Originally Posted by marc
You've two extremes that will leave your helmet in clear, smooth air. You can go no windscreen at all or you can go with a barn door, AKA aeroflow. Everything else is a compromise. I dislike the aeroflow for reasons that have nothing to do with its effectiveness. No windscreen was a bit much, so my compromise is a cut down stock screen. It put my head mostly in clear air, but dumps a bunch of cold on my chest. So in the winter I clip on an extension which makes my chest warmer, but moves the rough air up into my helmet.
Only you can decide how much to compromise and in which direction.
My previous bike [a star warrior] had no windscreen and wind noise [at least with my prior fairly quiet helmet] wasn't really an issue. Wind blast was. Not having to 'hold myself' on the bikes like before now that I have a windshield is amazing and makes even mild rides (20 miles) more enjoyable. Now I'm just fighting the apparently inevitable buffeting/noise issues that come with putting a chunk of plastic out in front to block the wind.
I think I'll see if I can find a way to try a vstream. Until then, I think I need to experiment with different heights on my stock windscreen. Because of my height I immediately put it in the highest position assuming it was a must, but now I think I might need to lower it and see if that helps. I might get more direct air on my helmet but perhaps it won't be as turbulent and I'll still get the benefits of no direct chest/torso wind blast.