2. PLEXIGLASS

Phase Five: Cut Once, but count Twice...

Or when try to measure precisely on 3D  curved objects can lead you to insanity! Especially on things partially asymmetrical like the F800GS face! The lines can seem wring but count right alla the time as the curves contrasted by the straight but uneven openings for the asymmetrical lights can easily fool the eye. Anyway where were we? 

Ah yes the finish... At some point you realize that the sanding painting sanding procedure can go on forever like a mandra. It soothes the mind but you loose track of the build. And the point is to see if this thing works with the bike and the wind. So mat black it is and on to the bike. You can always repaint, which by Merphy's old law will be needed if you finish it to perfection and then test it as a tool will slip and scratch the hell out of the paint. So:

I bought a piece of clear 4mm thick plexiglass, heat bend it, cut it sanded it and sand it to follow the curve of the base. 

Phase Six: Epoxy and Plexiglass -The Mariage 

Things go tough here as there are a zillion ways to get the one on top of the other, but I need something cheap strong and practical. So its shopping time again and back to the hardware store we go! I needed something cheap that holds but won't rust. So I picked up some aluminum curtain rails and some square profile aluminum tubes. I trimmed some nuts to slide inside the rails, so that the bolts could tight on them and the rails at whatever length I wish. 

Allen head screws, and although I thought to go with thump nuts, as some screen makers choose, the idea of someone unbolting them as they see him upfront there, and take the screen, even "for fun", made me reconsider. Who would take a plexisglass screen just for fun? Well I know a few people myself... Anyway with just an allen No 4, I can adjust the height of my screen for now.  Which is easy turned with the torx 25 on the bike's toolkit under the seat. 

I already feel that I need some kind of spacers to increase the distance between the black base and the plexiglass. Around 3cm high. I study the best fairings around, talk to people, and read some basics on aerodynamics. From what I 've read the airflow between the two surfaces has to equalize the air subpressure behind the screen. Otherwise the negative balance of air presure behind the screen, with that in front of it, will cause the air pocket to collapse, ruin aerodynamics, and minimize the cover from the air.  Will see...

And for those of us that get a kick out of numbers... So far we got: Total weight 1060 gr!

This is 100 grams less than a plexiglass screen in the same size! Thanks to epoxy, the heaviest part on the set are the bolts. Then the heavy part is the plexiglass. Should I go with 3mm thickness? Will see, but keep it as a mental note. At the same time the epoxy part is the strongest with maximum thickness less than 3 mm!

Phase Seven: On the bike

With the upper screen on its lowest point, we got 33cm from the upper headlight edge. For reference the total height of the F800GS original is 27cm. 

Upper screen fully deployed: 45.5 cm.

Maximum width at the base 46 cm. Maximum width of upper screen at the top of it 31 cm. 

 

Yes, it works! At least with the bike still it can travel freely up and down with two turns of the bolts. With mo extra pressure. With just one hand. And with motorcycle gloves on.

Next check, interfearance with bike's controls. Yeap thw bike turns full lock on either side without meeting the steering bar, the hand guards or anything else. Big deal?
        I would'n think of it as such, until I tested a screen -of a famous adventure brand- that on full lock to the left (yes the locking side...) the steering bar was hitting the screen. Go figure...

 

 

On our next episode: TAKE THE MF THING ON THE ROAD ALREADY!

Oh, and test it with strong winds,  on high speed, on rough terrain, and Oh, oh a gps mount, definitely a gps mount on it... and what about that bars they kind of kill the cool of the entire built... Will see...