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Old 04-14-2013, 07:06 AM   #1
jaTillApan OP
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A n00b building a mini rally fairing for a 690

I want some more wind protection on my 690 enduro for longer trips. The problem is I haven't really been able to find a fairing that is both good looking and affordable. I really like the look of the Rally Raid kits with tanks and all, but it's just too expensive and also a bit on the heavy side. And for a sexy bike like the 690 it would be too painful to go with a cheap but ugly solution. So I came to the conclusion that it might be best to try to build my own. I have never done anything like this before though, so all feedback is more than welcome!

My plan is to build the fairing out of carbon fiber and attach it somewhere at the fender, forks, handlebar clamps or whatever suits the design I settle with. As I don't have access to a workshop I think the mounts will be the hardest parts to fabricate so I want to keep that simple.

Well, lets get to it!

Yesterday I took some measurements on the bike, did a quick flat paper mock up just to get a sense of scale, and started to work on a first design in the computer. After some negative feedback and a good nights sleep I realized it was actually quite ugly. So I started over today and came up with this design that (at least at the moment) I'm quite happy with. As a first draft that is... What do you guys think? Feel free to feedback on everything: aerodynamics, design, construction etc!



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Old 04-14-2013, 01:36 PM   #2
sprouty115
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Style is a personal choice, so if you are happy with it that's all that matters. My only thought would be to make a mock-up (cardboard?) that can be mounted to the bike so you can play a bit with the height and width to see if you're happy with the wind protection. Sometimes a little adjustment can make a big difference in turbulence.
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Old 04-14-2013, 02:34 PM   #3
Dino de Laurentiis
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Are you sure that's the best design for a clean airflow?
Sharp angles aren't necessarily the best way to move air smoothly. It's also quite similar to the 990 Adv fairing (only bigger), and lot's of people complain about horrible turbulence on those.

I really shouldn't knock it's aesthetics... ...but I really can't help it :p
It looks a bit unproportional (i.e. too big) to the size of the bike, and it's overall triangular shape, coupled with the headlights, make it look a bit like a Ku Klux Klan hood, only orange Form should always follow function of course.
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Old 04-14-2013, 02:56 PM   #4
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the ku klux ktm
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Old 04-15-2013, 12:32 AM   #5
jaTillApan OP
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Haha, thanks for the feedback guys!

I'm having a bit of a struggle to get it to look proportional to the bike. I guess that's part of the reason they build the rally kits to go all the way around the forks and attach at the "tank". To be able to make it high enough without looking stupid :P Because this one isn't particularly high. It just looks that way because the entire bike is so narrow. But I guess I should try to lower it a bit and make it a little wider.

And talking about aerodynamics I have no idea what's the best design, so that's good feedback. I should read up on the 990 adv fairing!

And it's interesting how much your view of things changes when you step out of it for a few hours. Now it doesn't look nearly as good as it did yesterday :P
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Old 04-15-2013, 12:54 AM   #6
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One other thought occurred to me, and it's another good reason to do a mock-up - line of sight. The taller the fairing the longer the forward blindspot is. Which means that if you miss seeing something in the road you may not know it until you run it over.
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Old 04-15-2013, 04:01 AM   #7
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Originally Posted by sprouty115 View Post
One other thought occurred to me, and it's another good reason to do a mock-up - line of sight. The taller the fairing the longer the forward blindspot is. Which means that if you miss seeing something in the road you may not know it until you run it over.
At first I did a quick paper mock-up and realized I could live with something reaching 60 cm up from the fender. This one is about 55 cm, so it should be alright. But yeah, once I've found a design I like I'll build a cardboard version to see it in real life. I guess that will be the real test. A 3d render can only get you that far...
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Old 04-15-2013, 04:24 AM   #8
Sean-0
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have you thought of keeping the height but using perspex as the top part of the faring

i am in the process of doing such here is my first try



used to be fiberglass to almost the top of the perspex ..i cut it down and added the clear ... it still needs work and then the better 1 will be made ...you can add slots to the bolt mounts to make it adjustable up and down to suit

just a thought
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Old 04-15-2013, 05:38 AM   #9
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Originally Posted by Sean-0 View Post
have you thought of keeping the height but using perspex as the top part of the faring

i am in the process of doing such here is my first try


used to be fiberglass to almost the top of the perspex ..i cut it down and added the clear ... it still needs work and then the better 1 will be made ...you can add slots to the bolt mounts to make it adjustable up and down to suit

just a thought
It's a good idea, but it adds to the complexity of the project. And I'm afraid I might end up with something half finished sitting in my apartment for the entire summer if I try something too ambitious...

But it's an interesting shape of that screen! It's a pretty extreme lip there at the top. How's the airflow from that one?
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Old 04-15-2013, 08:33 AM   #10
Motomochila
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You are going to have serious issues with that design unless you also design a mounting system that welds or clamps to the head stay. Mounting to the forks or triple clamps would not give you the desired wind deflection you are seeking. Have you looked at the lynx fairing? Although smaller, it does have a movable windshield that works quite well. At least look at the mounting process the lynx uses to aid you in your design.

Keep posting as you go forward.
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Old 04-15-2013, 11:20 AM   #11
jaTillApan OP
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Originally Posted by Motomochila View Post
You are going to have serious issues with that design unless you also design a mounting system that welds or clamps to the head stay. Mounting to the forks or triple clamps would not give you the desired wind deflection you are seeking. Have you looked at the lynx fairing? Although smaller, it does have a movable windshield that works quite well. At least look at the mounting process the lynx uses to aid you in your design.

Keep posting as you go forward.
From what I can figure out the lynx fairing attaches in a similar way to how I want mine to attach, turning with the forks. What do you think would be the problem? Will mine be too high and wobbly? And the wind protection can hardly be affected that much by how you attach the fairing, right? In speeds where you need a fairing your forks will hopefully point in the same direction as you are going :P Or am I missing something?
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Old 04-15-2013, 11:25 AM   #12
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Trying out a smoother and lower design today. Maybe a bit more proportional to the bike, and less orange Ku Klux Klan :P



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Old 04-15-2013, 12:19 PM   #13
sprouty115
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That looks pretty good. And I'm not really a fan of any fairing, so that's high-praise.

sprouty115 screwed with this post 04-15-2013 at 12:24 PM
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Old 04-15-2013, 05:21 PM   #14
Jan from Finland
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Quote:
Originally Posted by Dino de Laurentiis View Post
Are you sure that's the best design for a clean airflow?
Sharp angles aren't necessarily the best way to move air smoothly. It's also quite similar to the 990 Adv fairing (only bigger), and lot's of people complain about horrible turbulence on those.
I wouldn't worry about sharp angles. The whole point of a fairing is to create disturbances. It's not an aircraft wing. It's practically impossible to predict how well it works in your case by just looking a picture. You have to test it first. If fairings were designed to minimize turbulence we were all riding bikes with dustbin fairings.

Here is what KTM has come up.


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Old 04-16-2013, 01:15 PM   #15
Bruno T .
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The trail tech above ^ bit taller might look decent. Not too tall though.
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