Carbon Fiber spreader bars

[Just Bill]

soo i made the same bars of the same size, thickness, from the same seller and they all look good (its definitely rollwrapped aaaaaand im 170lbs (just like you) and the bars will break when i sit in ;-) its close, but they will break. Fun fact, if i attach the cordage the same way you do on the other post it definitely bends more than if i attach the hammock to the bar then the dog bones to the bars (instead of the hammock to the dog bones and the dog bones to the bar)

note its not bending at the end points, its in the middle of the bar itself - worse it's definitely bending just as much in the mid section where the joint is (which has way more carbon)



also note my bars weight is 115gr (so also a bit heavier than yours anyway, but i did beef up the tips a bit). and just in case: its definitely not my first time with carbon and of course the tubes have no damage or splint from cutting or anything like that Could also be a bad batch of course.

Attachment 175199

What bridge are you putting them into?

[cmoulder]

Hi Jeremy,

I'll jump in and admit that I got to play with cmoulder's carbon fiber spreader bars for a couple of months. I was dumbfounded when I first handled the 3.6 ounce set he made. I've used them several nights in a Just Bill bridge and had no issues at all. For reference, I'm about 5'9" and weigh around 160. I kept trying to think of some excuse so I wouldn't have to give them back after testing, but I couldn't come up with anything believeable. I also tested the hammock using the 3-section set, and in fact used them more often. Both sets worked without issue.

Indeed, the devil is in the details and unless you do things precisely and exactly the same way then I've done them, I can see how they might fail. For instance, if you use these bars with the warbonnet ridgerunner with those metal plates, all bets are off. Just bills setup is in my opinion the absolute Pinnacle of Simplicity and perfection. The design balances the forces perfectly.

[TrailSlug]

Yes these polls aren't worth the money nor stress of wondering when (not if) they are going to fail when used with a RidgeRunner. I just stick to my original polls and relax in knowing they've never failed.

[Just Bill]

Yes these polls aren't worth the money nor stress of wondering when (not if) they are going to fail when used with a RidgeRunner. I just stick to my original polls and relax in knowing they've never failed.

I believe they are speaking specifically of CMoulder's contribution.

I wouldn't hesitate to use Ruta Locura's poles if one is looking to cut weight. Josh makes excellent stuff with a good track record.

Other than some early kinks he worked out... Failure is very rare. There is one fella who mentioned several failures (and still buys replacements) but I highly suspect he modified his RR in some manner as the two 'upgrades' (CF poles and modifying the suspension) seem to go hand in hand. That's not an issue with CF poles- it's an issue with the bridge.

People put way too much emphasis on the dogbone to pole ratio being a magic bullet.
There is an entire bridge hanging in the air with an occupant inside... not one isolated 2 dimensional load diagram in the shape of a triangle.

[Dvankirk]

Yes these polls aren't worth the money nor stress of wondering when (not if) they are going to fail when used with a RidgeRunner. I just stick to my original polls and relax in knowing they've never failed.

Never had a problem with my carbon poles for the RidgeRunner or my carbon poles for the luxury. Is there a history of failure that I don't know about? I saw a post about a carbon ski pole on the forum, but don't recall seeing anything else.

[ilikemyhammoc]

What bridge are you putting them into?

A bridge I made - it looks similar to a ridge runner, 80 inches long, 36 inches wide at the widest ends.

Honestly a couple of things come to my mind, though these may be completely wrong:

- you have very long dog bones (mine are about 40 inches long) or have much more than 5 inches of 15x13 tubing inside the 16x15 tubes - i suspect if i had about 15-20 inches of 15x13 it'd be okay (this makes for a 16x13 equivalent)
- my tubes have some manufacturing defect that i can't see (that's quite possible, if the weave is damaged inside, or the epoxy on this batch is poor quality, or the 3k is more like 2k, etc)
- most likely a mix of these things ;-)

If not, I think i'd make them with 18x16 tubing, not much heavier but a lot stronger - or insert more 15x13 so that its going along most of the tube (but id have to unglue stuff which is painful , or just to get them from a non-ebay seller that are more reliable

[ilikemyhammoc]

I believe they are speaking specifically of CMoulder's contribution.

I wouldn't hesitate to use Ruta Locura's poles if one is looking to cut weight. Josh makes excellent stuff with a good track record.

Other than some early kinks he worked out... Failure is very rare. There is one fella who mentioned several failures (and still buys replacements) but I highly suspect he modified his RR in some manner as the two 'upgrades' (CF poles and modifying the suspension) seem to go hand in hand. That's not an issue with CF poles- it's an issue with the bridge.

People put way too much emphasis on the dogbone to pole ratio being a magic bullet.
There is an entire bridge hanging in the air with an occupant inside... not one isolated 2 dimensional load diagram in the shape of a triangle.

For the record if you're talking about me here (it sounds like you do):

The suspension i'm using is +- the same as CMoulder (https://www.hammockforums.net/forum/...=1#post1957633) ;-)

besides, this does not change the fact the poles are bending in the middle section. The tips are actually very strong and do not compress at all so I'm happy with the tips. And to be super clear, yes, my suspension is amsteel 7/64 and 1inch strap (dyneema as well), no metal pieces, and its not a ridge runner, though it looks similar in design.

Also: there is no way the bars I copied from CMoudler can support my 170lbs, but like I said it can be due to a variety of factors, not necessarily due to his design (in fact I'd probably design them the exact same way, just beefier). In fact, I'm currently using cheap aluminum poles from amazon and they work just fine, they're just a little heavier than I'd like (though lighter than the typical poles you get with an RR or other manufacturers).

I'm most likely going to source new tubes from a difference place to test, but i'm also going to have them slightly beefier, because 16x15 is very borderline strong enough regardless i think. I'm just curious what CMoulder thinks of this and how his behaved so far

[Just Bill]

The second post you quoted was directed towards Trail Slug's comment above.

I don't build Carbon Fiber poles- I source mine from Ruta Locura. He builds with at least double the wall thickness and his 36" bars come in about 5.5 ounces.
The set that Cmoulder built was a personal experiment in what was possible... not necessarily what was recommended.

I do build bridges- so that's why I asked what you were using.
I also sell bridges- so hope you'll forgive me if I don't spill all my beans.
I will tell you I broke lots of spreader bars before I figured out how not to break them.

Overall-
A bad batch of tube is possible, though I'm not familiar enough with the product to say how likely.
What seems much more reasonable to me as a bridge builder is to blame the bridge.
Not to take all the credit, but to help you resolve it; If you slapped the poles Cmoulder made into your bridge they would likely snap as well.
Sounds to me like sourcing these and waiting for them to ship isn't fun... so hate to see you waste too much time or money fixing the wrong problem.

Could I be wrong- absolutely. But seems we both more or less agree with the design Cmoulder used... and since Josh at Ruta Locura sorted out his CF poles to work with a RR originally I'd bet he also chose the correct wall thickness and pole sizes.

From an UL standpoint... because why else deal with Carbon Fiber
I'd have to imagine that you'd be lighter (and easier to build) if you increase the tube wall thickness rather than increase the ferrule length.
Besides diminishing returns there... I can add that regardless of material the diameter of the tube used seems the single biggest factor in adding strength provided the wall thickness is adequate.
Regardless of material (and including a few custom AL poles I built)... the 5" or so ferrule seems more than enough with rare exception. Nearly every commercial pole I've used sticks with about that size.
I did use a 9" ferrule on one custom setup of .490 Easton AL... but that was as much convenience in part cutting as it was any brilliant engineering choice.

[ilikemyhammoc]

The second post you quoted was directed towards Trail Slug's comment above.

I don't build Carbon Fiber poles- I source mine from Ruta Locura. He builds with at least double the wall thickness and his 36" bars come in about 5.5 ounces.
The set that Cmoulder built was a personal experiment in what was possible... not necessarily what was recommended.

I do build bridges- so that's why I asked what you were using.
I also sell bridges- so hope you'll forgive me if I don't spill all my beans.
I will tell you I broke lots of spreader bars before I figured out how not to break them.

Overall-
A bad batch of tube is possible, though I'm not familiar enough with the product to say how likely.
What seems much more reasonable to me as a bridge builder is to blame the bridge.
Not to take all the credit, but to help you resolve it; If you slapped the poles Cmoulder made into your bridge they would likely snap as well.
Sounds to me like sourcing these and waiting for them to ship isn't fun... so hate to see you waste too much time or money fixing the wrong problem.

Could I be wrong- absolutely. But seems we both more or less agree with the design Cmoulder used... and since Josh at Ruta Locura sorted out his CF poles to work with a RR originally I'd bet he also chose the correct wall thickness and pole sizes.

From an UL standpoint... because why else deal with Carbon Fiber
I'd have to imagine that you'd be lighter (and easier to build) if you increase the tube wall thickness rather than increase the ferrule length.
Besides diminishing returns there... I can add that regardless of material the diameter of the tube used seems the single biggest factor in adding strength provided the wall thickness is adequate.
Regardless of material (and including a few custom AL poles I built)... the 5" or so ferrule seems more than enough with rare exception. Nearly every commercial pole I've used sticks with about that size.
I did use a 9" ferrule on one custom setup of .490 Easton AL... but that was as much convenience in part cutting as it was any brilliant engineering choice.

I think your post is on point That's also why I'm curious about CMoulder's response, albeit he might also not be able to say as he was testing a product (I think it might be your product actually).

Also, yes, replacing the tube would be better than having a longer connection between the tubes, though its not as cost efficient at this point (but I might still do that). Oh yeah also, I won't want to pollute this part of the forum with non-warbonnet stuff, and I'll post that elsewhere when i got the bars working, but it is an UL bridge / 122gr without bars (and I'm not a vendor) for up to 200lbs.. well except for bars, so yeah. and yes, at least you micro bridge design (i just browsed your site) looks like it would put less stress on the bars already

[Just Bill]

I think your post is on point That's also why I'm curious about CMoulder's response, albeit he might also not be able to say as he was testing a product (I think it might be your product actually).

Also, yes, replacing the tube would be better than having a longer connection between the tubes, though its not as cost efficient at this point (but I might still do that). Oh yeah also, I won't want to pollute this part of the forum with non-warbonnet stuff, and I'll post that elsewhere when i got the bars working, but it is an UL bridge / 122gr without bars (and I'm not a vendor) for up to 200lbs.. well except for bars, so yeah. and yes, at least you micro bridge design (i just browsed your site) looks like it would put less stress on the bars already

Yar- Cmoulder had a prototype of mine that is out in testing that he lent out to SyndneyHornBlower to use as well. (which is why he chimed in).

Cmoulder can better speak to the CF questions... as perhaps you can as well, lol. I can't think of anyone else who has made their own CF bars offhand.
He and I were discussing trekking poles which he's been making for years so when the prototype came his way he figured he'd take a crack at some dedicated spreaders which really came together well.

And don't feel too bad as this (and one other thread) ended up being the default Carbon Fiber bar thread overall.
I've helped other RR users get bars with Josh (ruta locura) and regardless of who made it we all try to help each other.

I'm a big believer in SUL bridges- so keep up the good work!
122g for a body is right there with some of my lightest.