Pazzo's Adjustable Windscreen Mod

The ULTIMATE 650GS screen has arrived!!!

Although quite satisfied with my modified GS tall screen Pazzo's Original Adjustable F650GS Screen some part of my mind continued to search for a solution that would allow me to drive well over 80 mph without visor or earplugs, and allow me to raise or lower the screen as required depending on on/off-road conditions. The solution should also be cosmetically acceptable and affordable. After my implementation, early summer 2002, of the modified screen I therefore kept checking out aftermarket screens as well as the original screens of basically any bike that crossed my path.

Now, almost two years later, I can confirm that the Ultimate 650GS screen solution exists! The ultimate screen is even a better fit than I thought: The answer to all problems is solved by the purchase of the tall screen of big BMW brother K1200GT.

Price and size

Let's start with the price: The cost for this screen is in the $100 range (I paid €92 for it in Holland). The price itself is already amazing: One easily has to pay over $150 for the average aftermarket screen, so getting a BMW screen for this price is terrific. The screen has a total length of over 20" and has a top section that is extra wide, with a curved top to further deflect the wind. Just like the original 650 tall screen it is made from cast polycarbonate. Being designed for the K1200GT it is certainly strong enough to handle wind pressure up to the 100-some mile maximum speed of the 650GS.

Design

The K1200GT screen has a bottom width that almost perfectly matches the width of the 650GS standard silver wind deflector. The wide top not only allows enough space for the 650 mirrors to pass when making sharp turns or locking the bike in Park, but even accommodates my Dakar handlebar protectors. After mounting the screen I was amazed how well it aligns with the 650GS shape, and even my purist BMW dealer found it a very compatible solution. The "lip" at the top further improves wind deflection and eliminates neck fatigue, allowing you to drive multiple hours with high comfort. The screen is specified by BMW as the "comfort windshield" (see part number below) for the K1200GT. Note: This screen is slightly different from the comfort screens of the K1200RS.

Comparison with other screens

I've tested the Ermax screen and similar Dakar screen. They both are too narrow and cause buffeting and have poor wind deflection. For that reason, I modified the tall 650GS screen ("Trevor style") to make it movable. This eliminated most of the buffeting but loses its effect above 75-80 mph. It also is too narrow, so there will still be quite some wind on your upper body.
The GIVI screen is no different than the tall BMW screen, so no improvement. I like the shape of the Wunderlich screen, but it is in essence not that much different from the Ermax or Dakar. It further is rather thin and does not offer the length to deflect wind above 70-75 mph.
The Parabellum is certainly more effective, but it has a poor match with the 650GS cockpit and also needs more work to mount.
Last but not least: The Cee Bailey's is a definitive step forward. With its 21" height it is the right size, but the lower mounting and rather narrow top makes it less effective and it is 40% more expensive.

The K1200GT screen beats all of the above screens by an order of magnitude. It is manufactured by BMW with thick, high quality, cast polycarbonate. It has an excellent fit, and does on the 650GS exactly what it does on the K1200GT: Eliminate virtually all wind up to around 100 mph.

On the K1200GT, the screen is connected via four cast mounting handles to levers that allow the screen to be either manually (K1200GT 2001/2002) or electrically (2003/2004) lowered and raised about 4" to make touring more comfortable. These four handles form part of the polycarbonate cast and offer a perfect match for the connection to the 650GS (series up to 2003). The two lower handles are just far enough apart to allow them to be attached to the upper screws of the standard 650GS deflector via two "Z" shaped thin steel mounting plates, while the two higher handles almost perfectly fit the metal bars that I've already used for my earlier tall screen modification. Material costs for the construction should be under $20. I started with a prototype that took an hour or two to build. After driving several hundred miles with the prototype I created the final version that is described below. With the drawings below you should be able to build this solution in a few hours (excluding paint work).

Driving test and Conclusion

I have now driven with the screen for some 1000 miles without any problems. Of these 1000 miles, 600 were done in a single day driving back and forth from Amsterdam to Frankfurt. Where, prior to this screen, I would have been quite tired after riding this bike for almost 10 hours (including a nice trip along the Rhine river, see pic below), I now felt great and would do it again tomorrow.

For my 6 ft height the screen is ideal. I expect that the screen will probably accommodate heights up to about 6' 4". I can drive with open visor and without earplugs at speeds up to 100 mph. No buffeting or other wind problems. The wide top also deflects the wind from the upper body, and eliminates side winds when making turns at high speeds, which are nice extras. The construction is very robust and has survived some basic off-road driving. Another side effect: The larger screen puts more pressure on the front wheel at high speeds and therefore reduces the tendency to 'lift'. Play around with the height of the screen once you've installed it. I noticed that the wind deflection from the curved top actually is better when the screen is a bit more horizontal (=higher wind speeds), so maximum height does not always mean minimum wind.

Needless to say this has significantly increased my pleasure of riding the 650GS, allowing me to hop on without bothering about ear protection and having comfortable long drives even in light rain, as nearly all wind and rain is deflected by the screen. One remark, based on experience: The curved top deflector was created to deflect wind only. Mosquitoes at 100 mph will not be much deflected, so eyeglasses are advised when you plan to drive with an open visor at these higher speeds.

Good luck and many enjoyable driving hours at 100+mph!
Gert ("Pazzo") 2004©AntarticaGalleries

Construction

Start with the screen: It is the tall version of the screen for the K1200GT. BMW part number: 46-63-7-663-115 (in US $ 91.50)

All other parts are depicted below. The nuts and bolts depicted below are self explanatory. You can reuse the screws from the standard 650 silver deflector. For the other screws you can use allen or other types, as long as they are stainless steel. The wing nuts and nylon washers should be supplied with the window brackets.

The two brackets on top are tall versions of the ones I used for my earlier modified version of the 650GS screen. They are brackets used for opening doors and windows and should cost you around $12 a pair. They are almost 14" long and 1/8" (3mm) thick. They're made of stainless steel.

Underneath the brackets, on the left hand side, you'll see the two polycarbonate (lexan) braces that connect the top two handles on the screen to the metal brackets. The wing nuts are mounted on the side of the brackets, and allow you to raise the screen to fit your length and lower it when you plan to do some off-roading. I initially used metal braces, but found the polycarbonate braces cosmetically nicer. They are just as easy to make from some scrap polycarbonate/lexan and offer additional flexibility, therefore putting less stress on the screen handles when you're off-roading.

On the right side of the above image, under the brackets, you'll find the screws with small plastic spacers that connect the brackets to the bike, replacing the screws just behind the Turn Signal mount screws (so, the 4th screw). The spacers (used in cabinets) provide the extra distance so that the brackets won't rub against the grey plastic fairing.

In the middle of the above image you'll see two "Z" shaped mounting plates that you'll need to make from thin steel (1 mm, or 1/16"). Make sure you use steel. Aluminum will not be able to sustain the bike's vibrations or needs to be much thicker. Bending these braces in the proper shape is the only key activity that is needed, so take your time. To assist you with this work, I've created a model of the "Z" below. If you're not comfortable using this model, don't hesitate to make your own model from a piece of cardboard. It only takes a few minutes to cut a model and it helps you understand its shape and the fact that the two Z's need to be mirror (!!!) image.

The "Z" plates are used to connect the top screws of the silver wind deflector to the two lower handles on the K1200GT screen. The reason for having the "Z" shaped profile is that I expect that, sooner or later, one of these handles of the K1200 screen may crack or break. This happens sometimes on the K1200GT when people try to adjust the screen at 130 mph, is what my BMW repair shop told me. While constructing the mounting plate you only need to spend a few extra minutes to bend the "Z" shape, rather than creating the more simple "L" shape. Should one of the handles of the screen come off you can mount the screen again by drilling a small hole through the screen into the mounting plate and using the nut and (self-locking) bolt to fix it again.

Use the model below to obtain the correct scale for creating the mounting plate (apologies for using metric here: 75 mm equals 3") and bend the plate according to the Z-shape on the right hand side of the drawing. I made the mounting plates from a single steel joist hanger with width of around 3½ " and similar bearing. They're available in any Home Depot or equivalent shop for under $2. After cutting the basic shape and bending it in accordance with the model, you'll need to drill the two holes on the indicated spots. The only time consuming part left is to (spray) paint them, but I suggest you only do that after you've tested them with the screen. In that case you'll need to be a bit extra careful with the screen. Polycarbonate/lexan is easily scratched.

As a newbie I do not comprehend the excitement of race bikers when there doing well over 200 km/h (120 mph). There is not a windscreen that will protect you at these speeds, so the best way to drive at these speeds is comfortably in your car (excuse me: I mean "cage"). My BMW 650GS came with the tall BMW windscreen. Above about 80 km/h, no positive effect is to be gained from this screen. I'm 1m80 (6 ft) and when I ride the thumper, the wind hits me just under my chin. Riding 100 km/h is already uncomfortable and 140 km/h (90 mph) is quite unpleasant and only useful for some quick passing.

As a newbie I had not realized this BMW screen was that poorly constructed, so I started browsing the internet again to figure out a solution. I found that there are three screens available (in Europe) that fit the (new) F650GS: The tall BMW screen, the BMW Dakar screen, and an Ermax tall screen. Multiple stories and theories existed on the web about these screens, with lots of impressions but no hard data. In addition to the commercially available screens there are also some non-standard fixes. I'll describe most of them below.

Based on info from the FAQ pages of the Chain Gang, I modified my existing tall F650 GS BMW screen by adding 12 mm (1/2") plastic spacers under the top screws. I had to make the two side holes in the screen a bit oval to allow for the new position of the screws. Easily done with a low rev drill. The more upright position helped a bit, but not a significant amount.

What to do next? Adding one of those little plastic winglets on top of my screen (made by Saeng) did not make too much sense to me. I played around with the idea to build the "jet compression" windscreen that was mentioned on the Chain Gang site. This was a story that seemed to have appeared in a German motorcycle magazine. When and where is not known and some charts that were supposed to show why the system worked were no longer present.

The document can be found here. It basically means that the author built a funnel on top of his screen. The funnel increased the density of the air and caused it to "blow away" the air that hit the screen from the front. Sounds logical, but how to build one? I have seen a somewhat similar gadget on an older BMW, but that strip was only 5 cm (2"). A funnel should be much longer to have any positive effect.

Out of curiosity I posted the basics of this story at an aerodynamics engineering site, just to see if one could design such system based on aerodynamics theory. The feedback from the experts was that this theory about a "23 degree air compression and expansion angle" was basically bullocks and that there were too many variables existing for any decent planning of such screen. Trial and effort seemed the only way forward, but if you realize that you will have to buy LEXAN (as used by BMW) or some other poly-type material at $ 150 per square meter, you'll need to make a mold for the form, and be proficient with a heat gun or use a temperature controlled oven to bend these 5 mm thick screens, you realize that this is not going to be an easy task. Expect to mess up at least two screens and a few days of work before you may have a useable prototype.

I admitted defeat and started to wear ear plugs. That did ten times more for the noise than any screen will ever do. However, I still would like to be able to ride about 70 mph without them. By the way, I have been using Wilson pilot earplugs for many years on board the plane (as passenger) to silence out the engine noise that causes most of the tiredness after intercontinental flights. They cost virtually nothing. Last batch I bought was at http://aircraft-spruce.com/main.html. Can't get any better and they're only about $2.

Anyway, having read multiple articles and comparisons between the BMW and Ermax screen I decided to give the Ermax a try. I ordered the "tall" transparent screen ($92 in Holland and had to be shipped from France) and received it two weeks later. Note: Ermax did not ship the long M5 screws that you need with the screen so I had to get these from my local hardware store.

Key difference: The Ermax screen is far more upright than the BMW screen and is a bit curved away from the screen at the top, which helps messing up the wind speed. Note that the Dakar screen has a much more curved screen top. Overall result is that the wind now hits me at the forehead: Altogether a 15 cm (6") improvement ($16 per inch). Still not enough to ride with an open helmet, but a little better when you're doing 70
mph. I did notice that the form of the Ermax causes buffeting. The BMW tall screen does not have this problem.

My conclusion is that the Ermax moves the "quiet" zone a bit up, but not enough if you're 1m80. I guess that Ermax caters for the French market where people are still a bit less tall than in Norther Europe. You will still need ear plugs. At speeds above 90 mph there is quite some buffeting. Everything basically starts to get blurred at that speed. Side wind from the screen hits the mirrors, which are sometimes blown out of position. If you're up to about 1m75 (5ft10) I expect the Ermax to be more effective than the tall BMW screen. If you're taller and already have the tall BMW screen or the Dakar screen, the Ermax is not worth the money. I noticed that the BMW tall screen is made from LEXAN (polycarbonate) while the Ermax looks made of thick Acrylic glass. It took only a day to get some scratches on the Ermax screen (and therefore couldn't return it to the store).

I installed the Ermax over the small stock screen that originally comes with the F650GS. While trying to get the right type of screws for the Ermax I drove around for a day with only the small screen, and concluded that up to speeds of about 50 mph it does'n matter at all if you have a screen or not.
Altogether I'm still looking for a more optimal solution. Now that I have two screens I will use the BMW screen to apply the "Trevor adjustable screen" solution (see below).

To get comparison numbers that can be used for future reference I measured the height of the screen by taking the distance from the top of the (fake) tank, a pretty stable element on my bike, to the top of the screen (vertical measurement only). Results: The tall BMW screen, unaltered, measures 32 cm (about 13") tank-to-screen top. My altered version (adding some spacers on top screws) has 38 cm (little over 15") tank-to-top.

Using the shape of the BMW tall screen I measured the maximum height that Trevor's adjustable screen will be able to go: 44 cm tank-to-top, so a bit less than Ermax. Trevor's height is 1m76 (5ft10.5), so that's why his screen is perfect for him. Since I'm 1m80 (6 ft) I guess I need about 50 cm (20") to be able to ride with less wind problems.

Rando has made a screen from a large old Slipstream screen. This huge screen solves all problems, so check out Rando's pictures. His screen measures just over 50 cm (20") tank-to-top and should therefore be the right solution for me as well. Problem is how to get a Slipstreamer screen (the right type of screen) in Europe in one week (I'll be going away for vacation with the thumper for the "As the crow flies trip"). So the answer lies in trying Trevor's adjustable screen.

My general conclusion from these measurements is that a very basic principle applies: As long as the top of the screen is at about eye level you will have significant less wind impact. It apparently does not matter very much how the screen is shaped and whether it has the extra top spoiler or not. The easiest way to see if your screen modification is successful (besides trying out) is to tape some loom to the top of your screen and see what happens with these tiny strings at different speeds. Raising the screen above your eye level is also an option, but in that case you need to raise it substantially higher (at least 10 cm / 4") above eye level to avoid visibility problems. This last solution will probably look a bit silly on an all-road bike.

I name it after the inventor of this solution. Have a look at Trevor's site with nice shots of his adjustable screen.

It took me a while to find the right hardware store for the drawer brackets. Most of them had newer versions based on a tube system. I started to collect all applicable bracket types until I found window brackets that would probably fit Trevor's description.

The top two are window brackets (2 mm thick), the lower two are brackets for cabinets. Looking at Trevor's site he used a longer version of the thinner "d" type bracket. My preference was to use the "c" type (also 2mm thick), because this is a single rod of steel and has a nice clamping system. The clamp, however, could not be fully fixed in place so I'll defer this system for a next round. The window brackets "a" and "b" were a bit too large, but had the advantage of being very strong and reasonably weather proof. A nice extra was that they already have all the necessary fixing material, including the wing nut and nylon washers. The price for a pair of nr. "b" was a mere $10. The lowest bracket is used for cabinets, has thickness of 1.5mm and is less weather-resistant, so I opted for bracket "b".

The work to transform two of these brackets into the components to mount on the bike was no more than an hour work, and basically consisted of sawing the M6 screw part from the bracket (see top row) and making the hole on the left in the bracket (2nd row) a bit wider. Since my screen needed to be about 5 cm (2") higher than Trevor's screen I added a hinge to the lower part of the screen. I bought two hinges and preferred the right one, but used the left one for this first prototype because this one was made of stainless steel. Price for the hinge: $1.50. An additional advantage of the hinge is that it avoids pressure on the screen when you adjust the height.

The brackets were a bit on the long side (30 cm - 12"), which I solved by mounting them on the 4th screw into the silver plastic moulding of the 650GS. I found this position a bit easier as it is behind the turn-light and therefore easier to mount. Just like Trevor I used a 1.5 cm (1/2") spacer o fit the bracket onto the screws and re-used the two tall screws from the screen to mount these brackets. The hinge I mounted to the headlight structure using the third screw from the screen. Besides the wing nuts which came with the brackets, I therefore only needed to add one M5 screw to connect the hinge onto the screen. This prototype still has a basic screw for the top mounting of the hinge. I plan to use some nicer looking screws in a next version.
Note that I mounted the tall screen on top of the stock screen. First of all because I found this better looking, and secondly because the stock screen reduces the opening between the tall screen and the lamp house and therefore reduces false winds. Worst case: If my adjustable screen crashes for some reason during my long trip I always have the stock screen to continue.

Below you'll see the low mount, with a cone-shaped plastic washer on the inside (left) that sells as a small doorstop. The rubber washer on the right side is a washer that is used in faucets. Low in price and very good quality rubber. The middle picture shows the stock screen with hinge, and the right picture shows the wingnut of the top mount on the inside of the screen. See release 2 version on next page for an explanation.

A 6mm hole at the corner of the screen is easily drilled in the LEXAN. The nylon washers that came with the window brackets fitted perfectly. I positioned the wing nut on the inside of the screen, mainly for cosmetic purposes. I may eventually replace the wing nuts by regular screws. The brackets needed a little bending by hand to fit the curve of the screen. The result is given in the pics below. Total amount of work was about 3 hours, most of which was spent in explaining to other folks passing by what I was doing.

The two pics on the left are the "Hinged Trevor" screen prototype. The picture next to that is the Ermax screen and the one on the right is the BMW tall screen (modified with spacers). I adapted the size of the pictures somewhat so that the "Mickey Mouse Mirror Ears" have about the same size. This shows the substantial difference between the adjustable screen and the two other options.

Future versions will have a prettier hinge, of course. That is a matter of finding a stainless steel hinge with only a single hole and which then will be shaped to follow the curve of the screen.

A noticeable reduction in wind at helmet level! The tank-to-top distance of this hinged version of the Trevor screen measures 51 cm (20.5""). I can drive 100 km/h (60 mph) without earplugs and with the screen of my helmet a little open. Wind hits me at the helmet just above the forehead and has much less power. This does not mean that there is no wind at all, but it is sufficiently less to take short trips (30 minutes) on the highway at this speed without ear plugs. With earplugs, speeds up to 130 km (80 mph) can be driven without too much buffeting. Because the upright screen is a bit further away from you there will be some buffeting, but the quantity is tolerable and much less than with the Ermax screen. The opening between the stock screen and the tall screen does not lead to false winds from below. In its highest position, the screen is just at eye level. I found that having the dark edge of the screen at eye level disturbs my vision on the highway and have therefore lowered it about an inch.

Altogether, Trevor's adjustable screen is a success! The modification is very inexpensive and can be done with basic tools and without being an experienced handyman. The adjustability of the screen will allow you to lower it quickly when you're planning to go off-road and want to get rid of the screen. You should not expect miracles from this modification, but the improvement is significant enough to give it a try when you're tall and like to ride over 100 km/60 mph with some more comfort. Worst that could happen is that you have wasted a few dollars in brackets and end up with two little extra holes on the side of your screen.

Improvements:
- Make the hinge better looking. I already closed the other screw-holes with polyester and will paint it light gray/silver and see if that looks better.
- Replace the screws in the top mount of the brackets by short slotted screws that fit the opening in the brackets. This means only the wing nuts need to tightened on the inside of the screen.
- Have both the brackets and the hinge galvanised for permanent rust protection. This is an inexpensive job, but usually has a return time of a week, which I do not have presently.
- Now that this works for the tall BMW screen I can try to do something similar with the Ermax screen that I now have as spare.

The Prototype Release 2

After two of days driving I found the time to make a couple of improvements.

These used to be composed of a screw and the wing nut. I replaced the screw by a bolt that locks into the bracket. This eliminates the need for a tool when adjusting the screen. The wing nut can be loosened by hand and adjusting the screen is a matter of seconds (but don't try this while driving). The special bolts will add the serious amount of $1 to the costs.

Now that the prototype worked out OK, it was time for some cosmetic changes. The unused holes were filled with polyester compound (left from an older car restore project) and spray-painted a couple of times with rust-protecting silver paint. The spray can cost $ 12, but this will be good for the next 100 hinges, of course. The picture was taken after one of those typical Dutch rainy summer days (and winter is worse). The paint was only one day old but held good.

More test results

In general, the adjustable screen with the hinge performs well. There was not yet time for an off-road drive, but it performed well on minor bumps like driving up the sidewalk. The only time when I could hear some noise from the hinge was when I drove full speed over some speed bumps.

I noticed that mounting the brackets on the 4th screw of the mould rather than on the 3rd, and the increased height of the screen in general because of the hinge, resulted in much more space on the inside of the screen. This allows me to put the wing nuts on the inside where they are less obtrusive than on the outside. The extra space also allows the screen to be adjusted downwards without the wing nuts hitting the top of the headlamp structure. They actually move over the stock screen.

One negative point needs to be noted: The higher screen takes a significant part of the wind away from the helmet. That's good, right? But it also means that raindrops will stay longer on your visor, since they are no longer immediately blown away by the wind. Now that the screen takes a larger part of your viewing area, raindrops on the screen will be more annoying as well. I consider both effects the consequences of luxury, but they need to be noted.

I have added a couple of shots below. Couldn't find a nice background, so this will have to do until I'm back from my vacation trip. The painted hinge starts blending in quite well with the stock screen. The wing nuts on the inside are virtually invisible.