Fabricating a Fairing

[Gbrebes]

Hello Everyone,

I took my first test drive last night with the fairing on. Things worked out ok. The side panels near my knees shook a lot during riding, so I will need to add brackets going from my bike frame to the fairing frame at the rear top of the fairing frame.

I was riding on the street and didn’t get going much past 45mph, so not sure if the fairing helps with top speed, but it was windy and I definitely felt the wind push my bike around. It was also a little squirrelly riding at speed, I realized how much I depend on the feedback from my front tire and fork movement to judge balance. Having the fairing blocking the view of the fork/tire really affected me. I’ll have to practice more with the fairing on.

Other than that, the fairing did not get in the way of the handlebar movement or my knees when leaning into a turn. So I think this shape will work out.

I tried to fit my paper pattern for the windshield into my oven and it does not fit. I understand the heat gun suggestion, but I want to heat the whole piece at once and that’s difficult with a gun. I might try to get access to a larger oven.

I finished shaping the wood buck, and I have applied spackle to it. So after final sanding, I’m ready for making the windshield.
Seeing the light at the end of the tunnel.

Gilbert

 

[Gbrebes]

Well, my second attempt at bending the windshield failed. I put this piece of lexan in the oven for 90 minutes at 250 degrees to “dry it out”, i then raised the temp to 450, and it draped pretty good, but there were wrinkles, it also got small bubbles. I guess this is trapped moisture trying to get out after heating, and is the reason for pre-drying. Guess I didn’t dry enough.

My first attempt I used a piece of acrylic and a heat gun, I couldn’t get it to bend that tight.

I may now scrap the full windshield and split the area into three sections, with a metal frame backing the seems.

I figured the windshield might be the hardest to make from scratch.

 

[Tom from Rubicon]

Hi Gilbert,
Your "Buck" my "Plug" wax it, apply mold release. Then lay 4oz fiberglass on it and brush on polyester resin. When cured trim with a scissors. What do ya think?
Tom from Rubicon

 

[Gbrebes]

It’s worth a try. Would the polyester resin dry see-through clear?

I really don’t like working with fiberglass, but I’m ready to consider all options.

 

[curtisfox]

Maybe make a small buck and keep practicing, with small pieces............Curt

 

[Venice Motor Bikes]

It's looking really good!!!!

How thick is the plastic you're using? (maybe thinner plastic will bend easier)??

 

[Venice Motor Bikes]

Another thing that might help with the wrinkling is to get some long flat clamps & gently stretch the plastic over the mold.

 

[Gbrebes]

I guess it looks good because it’s clear and you can’t see how many folded over wrinkles it has? In real life it looks like one of those tortilla bowls they make for tostada salad! You know those? They kind of look like a giant bottle cap? Either that, or I was going to say it has more ridges than a Ruffles chip.

Anyway, I am getting frustrated, and I appreciate the ideas greatly, but I need to finish this thing faster! The race is March 30th, and I still have to put on my race clutch and sprocket, put on race tires, test out a new restrictor plate on the carb, get used to driving with a big apron hanging in my face, blah blah blah.

No time for new bucks and testing, no time or desire to construct a whole vacuum form box, maybe time to try fiberglass? If my three panel idea doesn’t work, I will go old school aviation cockpit with flat plexi panels.

I have even considered just throwing Saran Wrap on my coat hanger form and just run that.

I’m getting desperate!

Gilbert

 

[Gbrebes]

The plastic i’m using is .093”, so around 3/32””, pretty thin.

Here’s a better look at the distortion of my attempt. The HORROR!!!

 

[Tony01]

It’s worth a try. Would the polyester resin dry see-through clear?

I really don’t like working with fiberglass, but I’m ready to consider all options.

Yeah it’s clear but cloth or mat isn’t. It does need a bit of strength but not that much. I can still sorta see my fingers thru two layers of 1.5oz (per sqft) mat and one layer of 6oz cloth. I don’t think just a single layer of 4oz cloth would be enough. I don’t have only cloth here, I have mat and mat woven with cloth. Next time I do glasswork on my build which will be soon I can try a test piece of mat/cloth weave and see what it looks like for ya. I don’t like working with fg either but I dove headfirst into it without any experience so I’m gonna finish what I started.

Also the amount of finishing to make it clear is gonna suck bigtime. You won’t get a nice finish unless you do a mold first and make it perfect. Even then it won’t be perfect. Dealing with lexan must be frustrating but probably easier than fg.

 

[Tony01]

The plastic i’m using is .093”, so around 3/32””, pretty thin.

Here’s a better look at the distortion of my attempt. The HORROR!!!

Yeah it’s pretty ugly. Try some .060”?

 

[Gbrebes]

Dang Tony, you don’t have to be so honest!!! Just kidding.

But wait, after I rough trimmed my lexan attempt, it doesn’t look so far off. I may try again for a full windshield with maybe acrylic, less bubbles.

Here is my next idea, splitting the windshield into 3 parts. It should alleviate the wrinkle pointts a little. I think I can get the three pieces to this new frame bent.

We’ll see.

Thanks for everyone’s input,

Gilbert

 

[Gbrebes]

Crappy, bubbly, wrinkly windshield on fairing.

It would block the wind! In a very ugly way, but it would function.

 

[indian22]

Crappy, bubbly, wrinkly windshield on fairing.

It would block the wind! In a very ugly way, but it would function.

Making a three section screen seems the closest solution at hand & the existing plug could be utilized to form each section individually in the oven, giving each section the proper curvature, while lowering the overall stress that was created attempting to form the screen in one piece & one heating. I'd think wood lathes could be employed to hold all sections in place while heating, as using metal hold downs would draw to much heat to the edges; or it's possible that wood or composition "washers" used at pre drilled points in the glass could be used to draw the sections to the plug with screws.

All this just for consideration to use with what you've on hand at this point and with that March deadline taken in consideration. Of course a multi pane construction with each section flat remains the quickest & easy method to clear vision & would look well also. Without vacuum & "even" heating employed I'm rather impressed by your results to this point!

Regardless I very much like the fairing and applaud your innovative efforts to this point.

Rick C.

 

[Tony01]

whatever happens Gilbert, I think someday you should try seeing what kind of top speed you can do. Clutch at 6.6 or taller and see if you can get into the 70s.

 

[Tom from Rubicon]

Norm made a good point about stretching and clamping.
About all the thermoforming of plastic I have done or built molds for, vacuum was used to pull the plastic onto or into the mold.
https://www.curbellplastics.com/Research-Solutions/Applications/Easy-to-Thermoform

https://hackaday.com/2014/10/19/diy-vacuum-former-on-the-cheap/
Tom from Rubicon

 

[bairdco]

Another option is, buy one. I've seen many motorcycle windshields on Craigslist for cheap. In fact, I have one sitting around that I paid five bucks for at a swap meet. You can have it. I'll get a picture of it later...

 

[bairdco]

Here's the one I have. It's 16" long at the center, 16" at the widest point. It flexes, too, so it might squeeze around to fit.

 

[Tom from Rubicon]

$5, Bairdco has a winner.

 

[Gbrebes]

That is very kind of you Baird. I will definitely take you up on that offer if I can’t get this 3 piece thing to work. Maybe even if the three panel does work. It would be nice to not have the two metal rails obstructing vision.