different helmets also will react differently behind certain shields.
without switching helmets, I'd go for a lower windshield

 

how old are you? what kind of shape are you in? do you exercise? do you do any neck exercises?. I ask this because if your neck muscles are straining to hold the wieght of the helmet and the pressure of the wind , it might be part of the reason your head is bobbing around. riding, in my opinion requires some physical stamina, I know a lot of people get on a bike and then find out they have issues related to this problem. I am not trying to insult, please don't take it that way. you may be in good shape, and its just the bike pushing extra wind onto your upper body, but it is something to consider

 

I get what you are saying but I dont think his whole head is bobbling around. Its just vibrating the helmet or glasses if you wear them.

I get the same thing on my EG. Its right at the top of my head. The only way to stop it on that bike is to look thru the windshield......If I put my feet out on the hwy pegs it moves the buffet down a little

 

This guy's got it right.

 

no he's not. I get buffeting from my lowrider's shield and my helmet is the right size. and it doesn't have anything to do with how strong yer neck is either

 

I wear one of those daytona non DOT helmets. No buffeting at all. But of course bufetting is part of the fun ain't it?

 

you must have a really strong neck

 

Quite a few people think they are wearing a properly fitted helmet when they are not.
I'm not saying all are, but to imply an improperly fitted helmet couldn't be the cause is ignoring a possible cure to his problem.

 

wind buffeting and your helmet sliding around on yer head should be 2 different things

 

laugh if you want, I see a lot of newer riders getting these big helmets and have issues with their necks, and back partially because they are in poor physical shape. its not a matter of having a strong neck, it a matter of being in somewhat good shape, and a whole lot of people aren't. so if you think I'm barking up a wrong tree go ahead, but its stiill a real issue