I took the 18" Jurock shield to a plastics manufacturer and paid $100 to have a 4" by 3" oval cut out of the center. By letting a jet of air through that oval, it reduces the updraft quite a bit but doesn't totally eliminate it.
The way it works is this:
The velocity of the air coming through the hole multiplied by the area of the hole is the volume flow rate. This volume flow rate also equals the area of the entire windshield multiplied by the velocity of the air on my side of the shield.
Here is the kicker....since the area of the entire shield is much much larger than the area of the hole, the air stream on my side is many times smaller such that it basically stops and just fills the vacuum thereby reducing turbulence.
There is one catch. I should have purchased the Jurock version that had the flip at the top as I am getting some top side buffeting that still is a bit too much. I could go back to the plastics company and have two smaller ovals cut near each top corner, but the optics of that seem a bit questionable.
Those of you who formerly owned an R1200C may remember the C-Bailey windshields. They had a cutout in the center to reduce updraft turbulence. You can see the cut out in the pic if you look for it.
Never mind the long brake and clutch cables. Ive ordered new lines and am using the king ape lines temporarily.

The way it works is this:
The velocity of the air coming through the hole multiplied by the area of the hole is the volume flow rate. This volume flow rate also equals the area of the entire windshield multiplied by the velocity of the air on my side of the shield.
Here is the kicker....since the area of the entire shield is much much larger than the area of the hole, the air stream on my side is many times smaller such that it basically stops and just fills the vacuum thereby reducing turbulence.
There is one catch. I should have purchased the Jurock version that had the flip at the top as I am getting some top side buffeting that still is a bit too much. I could go back to the plastics company and have two smaller ovals cut near each top corner, but the optics of that seem a bit questionable.
Those of you who formerly owned an R1200C may remember the C-Bailey windshields. They had a cutout in the center to reduce updraft turbulence. You can see the cut out in the pic if you look for it.
Never mind the long brake and clutch cables. Ive ordered new lines and am using the king ape lines temporarily.

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