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Discussion Starter #1 (Edited)
I want to share my experience with my 650 at freeway speed after replacing the aftermarket windshield that came with the bike. Couple of days ago I completed a trip of 290 miles round trip ( 145 Mi each way ) at freeway speeds of around 65-67 MPH.

Since I got my bike I have been experimenting trying to find ways to mitigate the wind flow to my chest area at higher speed, freeway driving 65MPH, while reducing or eliminating wind buffeting around the helmet. After several attempts and different configurations here is what is working for me.

The bike came with an small aftermarket windshield (17IN W x 19IN T) I didn't really care for it anyways. While I like the cushion the shield provides against wind flow I was getting helmet buffeting at higher speeds, even sometimes at speeds of 45MPH. The adjustment process began, first thing I did was to adjust the angulation of the shield to different positions to no avail. No matter how far back or forward the shield was I kept getting buffeting.

So I started doing my research. First thing I did, I purchased Memphis shades fork deflectors. When I was done installing them, took the bike for a spin to open highway 55 MPH. Wind buffeting was less but still present around the helmet area, I had an incline I was moving in the right direction. Then one day while making adjustment to the shield I noticed that it was not curved on one side, rather warped, this is when looking down from above, my guess is from sun exposure. On the left of the shield (when sitting on the bike facing forward) the curved area was less than perfect, kind of looked a bit flat when it should have been curved.

I started browsing EBay looking for a replacement WS. I ran into a few OEM ones but I did not want to spend that kind of money on a shield just yet. Until I ran into a decent aftermarket unit. The overall shield dimension is 23 x 21 IN., however from the top of the headlight cut out to the top of the shield there is a distance of 16 IN, that's how shields should be measured. During the installation, as a starting point, I angled the shield to match the angulation of my forks. As for the height of the shield, in a straight horizontal line from the top edge of the shield towards me, this is while sitting in riding position, the top edge of the shield is between my nose and upper lip. When sitting on the bike I'm able to see directly over it at the road. The depth between the bottom of the shield and fork deflectors is 1.75 IN. It is worth mentioning that when I first installed the shield the depth of the deflectors from the shield was 1.50 IN., With that gap I felt air hitting my knees going up to my waist line when I took the bike for a spin, so at 1.75 IN., gap I get no air going up my leg. Again, this is what worked for me based on my body height, weight, shield, and fork deflectors.
Took the bike for a spin, reached 55 MPH - no wind buffeting around my helmet area, squeezed the throttle a bit more. This time the bike was at 60 MPH no wind buffeting, I squeezed a bit more, the bike got to 65 MPH. It took me several attempts to get it to work for me.

After all of the above, I was able to go 145 miles each way at a speed of 65 - 67 mph without buffeting and wind resistance. Aside from stopping to get gas and a bathroom break, my 650 ran like it could go all day long, she's a well oiled machine. Something else that helps is that the seat that came with the bike is a Mustang seat, very comfortable.

91952
 

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Glad you got it figured out. Getting the right height windshield is critical.

I had the same experience with my 950. The lady I bought it from was 4'8" tall. She had the short OEM windshield on it and it did absolutely nothing for me.
Got the Medium OEM windshield and it was a big improvement. Added lowers and it was even better. Adjusted the lowers closer to the windshield and BLISS.
 

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Great write up. This will be a good starting point for anyone in the future.
 

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it looks like you have a windshield and fork deflectors from two different companies

the windshield is over an inch forward from the deflectors, allowing the air coming up off the FD to go behind the windshield

also your FD are very high on the bike, overlapping (behind) by a good 6 inches

the goal of the windshield is to get a smooth laminar flow of air coming off the top and sides, that is thrown completely over the top of your helment, before it breaks down and goes turbulent and chaotic

if the turbulent air hits your helmet, thats when it feels like your head is in a paint shaker and your eyes wiggle and blur like jello (you cant read road signs) - that is head buffeting

to be clear, if you ride with no windshield you will get a strong blast of air pushing your head back, and it will be noisy, but that is not buffeting - the air is smooth and your eyes do not blur

the turbulent head buffeting from the laminar flow off a windshield collapsing into a vortex on your helmet surface is actually giving you a mild concussion while you ride

so... what you want is the WS to throw the air up and over your helmet

The ways to do that are:

1. have the windshield higher - if its so high you look thru it you will never get buffeting
2. angle the windshield more forward (flat) into the wind - that will aim the air coming off it up higher (steeper) and over your head
3. add lowers or FD so the air down by the forks gets a running start across their surface,which then continues up over the windshield in one smooth connected flow

with your fork deflectors up that high, and that far back from the windshield, you are losing the last part. You should be able to put them much lower

and depending on how your windshield pivots you might be able to lean it forwards so the bottom edge touches the top edge of the fork deflector - it might also help to put a piece of tape from the FD to the bottom edge of the WS, to flow the air across the boundry (if you cant make them overlap with the FD in front of the windshield

regarding the side to side angle of the fork deflectors, when standing over the bike and looking down over the windshield you want the curve (angle) of the windshield (side to side) to be matched by the fork deflectors - dont put them flat into the wind if your windshield is curved, match the curve at the WS bottom edge, like its an extension of the windshield down over the forks.

I messed with the WS and FD on my 650 all summer when I got them - finally got it to where there is no head buffeting at 85mph (wind speed is what counts)

and to where it does not back draft the exhaust fumes up into the air pocket - it does that a little bit now, mostly when I stop and take off again.

Have to say these standard style police bike windshields will never give you an nice quiet pocket, like a faired bike (Goldwing..FJR1300, New Venture...)

but they will stop the beating from the wind blast at 75mph
and they will make the bike warmer to ride when its cold - I put mine on when its below 50F

PS: if you lower the FD one thing to look out for - the bolts on the clamps point towards the fender - its possible to get the bolt low enough that when the shocks compress the end of the bolt will scratch the fender paint
 

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Discussion Starter #6
@KCW - I like your idea. This morning, while riding the bike to work, I was thinking about lowering the FD and get the top edge of the FD as close as possible to the bottom of the WS. The FD are memphis shades fork deflectors ( Measures 14in. L x 5in. W ). The WS is aftermarket from EBay. The nice thing about this setup is that the bottom curvature of the WS is pretty close enough in shape to the upper curvature of the FD. Basically, If put the top of the FD up against the bottom of the WS there's hardly going to be any gap between the two.

It will be a nice weekend project. Let's see what happens.
 
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