Making the most of OEM windshield

[catalyst]

Hey all, I'm new to FJ 09.org, migrating from KawasakiVersys.com.  Still need to sell it! The Versys had a Givi screen on it and it did a pretty good job controlling noise and buffeting. I'd read that the stock Fj 09 was poor in performance,
but I really like the look.  After riding my FJ, I learned what everyone has been complaining about.  I'd also read about the trial and error of many other riders and many other shields.  I may have a better idea to atleast know what a shield is actually doing.
I taped 10" pieces of yarn to top, upper corners, and lower corners so I can actually see where the air is going at different test ride speeds.  That helped me tune the stock screen to best suit me. I'm 6'1" and use the tall seat setting.  Screen in highest position. Some of the posts I read suggested that having the shield away from the bike, allowing air under the shield, would release some of the turbulence.  The Givi on the Versys was that way.  I'd also read about owners using thicker rubber grommets to tilt the screen.  I went a different route. I removed the shield's mounting plate, or carriage, and added spacers behind that.  I started with four, 1" spacers, that simply moved the shield out.  I'm not sure if there was much change, even though there was now a gap for air to flow under the shield.
Next, I tried mounting 1" spacers at the top, and 1/2" spacers at the bottom to make the screen more vertical.  My redneck wind tunnel test ride showed the bubble, what little there is, and the turbulence as the air came over the screen. I think it's an improvement. Less pressure on the helmet, especially when turning your head to check the lane next to you. After that, I put the 1" spacers at the bottom, and the 1/2" spacers at the top, tilting the screen back.  In this position, the air flowed more cleanly over the shield and the yarn moved less as there was less turbulence.  The air was hitting me right in the chin and it must be what it feels like to ride the bike with a shorty screen.  No turbulence, but no protection either. If I turned my head to check the lane, there was a violent pull as the helmet was suddenly less aero.  As far as noise goes, I wear Ear Peace plugs and listen to music.  I think noise is going to be different for everyone because of helmet design, tolerance, deafness, etc.  However, protection from the wind was what I was after.  My conclusion is that using the 1" spacers at top and 1/2" spacers at the bottom with the screen more vertical, provides a small pocket of air for your helmet.  Less constant pressure on the face, and way less when turning your head.
The mod was simple. Two 1" long, .257 inner diameter, 1/2" outer diameter spacers, two 1/2" long, .257 inner diameter, 1/2" outer diameter spacers, two 6mm x 40mm 1.00 pitch hex head screws, and two 6mm x 35mm screws.  I put an angle on the side of the spacers that face the screen to help them fit more flush, compensating for the difference in spacer length.  If you think it's an improvement, let me know.

 

 

 

 

[koth442]

I admire your perseverance and 'can do' attitude. I chickened out and bought a CalSci

[2and3cylinders]

Other factors you have not included in your evaluation is the effect of the oem hand guards and, based on my limited sampling of every FJ-09 I've come across, is how the adjustable shield assembly has as much as 4~5 mm of fore-aft "play" that causes a rocking couple in the shield over pavement irregularities and fluctuating wind speeds and directions. Grab the shield at the top and push and pull fore and aft and you'll feel it.
 
I also added spacers and high durometer foam dampers on each side at the bottom behind the shield sub-structure but IMO the oem shield is a lost cause. The $25 Chinese double-bubble clone of the oem shield though has posibilities.
 
I now have a bikini shield for hot weather, the DB clone for moderate to warm temps and the Givi tour with A spoiler for temps below 75F.

[wordsmith]

Other factors you have not included in your evaluation is the effect of the oem hand guards and, based on my limited sampling of every FJ-09 I've come across, is how the adjustable shield assembly has as much as 4~5 mm of fore-aft "play" that causes a rocking couple in the shield over pavement irregularities and fluctuating wind speeds and directions. Grab the shield at the top and push and pull fore and aft and you'll feel it. 
I also added spacers and high durometer foam dampers on each side at the bottom behind the shield sub-structure but IMO the oem shield is a lost cause. The $25 Chinese double-bubble clone of the oem shield though has posibilities.
 
I now have a bikini shield for hot weather, the DB clone for moderate to warm temps and the Givi tour with A spoiler for temps below 75F.

The double-bubble I installed (AUD$30) definitely reduces, but does not completely eradicate, that fore-and-aft oscillation of the top of the screen.

[2and3cylinders]

The screen has no effect on reducing the fore-aft movement of the "slop" I am refering to in the screen adjustment mechanism.

[olddawg]

Impressed with your work. After about a year I switched to National Cycle V Stream Sport Touring windshield , it was a BIG improvement.

[Yamajank]

I want to cut a vent hole in the OEM screen to see if I can improve it.  That might lead me to cut one in the Puig that I use, but my question is what shape?  The way Calsci makes most of his is a kind of like a flattened "V" shape.  The one on the new Ducati multistrada is more like a simple upside down curve.  I've often thought that the older multistradas resembled the Tracer in that they basically share the one hand adjuster, and the shape of them are similar also.  Now I realize this new V4 multi is in it's own category.  And I know that Calsci has multiple degrees in physics, etc.  

[betoney]

4 minutes ago, Yamajank said:

I want to cut a vent hole in the OEM screen to see if I can improve it.  That might lead me to cut one in the Puig that I use, but my question is what shape?  The way Calsci makes most of his is a kind of like a flattened "V" shape.  The one on the new Ducati multistrada is more like a simple upside down curve.  I've often thought that the older multistradas resembled the Tracer in that they basically share the one hand adjuster, and the shape of them are similar also.  Now I realize this new V4 multi is in it's own category.  And I know that Calsci has multiple degrees in physics, etc.  

I think the idea with the vent hole is to lessen the effect of a vaccuum or negative pressure.  I didn't cut a hole in my screen but instead did what @catalyst mentioned in the original post and used 1" spacers to let a little air flow up behind the screen into the cockpit area. 

[Yamajank]

Just now, betoney said:

I think the idea with the vent hole is to lessen the effect of a vaccuum or negative pressure.  I didn't cut a hole in my screen but instead did what @catalyst mentioned in the original post and used 1" spacers to let a little air flow up behind the screen into the cockpit area. 

I did that too.  It helped some, I think, but I want to know if it could be better.

[betoney]

2 minutes ago, Yamajank said:

I did that too.  It helped some, I think, but I want to know if it could be better.

True, it never hurts to experiment.

[Yamajank]

The new Ducati isn't just a simple cut-out.  Darn.

[koth442]

A rectangle 1.5" x 3" would work well enough for you. The cheap / easy / quick would be a 2" hole saw. If that's the improvement you're looking for, go to town with a dremel and make it the shape you want.