Windshields and Buffeting!

[mcgovern61]

Pics as promised:

 

[mcgovern61]

Test ride with my HJC 3/4 helmet at 75 MPH and no noise at all! What a pleasure. No ear plugs needed now. :yes:

There is wind that obviously gets past on the sides (which is great for keeping cool), but no head beating on top or back of the helmet.

 

[mcgovern61]

mcgovern61 » Sun Jul 31, 2016 7:12 pm[/url]":2dr0nt0w]
The Plexistar 2 is shorter by 2", does not have the extensions, is smoked (which is kinda cool), and has a wider opening at the front without the rubber moulding. :read:

First thing I did was set it up exactly the same as my current shield. Out on the highway, air is blasting up from underneath without those extension. It is creating a real low pressure area behind the shield and I can really feel the air blowing nearly straight up behind the shield from my knees up. :heat:

Next, lower the top until it was 2" below my eyes. Back onto the highway. Holy mackeral! If that is supposed to be smooth air I am in trouble! It was blasting my helmet big time! :shock:

Next, follow the fork angle and drop it down to the headlight. Smoother, but still a lot of turbulence.

Lastly, raise it up, follow the fork angle with a little more angle towards me, but raise it 1 1/2" above the headlight. In this position, I am now looking through the shield. It is about the best I could get, but still getting hit in the head with buffeting even though I have made adjustments and checked the air flow with my hand during riding to find that sweet spot.

Face it, the reality is, if I can get a sweet spot with the air at the top of the shield, the air coming under the shield cancels the effect and keeps the helmet buffeting. The lowering until the eyes are above the shield would wear me out on a long trip real fast.

Looks like I'm keeping my Plexifaring III on for now! I am not done experimenting yet, but that is it for today. :moped:

That is right. I had to take the step of finding out if the MRA extender would help a Plexistar II?

 

[desertrefugee]

My only complaint would be not being able to ride looking "over" the shield - which is usually preferred. (Slightly over). It looks like with the extension, you'll always be looking "through" it.

A technique that the Valkyrie guys use (I haven't since I don't find buffeting a problem) is to kick out the bottom of the shield about an inch. This tips back the shield at more of an angle and, reportedly, improves airflow and reduces buffeting. Again, I haven't found buffeting to be a problem, but I can tell you that the look is pretty cool. My buddy has his done. He just fabricated some simple, small brackets for the bottom mount points.

Here's a shot that shows the difference in angle between mine (stock) and his, kicked back:

 

[mcgovern61]

Recap.....the Plexistar II is smaller and shorter than the Plexifaring III. I have been really enjoying riding around with the MRA Extender on the Plexifaring with no wind noise or buffeting. My daughter has verified that even the rider has no helmet buffeting now.

The '81 1100 also had a Plexistar II and just like the one I tried on my '82, the Plexistar II has buffeting and turbulence issues. This weekend, I decided to put the Plexistar II back on, but this time with the MRA Extender added.

Ride report:

After some minor adjusting, I was able to get the MRA in a position that did not cause visibility issues. With the Plexistar II being almost 2" lower than the Plexifaring III, it creates a line at the top of the windshield where you are trying to look over and see the edge of the windshield. I moved the windshield towards me to lower it a bit more to get that line out of my line of sight. The MRA is clear, but the outer edge is thick and can also produce a line of limited visibility. It is highly adjustable so I was able to get it low enough to clear my line of sight and stay high enough to work as an extender.

To my surprise, the MRA really worked! It smoothed the flow of air to the point of nearly zero turbulence or head buffeting. Jumped out on the highway at 75 MPH and it worked terrific! My only issue is the line of sight with the actual windshield. You still have to look over the edge which is annoying to me. But the MRA Extender really tames turbulence and buffeting!

 

[slabghost]

Looks cool too.

 

[Ansimp]

Looking good Gerry. :good: