I have always had scooters and bikes with a windscreen. Ive just bought naked bike and can't see any difference between having or not having a screen. I got to thinking, the only way one can benefit from a windscreen is when the wind is coming from the front and is directly in line with the screen. If the wind is blowing in from the sides or any angle other than directly in front, the windscreen is redundant. Rain also falls almost vertically so again the windscreen is redundant. This is only simple logic, it would be nice if anyone had a more scientific explanation.