Then I got the idea to use this “spoiler” as a mold to create a thinner, lighter spoiler with an edge around it. The plan is to slide the edge under the rear window rubber, the rear window rubber will hold it to the car.
Luckily I had an old rear window lying around in my barn. That was perfect for this project:
If I now put glass fiber cloth on it, it will become a spoiler with a small edge around it. With the same shape as the rear window.
Taped it with packaging tape, so the “spoiler” will stay in place, and it will prevent sticking of the polyester resin. On the packaing tape I waxed it with bee-wax. Then I put glass fiber cloth on it, en drenched it with polyester resin using a brush.
There are 3 to 4 layers of glass fiber cloth on it.
After it hardened, I just had to allready test-fit it on the beetle:
Of course it still has to be smoothed with filler.
It’s hold on pretty tightly only using the window rubber!
After a lot of filler, sanding, filler, sanding etc, a second test fit:
I like it!
The rear edge still has to be trimmed a bit, but it’s getting there.
how can you fix it on the glass?
I will post a link to the installation manual here, when I get home from work.
Hi Haman,
You can find the instruction manual here:
http://www.gerrelt.nl/roofspoiler/handleiding/instruction_manual_Gerrelt_rear_window_spoiler.pdf
The spoiler’s lip sits under the window rubber, and two short beads of sealant are used on the inside.
Greetings,
Gerrelt.
That sounds like a vortex generator , which may induce more drag than it reduces. My understanding of the roof spoiler is to provide a sharper cutoff to the airflow to reduce some of the drag caused by air partially detaching along the steeper back slope. By detaching the air completely you still have the full drag of the entire frontal area.
No, I don’t think it’s like a vortex generator. I think vortex generators are more for directing airflow to a rear spoiler.
It works more like a kammback. See: https://en.wikipedia.org/wiki/Kammback
The angle of the rear of a beetle is not good for aerodynamics. A long sloping rear or a cut-off rear (like a kammback) is better.
But this spoiler acts like the rear is cut-off just behind the spoiler.
Hi on the top part you can install a thin piece of metal and put it under the rubber slip it in and this will work awesome
I too am wanting a spoiler. I am redoing a 72 sb. Were you successful in producing more spoilers?
Hi Michael,
Yes, I even have them made by a fiberglass compagny now.
Scroll down this page for more beetles with the spoiler:
http://www.gerrelt.nl/section-aerodynamics/aerodynamics-roofspoiler-production
Greetings,
Gerrelt.
Thanks, how do I get one?
Hi Michael,
Sorry for the late reply, but I was on a (short) holiday.
I will send you the details.
Greetings,
Gerrelt.
Hello Gerrelt,
sent you a request for your roof spoiler. Hopefully you will still produce them. Looking forward to you reply
Cheers
Marc
I’ve sent you an e-mail.
Hi Gerrelt , can you give the price about your roof spoiler please ? possible to get it in full carbon fabric ?
Thanks
Guillaume
I’ve sent you an e-mail.
Hi, I want to buy one for my vw 1303 , 1973. Can you contact me please? Thanks. (find me on fb)
I’ve send you a facebook message.
Hi! Interested in buying a spoiler for my 1303s 1973. Would appreciate information about price and shipping etc. greetings from sweden, thanks in advance.
Anton
You’ve got an e-mail.
Hi Gerrelt
I am all so Interested in buying a spoiler for my 1303s 1973. Would appreciate information about price and shipping etc. greetings from Denmark, thanks in advance.
Kent 🙂
I’ve sent you an e-mail.
I would like to order one of your rear spoilers. What is the price with shipping to the United States (Georgia)?
I have sent you an e-mail.
Hi Gerrelt,
I’m also interested in purchasing a rear spoiler. Need shipping to the Utah, United States.
I’ve sent you an e-mail.
Hi Gerrelt
I like to order one of these spoiler for my Dad 1970 VW Bug. the rear window has a defroster in it! How much and can I get one real quick? flying to California on the 18th of November
You’ve got an e-mail.
I’m interested in your spoiler. I have a 73 Super Beetle going for the German Look!
You’ve got mail.
Hi Gerrelt! I would also like to inquire about ordering one of your spoilers for my 70 standard. Thanks!
You’ve got mail.
Hello Gerrelt,
I have a 1973 VW Superbeetle. How do I order a spoiler?
Best,
Darin
You’ve got mail.