bar end weights

On my new 961 SE, I have been a little surprised at the amount of vibration in the handlebars at cruise rpms (about 4500), given that the bike has a counter balance shaft. Yesterday I installed some new bar end mirrors and put some old Ducati bar end weights on, for cosmetic reasons. What a difference! Vibration at the hand grips is almost gone.
As I understand it, one of the advantages of 'fat bars', as installed on the new Nortons, is less vibration, something to do with the gradually tapering diameter. Perhaps they need a little weight at the end for that to take effect.
The bar end weights that came with my bike weigh just 29 g (1.0 oz) The Ducati Monster bar end weights I installed are 163 g (5.75 oz). Of course, the bar end mirrors I installed add some weight to the end of the bars as well.
On the freeway, the mirrors have less vibration than with the stock bar end weights, as you might expect.

Are the original bar end weights you are referring to the end caps? Mine does not have weights, but just caps. They could weigh 29g, including the allen bolt and fixing nut.

I ordered weights as i dropped the bike a few days ago, and one end cap is scuffed. When they arrive i will post results. But i have absolutely zero mirror vibration with my rizoma mirrors on a stock handlebar setup.

My dealer put bar end mirrors on instead of weights on their demo bike and there was no vibration at all that I noticed....

I've been using Oberon bar end mirrors on mine for a year or so and took them off (for safety) when my bike was couriered in a van back for service. I went to Donington myself to ride the bike back home and as they are easy to fit I took the original mirrors with me for the ride back. I'd almost forgotten the vibration you get around 4-5k revs! Oberon's are made of steel and weigh a fair bit more than the standard bar ends so kill two birds with one stone for me