My experience with the tall Zero Gravity Sport Touring wind screen on my Ninja250 and the tall Givi screen on my PCX150 has shown that you can achieve near silence from wind noise but you have to have the top of the screen high enough so that your helmet is almost entirely below it which means you are looking through the wind screen. Which is a compromise on vision when riding in the rain. Many large touring bikes such as the Goldwing have a tall, look through, windscreen height so I guess you get used to it but I find it distracting to have the extra layer of water droplets and road film in the way of my vision. You can't reach up to wipe the front of your wind screen while riding as you can your face shield. It rains a lot where I live. The position I prefer is to have my sight line just above the top of the wind screen and less than a foot to the rear of the edge which creates an air flow that blows the beaded water straight down and off my visor. At speeds greater than 40 mph, I never have to wipe my visor even in pouring rain. And a dirty screen is not blocking my main vision It is not quite as as quiet or aero but my visor remains beaded and clear even in cold fog.
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If building a solo streamliner from a clean sheet, I would use the two position flipping seat that Kraig Schultz is using. You can sit low, under the screen for maximum aerodynamics, comfort and lowest noise, or sit up just above the screen in traffic or bad weather for the best visibility.
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Schultz Engineering - Building a Two Position Electric Motorcycle
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