Aluminum vs Carbon Fiber Tent Poles

[. .]

.355" d Easton FX Carbon Poles = .33 oz. and just over $5 per foot and must have a bend radius greater than 39". They are sold in 17" sections. As a matter of example, a simple 12' pole should weigh around 4 oz. and cost approximately $60.

[Rakesh Malik]

Thanks for chiming in, Clint!

I've wondered about carbon fiber tent poles a bit myself, especially since I switched to carbon fiber tripods a long time ago, and know from experience how strong carbon fiber can be.

I'm just glad that carbon fiber tent poles are in enough demand to justify dedicated R&D.

[brent mydland]

Ok, So the CF ones sound really sweet, but they are between 50 and 60 bucks. Do I really need them for normal 3 season camping(in my new Lunar Duo?)
I have been looking at the .344 Easton Nanolite Aluminum poles on questoutfitters.com and based upon my calculations i could get by with 6 of them for a total of just 92 grams(poles alone, plus extra grams for the tips and shockcord) when the CF poles weigh 101 grams(3.6ounces.)
So it seems like the weight savings would be pretty minimal on the CF, and the Nanolite Aluminum would only cost me about 20 bucks….
Are the CF poles that much better or necessary? What is the ideal thickness Aluminum pole one should have for the Lunar Duo?
Thanks!

[glenn fleagle]

• I’m a little worried as I am practicing set up for my upcoming Via Dinarica hike and recently bought the custom 6.3 CF pole for my Integral Designs Silver Shelter.     The pole bends quite a bit under normal setup.   

[Bob Moulder]

Yep, that’s a lot of bend!

Do you use trekking poles? One of them would work much better than this.

[glenn fleagle]

I don’t use trekking poles (old school i guess)
Never saw a need for them except as you say: They make good tent poles for this tarp/tent. And fording rivers. (don’t really want to get into the whole argument about them, I just don’t see that they are for me)

Anyway, I’m going to go with this pole (pictured bent above).
I’ve already used this tarp/tent without carrying poles on the CT and just picked up a stick near camp or when heading above treeline.

[Brad Rogers]

A pole with that much deflection would worry me.

[Bob Moulder]

How long is it, and is it fixed length?

If you are into MYOG it would be quite easy to make your own using some 9mm diameter 3K rolled CF tube, with some 7mm tube for ferrules if you want to make it in 2-3 sections. Then get all fancy and join the sections together with some 1.5mm bungee cord.    ;^)

An additional thought… with that much bend, that pole in the photo must be made of some really cheap pultruded CF that splinters easily. In a good blow it likely would not last long and would fail in a very messy way.

[JCH]

Glenn – with encouragement and advice from Bob, I made some MYOG poles for my Duplex that turned out magnificently…very light, very sturdy and best yet, exactly what I wanted.  I highly recommend going the MYOG route.  Poles are one of the easiest things you will ever make :)

[Cherian Thomas]

That’s an Easton Custom Carbon 6.3 pole. It’s designed to be used in hooped tents like the MSR Carbon Reflex. About the same stiffness as the .340″ Easton aluminium poles, and just not suited to this application.

I’ll third Bob’s suggestion.

[glenn fleagle]

OK guys.

THANKS so much for all the help and advice.
I guess I was under the impression that this pole was made for this purpose.
So, now, maybe I have to carry a trekking pole.
I am presently in Thailand and could never find the correct source of poles here.

And I leave in 2 weeks for the hike.

I did like the weight of the pole.

I don’t think there’s a hiking store anywhere near our start in Slovenia to buy a pole.
Maybe I’ll just tape a stick to the pole until I hit a store after a week or so on the trail.

Thanks again.  Fiddlehead

[glenn fleagle]

I have an idea guys.
I will gladly pay someone to make me one and send it to my niece in Gorham, Maine as she is going to meet me in Slovenia to start the hike.

I need it about 44″ long, broken down into 3 equal pieces (with shock cord inside)

I can pay whatever it costs via paypal.

Any takers?
You can email me at [email protected] might be better than putting it out here in public.

Thanks for the help everyone.

fiddlehead

[Bob Moulder]

Sending an email.

I have some scraps of 11mm and can make a 4-section that should weigh less than 3 oz. The pieces I have are not long enough for a 3-section.

[J-L]

As another option, MLD makes a pyramid tent pole for their Solomid:

https://mountainlaureldesigns.com/product/pyramid-tent-poles/

3-sections, 46” long. I have the Duomid version – it’s very strong, similar to my trekking pole.

Edit: check with MLD before ordering to see if they can ship it in time.

[Bob Moulder]

Here is one I made.

44″, 4x 11mm CF sections w/CF ferrules, shock corded together, 2.39oz (67g), folded length 12.5″

[Stuart Murphy]

HI Roger,

If the carbon fiber testing comes to fruition… Would love to see the following:

• an interpreation of specs (such as tensitle strength etc) AND real world implications (videos of tents bend/ breaking would be good)
• aluminium vs carbon fibre for a couple of diameters and applications (say tightly curved per tunnel tent vs dome)
• the efficacy of “double-poling” – what real world benefit does it hold (benefits to static strength are obvious how about resilience in the wind and breaking strength/permanent deflection as a result of wind), how about compared to thicker diameter poles?

Lots of variable here I know… I want to be able to read a spec sheet (from Easton say) and have some practical insight into how poles/diameters will perform in what conditions. While you may not be able to provide “all data points”, perhaps you can provide enough for the reader to make an educated guess.

Cheers

Stuart

 

[Jerry Adams]

Double polling not optimum

Weight of a poll is proportional to the diameter

“Strength” is proportional to the diameter squared

2 polls will weigh twice as much and be twice as strong

1 poll of twice the diameter will weigh twice as much and be 4 times as strong

[Matt V]

A pole of twice the diameter will also be (I suspect) 4 times as stiff, so it likely won’t work without adding the correct amount of pre-bend. It could be difficult to get the pre-bend right since it might not be uniform across the entire pole (it might need to be a tighter bend at the top, for example). Double poling doubles the strength and weight, but you don’t need to engineer new poles to make it work.

Easton has new Syclone poles that can bend an extreme amount without yielding or breaking. It would be interesting to see how that compares to carbon fiber, and even more interesting if we could buy some for our tents.

https://www.msrgear.com/all-season-tents/easton-syclone-poles

[Edward John M]

Hey Clint

Does Easton have any plans for even stronger CF poles in the pipeline?

I am planning a large basecamp tent for Australias snow country and so far have decided that only the 12.4mm poles are going to have the strength I need in a tunnel tent.

Certainly 9mm poles do not have the strength needed at a height of 2200mm as well as a dearth of suitable joiners to suit the larger sizes to make gothic arch frames.

[Roger Caffin]

Hi Stuart

Nice idea, but I don’t have much in the way of CF tubing of different diameters. The stuff I use, and trust, is 7.5 mm OD. That said, you can do most of the testing on the bench or even in a spreadsheet. Yes, the theory is sufficiently well-known that you can trust a spreadsheet.

The physics is very simple. While you are in the elastic region, you calculate the ‘moment’ of the tube, and that tells you the stiffness. The moment is proportional to the difference between the fourth power of the OD minus the fourth power of the ID, divided by the OD. That is why the OD is so hugely important. And as Jerry points out, a larger pole is always stronger, wt for wt, than double-poling.

Thereafter (when you get to the yield region), aluminium can crumple or crack, while CF will hold on (stay elastic) much longer before it yields. Mind you, when CF tubing goes, it really goes with a bang! Which is better? CF tubing wins due to its density advantage: about half that of aluminium. In either case you design your tent to prevent the poles from bending so far they break.

That said, one huge warning is needed. This only applies to 2-D wrapped CF tubing and wound-cloth tubing. You MUST have the CF fibers around the tube as well as along the tube. If what you have is cheap pultruded stuff (fibres only along the tube), little of the above applies, as the circumferential strength is then due only to the polyester resin. Pultruded tubing splits very easily, right along its length. Been there, done that (but not in the field!).

What about vertical uprights for tarps etc? You will need some serious overstrength ratings as you cannot protect the vertical poles from buckling.

Cheers

[Edward John M]

Which is why my earlier question about using different diametres of poles with the larger OD sections in the middle to resist this buckling force rather than simply using large section tube the whole height.when talking about centre poles.

I get it, I just have trouble working it out to maximise strength while keeping the total mass as low as practicable

For tunnels I would stay with the original diametre and go stronger rather than keeping the weight down by going the same strength and going smaller and lighter. If the weight is that low I figure I don’t really need a tent

[Roger Caffin]

OK. Yes, could be worth while having a larger centre section: that makes sound engineering sense.

Might be worth remembering that my 7.5 mm CF poles survived in one of my tunnels without any sign of trouble for a long night at 100 kph. Actually, they survived the previous night at 60 – 80 kph as well – again no problems. We slept just fine.

Cheers

[Edward John M]

Her’s another question then.

How much stronger [ ball park] would a 9mm CF pole be than a 9mm Easton alloy because TPT don’t give any information about the actual strength of the CF and Easton haven’t replyed to my email for information

Would they be the equivalent of 12.4mm for instance

[Roger Caffin]

Ah well now, that is a bit hard to say without measuring a sample – to justify some assumptions made.
You also need to define just what you mean by ‘strength’. Sorry, but it can mean different things to different people. I will use ‘stiffness’ here.

If we assume that you have some Easton 355 tent pole (OD 9.02 mm, ID 7.75 mm) and some good quality 2D wrap CF tubing of the same diameter, then the weight of the CF tube will be about 57% of the E355, while the stiffness may be ABOUT 10% higher.

I will assume that the 12.4 mm tubing you are talking about is the E490 (0.490″ OD). Here we have to make some WAGs (an engineering term meaning Wild Assed Guess). The weight of this in CF would about match the E355, while the stiffness could be (subject to actual testing) between 2.5 and 3 times higher. But testing could well prove me wrong – it’s a real WAG.

Cheers

[Stuart Murphy]

Hi Roger,

I was hoping the Easton guy might come to the party and provide you various samples.

Regarding strength:

The stiffer the pole the stronger it is? That’s what you seem to be implying above regarding the elastic versus inelastic phases when a force is applied. So you can’t have a piece of spaghetti with an aluminium  tent pole – one that is relatively easily bent but virtually unbreakable (including holding a bend as a result of suffering a “bending” force)? (Which has advantages and disadvantages for livability and safety in a tent I guess).

Did the Easton guy contact you?

If you just need single sections for testing, that’s pretty cheap from Tent pole technologies – put it on the corporate card, or I’d be willing to contribute to costs.

Cheers

Stuart

 

 

 

 

 

 

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