[pauljo]

Welcome to the forum. Of the screens I've tried, the Givi was the worst for back draft. Cutting a vent in it should help. The Clearview screens don't have as much backdraft, and I understand that they now make them with an optional adjustable vent already installed. The wobbling might be induced by yourself feeding small inputs to the handlebar as you are being sucked forward. The advice on going to a higher rear shock preload setting is also good - that usually enhances stability.

 

[pauljo]

I've always had a screen that I could look over. Well, heck, at 6'6" tall, nobody makes a screen that I CAN'T look over! :? But I was really surprised at the number of riders at Scootercade that had windscreen setups that they did have to look through, and they seemed happy with them. I think to be totally free of helmet buffeting and wind noise on the 650, you kind of have to do that - and for some folks that is a bigger concern than the "rain ride" issue.

The reason I say this is unique to the AN650, is because of that darn rubber nut mounting system that allows the screen to move back and forth a bit. As it does that, you get a certain amount of fluctuating wind slap at the top of your helmet - unless you've got it clearing the top of your helmet by at least an inch. The 400 appears to be a solid mount system similar to what my V-Strom uses, which I feel is a better design.

 

[pauljo]

The reason I say this is unique to the AN650, is because of that darn rubber nut mounting system that allows the screen to move back and forth a bit. As it does that, you get a certain amount of fluctuating wind slap at the top of your helmet - unless you've got it clearing the top of your helmet by at least an inch. The 400 appears to be a solid mount system similar to what my V-Strom uses, which I feel is a better design.

Hi Pauljo.

First I was under the impression that you did not ride fast enough to create a back pressure! :wink:

The 400 actually uses the same rubber nut mounting system. If a Givi is fitted to the 400, 2 additional metal struts provide mid line support but it does flex in the 'right conditions'.

Yah! I've got to talk to that Doug about the damage he is doing to my reputation! :wink: Actually, I have had the 650 up over 100 mph when doing windscreen testing - back before I went into "behaving mode" of course. And I still get into the 90's on passes occasionally. My current original design Clearview - and the prior Gustafsson windscreen - are narrower that the Givi and the newer Clearview designs, and there are no "hand wings". Back draft is not an issue with these. I think that the wider designs aggravate that problem. I'd love to try a vented Clearview - but not enough to pay for one right now...

I didn't look at the 400 windscreen mount closely - from a few feet away, my impression was that it was different. On my V-Strom, the base of the windscreen slides into a large slot and two screws hold it in place. Simple, effective, and NO flex. They have since gone to an adjustable height mounting system - I think it is also rigid, but I'm not positive.

 

[pauljo]

Dumb question, but are you sure your screws aren't loose? (LOL)

Screws are tight for sure. I've found that the amount of flex varies with windscreen design - and most certainly with riding conditions. On a Nebraska 2 lane highway, with folks traveling at 70 mph, an approaching semi truck can hurl a pretty mighty wind blast at you... A direct headwind on the freeway - or following in the turbulent wind draft of a truck, can also induce the flutter. At speeds less than 60 mph it is rarely an issue - but I do much of my riding at speeds higher than that. In a hilly and/or wooded area such as New England, or the Ozarks in Arkansas, the natural terrain breaks the wind most of the time. The wind blows often and vigorously out here in the plains, and there is no natural cover from it - so where you live and ride also has bearing. The flex is also most noticable with the tallest windscreens - the farther the top of the windscreen is from the base mount, the more it will move with the same amount of flex at the base.

 

[pauljo]

Today I also realized that I hadn't experienced at all the back pressure I experienced initially yesterday when I was going into the headwind. That was odd, but I was glad it wasn't there. Not sure what was different,

This has happened to me time and time again while experimenting with windscreens. I'll test ride - and everything will seem fine. I'll ride the next day and wonder if it's the same windscreen because all of a sudden I am experiencing excessive flex motion, or helmet buffeting, or noise. Mother nature is constantly changing the equation that the windscreen is trying to deal with... Unless you go with an excessively large (look through) screen solution, a setup that works satisfactorily about 80% of the time seems to be a reasonable target to shoot for.