Carbon Fiber spreader bars

[Just Bill]

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.

History carries too much weight to describe it.
Very early on- somebody here familiar with Ruta Locura asked Josh to take a crack at a CF pole. Josh is good with CF but not a hanger himself and the bulk of his experience is in tent poles, trekking poles, and other applications.

He had a few sets that took some playing with, and a few to sort out the right epoxy method.
But for the most part he got it worked out.
He and I worked together to develop the sets for my bridges and we further refined a few things; including some better guidelines on pole size, user weight, etc.
So at this point... the collective effort has led us to a fairly decent understanding of what works.

There was one forum member who posted not long ago about breaking the head pole on his RR with some frequency- but I didn't get a chance to interact with him to find out more.
As I mentioned above... last time we got into it many of the problems that did happen had to do with folks over 225lbs or who had modified the RR suspension as for a while those two 'mods' were going on hand in hand.
Unless you're well under 180lbs or so you need to pick one- CF poles or trimmed suspension.

To Trail Slug's credit- there might have been a time I agreed with his sentiment but if you are buying from Josh and don't modify your bridge odds are good you won't have an issue.

The Ridgerunner uses a long bar relative to the width of the fabric- which puts additional load on the spreader bar as is, even with stock suspension.

While I like to pat my own back often enough... the reality is that most of my designs have a SUL origin and used spreader bars much lighter than others did at the time by a large margin.
So for me... the spreader bar was generally the 'weak link' and I had to resolve that. Most of the CF bars I use now are much stronger than the .490 AL I used on the micro and equal to some of the .625"
For Brandon... the spreader bar wasn't the limiting factor and he designed to resolve other issues. Or you could argue that his design smartly took advantage of the bar strength he was working with at the time.

It just is what it is. No sense blaming Brandon, Josh, or anyone else as none of them intended their gear to work that way.
We're the ones pushing things and have to be responsible for our own actions.

[hodad]

Josh beefed up the Ruta Locura ferrules. He initially shipped hollow ferrules. Since our early hx of breakage of the head poles we haven't had a failure in awhile, probably due to solid ferrules.

[Just Bill]

Josh beefed up the Ruta Locura ferrules. He initially shipped hollow ferrules. Since our early hx of breakage of the head poles we haven't had a failure in awhile, probably due to solid ferrules.

Are you the one I'm thinking of who had several failures or somebody else?

We're still using hollow ferrules in the sets I have Josh build for my bridges... but different animal than the RR.

[cmoulder]

I can't comment on others' experiences with CF different spreader/hammock combos, but the 3.6oz set that I made for JB's prototype do not at all feel as if they're on the verge of failing when loaded with my 167 lbs on them. In fact, in my first test of them (documented in the inflatable spreader thread) I bounced on them very vigorously and gave them a very respectable dynamic load. I slept on them one night and sidneyhornblower put at least a few nights on them, so there's something about this particular setup that is tweaked to perfection. But yeah, there's no way these are ready tobe unleashed on the general public!

[ilikemyhammoc]

A couple of things i found interesting.. of course bar length makes a big diff ( 2 inches can be "make or break" ) but also the arc of the "cat cut" makes a large difference. a more parabolic curve reduces forces quite a bit, combined with somewhat small size, long enough dog bones its not too bad i think (basically you're left with mostly compression forces instead of that and pull)
that said, it seems to me that a 18x15 is a safer all-around bar, though, im guessing its possible for the 16x15 to work out

[Just Bill]

I can't comment much on the exact wall thickness but generally-

(Using Josh's custom made tube sizes)
.610 series tubes I use for 36" or less and up to 225lbs. (about 15.5mm)
.710 series tubes I use for the 43" luxury up to 225lbs in a three piece. (about 18mm)
I want to say these are a minimum of 1mm wall thickness but I don't have a micrometer to measure them.
So likely 16/14 if you're pushing a bit and you're under 200lbs.
18/16 or 18/15 if you're a bit over 200 and can spare a few grams.

I'm as much as 235 depending on craft beer intake vs empty bowels ratios... so I say 225lbs as anecdotally safe in real life.
Static testing (by loading the hammock) isn't as useful in my opinion as dynamic loads from real people who occasionally bump the bar or do something a bag of cement just can't do.


As for the bridge-
You're correct, even an inch of bar or dogbone can be all you need to cross the line.
I mixed up the dogbones from my medium with a luxury size bridge and nearly snapped a pole (thankfully I saw my error and the flexing pole as I was loading it.)
Yes- playing with the curve or fabric length under the bar matters.

Overall- you need to balance the bridge. That's the best I can do to explain.
Exactly how you do that depends on your design. I have no way to put what I do to paper and run numbers on it to prove it; but as we carpenters say to engineers- it ain't falled over yet.

That said- if you're just looking for CF bars for cheaper (DIY)... better safe than sorry and going a little overboard will still likely represent a decent savings off of AL spreaders.
A 36" pair of AL is about 11 ounces
My medium set from Josh is 5.5 ounces
Cutting the weight in half and doing it yourself to cut the cost in half is plenty to be proud of.

What Cmoulder did shaving nearly 40% off the lightest CF set I've seen was amazing... and amazingly close to the limit I suspect.
With both folks around 175lbs or less in a balanced bridge as well.

That said... my ultralight philosophy has always been to find the edge of what's possible first. Once you know where the line is, you can take a step or two back from stupid light into something fairly solid. More often than not you've made a huge gain. You're pushing, but you're not doing it irresponsibly or to the point where your ruining every trip or puckering up everytime you see a storm cloud.

[hodad]

Are you the one I'm thinking of who had several failures or somebody else?

We're still using hollow ferrules in the sets I have Josh build for my bridges... but different animal than the RR.

Hi Bill, My Son and I went through a couple of sets several years ago. To be fare, we do a lot of backpacking, dump camping, and float trips with the scouts. We also went through a couple of WB's stock aluminum poles early on. Our newest pairs from Josh are holding up well. In-fact, my son completed the AT with a set of Joshes poles on his WBRR.
I've switched to a set with 4 poles of equal size and one middle pole to make up the length of the head pole. If I'm on a longer trek I'll take an extra middle head pole. I use Joshes 2 piece hiking poles which fit perfectly compressed on the foot section. This gives us redundancy at not much weight cost.
The 5-piece setup is also great for travel and will fit inside UL packs (Z-Packs Arc Blast, Zimmer Built Quickstep, and ULA OAM 2.0).

[Just Bill]

Thanks for the feedback!

It's my understanding that Josh has all the kinks worked out- but didn't want to steer anyone wrong as I'm not as familiar with what he does for other stuff.

My luxury uses a 43" head bar for up to 225lbs but I've tuned the bridges to reduce compression too.

I like Josh and like bridges- so happy to see everyone get good solid stuff. It's a huge upgrade worth doing in my opinion for anyone who backpacks with a bridge.