Nissan Patrol 4x4 (Africa)

I am just about to install my inherited roof rack, and this is the first time I am using a roof rack. The wife has given permission for an awning. One thing I like to do, due to the nature of our driving in the sand dunes here, is reduce the weight on top of the roof. Now a small awning is about 10kgs from a reputed manufacturer, TJM, ARB, Ironman etc.

Is there any issue with putting sheets of carbon fibre under the roof rack that slide out when needed as an awning, and can use a double sliding mechanism, such as in the picture below. Carbon fibre sheets are fairly cheap now.

Carbon fibre sheets are light and strong, and can use multiple sheets that slide under each other to slide out.

My question is whether the solid sheet of material under the roof rack will cause an issue whilst drving around 140kms/hr?

Have a look at peter connans plan I use this one all the time. ...in moz the wind can get from nothing to howling in 5 sec and that kills most of the available ones . The awining has got steel legs with canvas cover...gets put up and down in a min tops

I expect you would want to have the sheets slide back into an enclosure otherwise they would just collect sand between them and add a few kgs and those slide rails do not like getting sand in them. That would also solve your high speed issue.

Wind is a big killer of these things and I doubt a slide rail and carbon fibre would fair better than a well made awning. I know that the awnings that require pegs and poles are a waste of time on the sand unless you carry around bricks... a good 270 degree awning.

I think steel is out of the question for your application as you want to keep the weight to an absolute minimum on the roof. Peters awning is indeed strong, but with strength comes weight.

The carbon fibre sheets can work however, traveling at any speed ( above probably 30-40Km/h) the sheets would start to slap up and down like a flag flapping in the wind. One would need to reinforce the sheets as the sheets would probably be around 3m long. This doesn't sound long but drive down the road at 60Km/h and stick your head out the window and feel the force of the wind on your face /head. At higher speed this will increase dramatically. If you have ever been on the back of a bakkie ( pick-up) at 100Km/h, it is even hard to breath when facing the wind.

Although CF is an incredibly strong material, it is also flexible to a degree. This flex may cause the sheet to bang/slap the underside of the roof rack causing a very irritating noise, and damage to the CF sheet and roof rack. So in conclusion, I believe it can work, but black is also NOT a colour you want to have as the sun makes that into a griddle iron and you will probably be able to cook some juicy pieces of meat on it considering the temperatures you get up there. So a reflective upper paint coating is a must. Reinforcing is a must, and some form of cage or box for the sheets to slide into...... BUT here again you are adding weight that you don't want. Possibly a CF box for the CF sheets to slide into may be an option.

Yes the wind issue at high speed is going to be the challenge to control, perhaps hence why racks don't have a solid floor. Dust issue is valid too, but CAT gold is wonderful grease used here by our construction equipment and now desert rally cars.

The weight in an awning is not in the canvas, but in the frame.
My awning weighs around 20kg, but the canvas is only about 2-3kg (I use a lightweight material known as Poly-Oxford). Most of the rest is the frame. The awning is a 270 degree design with a 2m leg length and a metal box into which it folds. I use that because we have lots of thorn bushes here.

By removing the box, you could probably save around 4-5kg, and if you can find somebody who can manufacture the frame in 6061 Duralumin, I am sure you can get it down to 10kg or so.

I doubt the carbon fibre sheet awning can be made this light, as the carbon fibre is too flexible to operate without a frame, and will be considerably heavier per square metre.

Carbon fibre awning.

Worsboom.

Expensive...

If you are wondering, this is a Worsboom:
With its pods:
They can do some damage when they fall on something.

We went to the Berg over the weekend (for the annual "Run the Berg" race) and camped near the Amphitheatre.
Had a great time. The camp site is full of pine trees.
Every now and then a dennebol would fall to the ground causing the earth to tremble just a bit (don't know what a dennebol is in English).
The pine trees are tall.
Anyways, it was clear to me that if such a dennebol were to fall on one's head, it would not be pleasent at all.

I. worsboom or no worsboom, think the awning would have helped.

Ok from the rooinek It's called a pine cone old chap