Several years ago, when we could still post pics on this website, I posted info and pics on my modified windshield lowers. The pics are long since gone, and I have since made the concept a little simpler, using just one flat Plexiglas plate, rather than two abutting plates.
Like many people, I had tried several windshields, trying to eliminate the buffeting. I solved this problem, and posted the info. In response to a recent post, I responded several times. This new posting is a consolidation of my replies, to make it easier for people this info in the future, if they do want to find this, on how to make your own windproof lowers system. Therefore, I may repeat myself a couple of times. Sorry.
I have a 2002 Bonneville America, and am 5 ft 10 in tall. Hope this helps someone.
The biggest (and cheapest) major improvement to a windshield is to stop the airflow underneath the headlight, which rises up over the gas tank, and causes turbulence. I use a standard Memphis Shades Alley Cat, with an extra 1/4 inch clear Plexiglas plate, mounted across and underneath the headlight, secured by Memphis Shades Lowers mounting kit # MEM9887. This plate is mounted to rise up and in front of the windshield, so that it passes all air up and over the windshield. I have been using it for years. There is absolutely no buffeting. There is a real "cone of silence" with no wind at all" for the rider. Also, since it is made of clear Plexiglas, it almost appears invisible on the bike.
The standard MS lowers don't quite do the same thing, since they do not block the airflow from coming under the headlight (and passing over the gas tank). That is the major source of the turbulence. To block it, you must make your own Plexiglas plate/air dam. It makes a world of difference, even over using the MS Lowers.
The Plexiglas flat plate extends between the brackets and UNDER the headlight. Actually, my Plexiglas flat plate only extends as wide as the lower part of my windshield, so if you don't look closely, it just looks like a long (low slung) windshield. The key to making it work though is to overlap the Plexiglas flat plate, so that it is in front of the lower edge of the windshield, thus forcing all the air upwards in front of and over the top of the windshield.
I tried making the plate wider and lower (longer), but it does not make any difference. To protect the knees, you would have to laterally add a piece of right angle (like angle iron) made of Plexiglas, to the bottom of the plate, to split the airflow and force it under the knees. However, I don’t know where to get “angle Plexiglasâ€. I guess I could just try to glue a one inch flange across/laterally to the bottom of the Plexiglas plate to accomplish that, but I just have not done it yet. Maybe I will try that before next winter, as I ride almost every day (commuting).
Lower Flat Plate-Side View Lower Flat Plate-front view Lower Flat Plate-front sideview --Tom
