Factory flyscreen

Frypan, the picture in the laminarlip.com website shows a screen on the GRiSO that is not a flyscreen but a much bigger screen. Does the laminar lip you are using fit on your flyscreen, or do you have a larger screen (i.e. the one that is shown ion the website's picture)?

I have been looking for a lip, so this would be ideal IF it actually fits on my tiny factory flyscreen.

The LamLip is for the screen I have which is the one pictured. I see by your Avatar photo that yours is quite small. I thought my screen was small but yours is smaller. (Guys just leave that one alone)
If you send me the width dimension of your screen I can see if this LamLip will fit.

On my previous G11 GRiSO I had a Givi A770 windscreen that was just perfect. It looked like it was made for the GRiSO and worked exceptionaly well. Unfortunately they do not make that model any more. A770 If I had known that I would have kept my old windscreen when I traded for the G12.

Yeah, I know I have a small one. I will measure it tomorrow and let you know.

Another point of view, I have found the Flyscreen quite effective particularly at high speeds, obviously not as good as larger touring screens but still useful but then I am a shortarse so maybe that doesn't count.
In relation to the Guzzi Wind tunnel one of the reasons they don't use it, is that half the town has to shut down due to noise it generates which apparently can be heard from kilometres away.
Maybe the fairings were developed in a wind tunnel but it wouldn't have been the old one at the Mandello factory.

frypan wrote:

If you send me the width dimension of your screen I can see if this LamLip will fit.

Here it is.  Looking again at the picture on the website, I don't think it will fit.

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i ve juste unmount the original fly screen and appen to understand whay i had so much air i the eye whem my helmet glass was open
this fly screen direct air in my face. i'm 6 feet and 1.62 inches
i ve just bought the marlin dart one (the profile make's the GRiSO look like the Lemans !) , and will mount it this week end

Il ce fait tres bien!

Okay I finally got a chance to measure up.

My screen is 36cm across compared to your 25.5. The mounting pads for the velcro mounts on the LamLip are 28cm apart. These fall outboard of your 25.5. It looks like she no workie.

So in real terms yours is a 10 incher (across) and I've got a whooping 14.5 incher.

Thanks for checking. I guess i will have to look for something else.

After hearing that the factory flyscreen was unavailable for a long time I went ahead and ordered one form AF1, not knowing how long it would be available.  It just arrived and looks to be a quality piece.  But the mounting holes in the screen are not large enough for the grommet and spacer to fit through.  I notified AF1 and they reported all their stock has the same problem.  They are going to drill the right size holes and anyone receiving one from them should already have this problem fixed.  I'll report on my impression when I get the holes drilled out and mount it.

tod

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Please don't drill perspex (or whatever it is called near you) - drilling causes weird stresses around the hole which end up radiating into cracks with vibration.

This drilling process work hardens part of the material and other parts do not get this treatment. If you have to drill the hole, the best treatment is to put the whole screen into room temperature water and slowly heat it all up over a period of 8 hours and then let soak at 80 degrees C for 16 hours, and then let it all cool over 8 hours - quite a bit of effort is required.

We ended up doing this at work due to machining stresses - after we found out why each of our brand new perspex rods would fail within months, we scratched our heads till the blood ran out. Some research unearthed the correct annealing process which works well, believe it or not.

The correct tool would be a parallel reamer, or if not available a tapered one will suffice. Stresses are much reduced using either of these tools and annealing is not required. If using a tapered reamer, ream a bit from either side, so the narrowest point of the hole is in the middle of the material. Always go gentle, time is your friend in this process.

Hope this helps...

Tony is right about the stress created by drilling Perspex which is more commonly known as Acrylic over here. The stress relieving procedure is close to what I would do only I just use a special warm air oven. You can try using a solvent to melt the drilled surfaces in the holes. This is not as good as stress relieving but much better than nothing That said, the windscreen may not be made from acrylic but rather from polycarbonate, Lexan is one trade name, in which case you need not worry about the stress relieving. I would contact the supplier and find out what the material is.

Cory

Mine must be from the same batch, as the holes were too small in the same way.

Oz1200Guzzi wrote:

Please don't drill perspex (or whatever it is called near you) - drilling causes weird stresses around the hole which end up radiating into cracks with vibration.

This drilling process work hardens part of the material and other parts do not get this treatment. If you have to drill the hole, the best treatment is to put the whole screen into room temperature water and slowly heat it all up over a period of 8 hours and then let soak at 80 degrees C for 16 hours, and then let it all cool over 8 hours - quite a bit of effort is required.

Tony, do you drill the holes first and then do the heat treatment?

After posting the picture of the hole problem, I used a tapered reamer to open it up.  It took a little time but it was easy to get it to just the right size and no apparent harm to the material.
tod

Got thing mounted and went for a test ride.  I'm satisfied.  Looking at the size of the thing you can't expect too much wind protection but it does not give me nasty buffeting at the helmet level (I'm 5'9") and it looks good.  Had to ream the holes and the alignment with the bracket was not perfect but I think it is a rugged enough mount.  The folks at AF1 were good to deal with.
tod

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I installed my flyscreen (aka small screen?) on Saturday and went on two rides with it over the weekend. With a full-face helmet on I'm getting some annoying buffeting at helmet level when traveling over 100 km/h (~60mph) if I lean forward in a sports-riding position. I'm guessing this is due to my height (I'm a bit over 6'2). If I sit upright and back in the seat it is much better, but when riding wide sweeping corners I want to be able to lean forward, which has never been a problem with no screen.

Also I prefer the look without a screen. I like the flyscreen on the Ducati S4R but am yet to see anything similar for the GRiSO.

With an open-face helmet the buffeting is less obvious, but as I use both types of helmet I think I'll be removing the screen.

So is that Dart Marlin bigger than the factory small screen? I have the factory small and it's OK. Could use a touch more coverage in cooler weather, but don't want to look like I'm hiding behind a plexiglass wall.