. But they are also very good as crash protectors as well, not the crapola suzuki ones (the bolt is rubish). They save the fuel tank from touching ground in many cases.

Crash protection and vibration reduction. Even the standard ones are substantial enough to reduce vibrations and help save the bike. Heavier ones do even more.

Oh, and the bolt is crap, yes, but the reason for that is so that the bar end moves rather than bending the clip on.