HPV Carbon Fibre Fairing construction methods

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   Hi everyone,
I am currently researching the correct method for creating a fairing that will fully enclose my recumbent bike. I have chosen pre-preg carbon fiber as my material and was wondering if I could get any tips or suggestions from people who have made successful fairings.

The fairing will ideally comprise of two to three sections but if anyone has any more suggestions on the layout of the fairing sections that would also be greatly appreciated.

I also have a few questions:

What were your molds made from?
Did you use positive or negative molds to lay the carbon sheets? Why?
What fairing thickness is adequate?
How did you mount your fairing to your frame?

Thanks, 

Ben

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benwhiting Members Profile Send Private Message Find Members Posts Add to Buddy List Visitor (new) Joined: 09 March 2023 Location: New Zealand Status: Offline Points: 7	Post Options Post Reply Quote benwhiting Report Post Thanks(0) Quote Reply Topic: HPV Carbon Fibre Fairing construction methods Posted: 04 April 2023 at 5:44am
	Hi everyone, I am currently researching the correct method for creating a fairing that will fully enclose my recumbent bike. I have chosen pre-preg carbon fiber as my material and was wondering if I could get any tips or suggestions from people who have made successful fairings. The fairing will ideally comprise of two to three sections but if anyone has any more suggestions on the layout of the fairing sections that would also be greatly appreciated. I also have a few questions: What were your molds made from? Did you use positive or negative molds to lay the carbon sheets? Why? What fairing thickness is adequate? How did you mount your fairing to your frame? Thanks, Ben

russellbridge Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 21 October 2013 Location: Manchester Status: Offline Points: 843	Post Options Post Reply Quote russellbridge Report Post Thanks(1) Quote Reply Posted: 04 April 2023 at 12:29pm
	There's a very good book in the shop called 'So you want to build an HPV' which is a great overview of construction methods. https://shop.bhpc.org.uk/so-you-want-to-build-an-hpv There's also my video here of the design and build of my streamliner, although this used infusion rather than pre-preg: https://youtu.be/Qiaqktf-PEs A crash resistant, lightweight construction would be 2 layers of 200g carbon, 3 or 5mm nomex aramid, and then a further 2 layers of 200g carbon on the inside. One of the 200g layers could be swapped for Kevlar for added crash resistance, although this would fluff up if it were the outermost layer and you crashed. A single skin of carbon (whether made up of one, two or three layers) as the fairing would be lighter, but would wobble around a lot unless you had strengthening ribs (carbon over foam rods). These strengthening ribs could also form the mounting points to the frame if you're clever with their location. Hope that helps as a starter... Edit: there's also a recent Easy Composites video on construction of one-off items such at this fairing: https://www.easycomposites.co.uk/learning/mouldless-composites-laminating Edited by russellbridge - 04 April 2023 at 5:00pm

benwhiting Members Profile Send Private Message Find Members Posts Add to Buddy List Visitor (new) Joined: 09 March 2023 Location: New Zealand Status: Offline Points: 7	Post Options Post Reply Quote benwhiting Report Post Thanks(0) Quote Reply Posted: 05 April 2023 at 3:24am
	Thanks for your tips they will be very helpful. Also, after posting this message I realized that resin infusion will probably be better since the fairing is not intended to be structural.

GeoffBird Members Profile Send Private Message Find Members Posts Add to Buddy List BHPC Member Joined: 20 September 2005 Status: Offline Points: 2396	Post Options Post Reply Quote GeoffBird Report Post Thanks(1) Quote Reply Posted: 07 April 2023 at 8:43pm
	Hi, this is my account of building a fairing many decades ago. I'd go for wet lay-up initially - there is a learning curve with pre-preg and resin infusion and more kit and consumables required. http://www.bhpc.org.uk/Default.aspx?pageid=51&mid=70&ItemID=37 Edited by GeoffBird - 07 April 2023 at 8:43pm
	Right Time - Right Place - Wrong Speed