Dr.Shifty
Hi All,

Some time ago I did a fairly detailed analysis of the poor aerodynamics of my OEM tall screen.
http://www.indianmotorcycleforum.com.au/post/scout-aftermarket-windscreen-8310285?pid=1294201363
In that post I mentioned that I'd got a screen vent as on the Goldwing and planned to cut it into my screen.

It's done. And here are the pics.

I taped the screen for protection, marked out the slot from a template I'd made and started cutting. I had a rolled up towel under the screen to take the downforce.

Vent 01.jpg 


This is the kind of bit I used - it's called a Forstner bit and I've got a set of them. It cuts the perimeter and scrapes out the centre.

Vent 02.jpg 


This is inside the screen. I cut from the front first, then turned it over to get a clean inner cut.

Vent 03.jpg 


The bit scrapes the surface into thin pieces. The screen is Bayer Makrolon which is easier to work than I feared.

Vent 04.jpg 


The third hole is cut through.

Vent 05.jpg 


I cut from the front, then the back, and I'm left with this little disc and a nice clean cut.

Vent 06.jpg 



When all the corners were done I got the Dremel tool and started on the straights.

Vent 07.jpg 


And suddenly, an ugly great hole in the screen.

Vent 08.jpg 


And here it is cleaned up and finished. It took further work with matching up the vent in the hole to get the final shape. The final edge is finished with very fine sanding so there are no crevices to expand into cracks.

Vent 09.jpg 


Here is the outer part of the vent sitting in the hole. I had to cut it down from original to fit between my screen brackets. It's glued together with Bondic, an instant glue that uses UV light to set it.

Vent 10.jpg 


Here is the full installation. The shiny black part is the outer stuck to the screen with black SikaFlex, the grey is the inner part.
The inner part deflects air upwards through the slots or, by opening a door, air flows through to the rider.

Vent 11.jpg 


This is the inside with the door shut.

Vent 12.jpg 


And this is with the door open.

Vent 13.jpg 


I will put it on the bike tomorrow and give it a test run. Then I can let you know if it's all been worthwhile.
Cheers, Kim.

From Woodrising (no, nobody else has heard of it either)
Rides a Springfield Dark Horse
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V-Twin
Awesome job Dr.Shifty!!  Very professional look.  👍😀

And thanks for sharing the step-by-step write up as well.  Someone will tackle this project after reading your post.
Let's be kind to one another.
Melbourne, Victoria
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CHF10
Brilliant work! I wish I knew how to do my own mods and work on my own bike. Very impressed by some things I see people do! [biggrin]
Live free or die!
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Dr.Shifty
It's Friday lunch time and I've been out on the bike to see if all the work was worthwhile. It wasn't. [frown]

It was so bad I had to come home and make a toasted bacon sandwich to cheer me up. [smile]

I had taped some telltales inside the screen and then went out riding. Once again the telltales all pointed downwards and rolled around as the air coming over the top of the screen overpowered the air coming through the vent. Perhaps if the vent were higher it might have been able to generate some inside uplift.

I was also reminded of how bad this screen is for wind noise and buffeting at head level. The constant crackling of the wind around the helmet meant I was glad to get off the bike.

So it's thinking time again. The next plan is to cut it down a heap. Now that I know how easy the stuff is to work with I'm not worried so much about cutting into it. It's currently 60cm from the headlight cutout to the screen top. I can cut it down to 40cm easily. This will give me spare stuff to experiment with making a movable spoiler that tilts to the front a little and push the air upwards.

It takes me time to think through these things. I'll let you know how the next step goes.
Cheers, Kim.

From Woodrising (no, nobody else has heard of it either)
Rides a Springfield Dark Horse
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Tezza
Great job Dr. Shifty. I know how you feel. I've made many a project for my bikes and had to go back to the drawing board.
Good luck with the next stage.

IMRG  AU101238
Ulysses  25368

2017 Indian Scout
2013 Boulevard C50T
Penrith, NSW
Never lose your sense of humour.  [smile]

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Dr.Shifty
Since my last update I've made myself some lowers from polycarbonate. These have changed how the wind comes up beside the tank and onto my chest. The difference is surprisingly noticeable when riding with no screen.

With the tall screen on it's calmed down the turbulence against my chest but I'm still getting whip-cracking air around my helmet. I wear moulded earplugs when touring which will get rid of that noise.

I'd planned to cut the screen down and use the off-cut as a top spoiler. Before I go cutting I'm going to try the spoiler that came with another screen for my Kawasaki so see what difference that makes.



Lowers front.jpg 


Lowers rear.jpg 
Cheers, Kim.

From Woodrising (no, nobody else has heard of it either)
Rides a Springfield Dark Horse
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V-Twin
I can't wait to check out your bike in 2 weeks Dr.  Very creative!!
Let's be kind to one another.
Melbourne, Victoria
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CHF10
A lot of people (myself included when I started riding) don't realise that a lot of the wind they experience on their upper body is actually from wind hitting their legs and deflecting up. Lowers are more important than a windscreen if you want to minimise uncomfortable buffeting in my opinion.
Live free or die!
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