Lightest pack with a stay?

@ arc haul… Do you have a link for that?

Looking for a heavier winter pack for more serious conditions/terrain…

I'm not sure how helpful this will be since it's not commercially available, but at least it gives an idea of the potential limitations of weight carrying capabilities and light weight materials.

This pack has an internal aluminum stay (4 ozs for an XL 25" stay from GG) and combination of dyneema 210d and 1.4 oz/sqyd cuben. The internal frame channels are made using dyneema. The hip belt is 6" wide tapering to about 3-4" and made using cuben and mesh. There are pockets that fit 1/4" foam from GG.

I have used this with up to 35 lbs comfortably. The limiting factor for me is the hipbelt design. The pack weighs 18.4 ozs for the size XL and a better hip belt will probably add 1.5 ozs.

More info: http://seatosummitultralight.blogspot.com/2013/11/heavyweight-ultralight-backpack.html

BTW, I checked Zpacks for the Arc Haul but didn't see anything yet.

I don't have a link for the arc haul I don't think they are selling it just yet. I had read a few tidbits here and there on the forums and asked Joe at zpacks a few questions. Here is what he told me via email about the haul:

"2) I also tested a new pack that can handle up to 40 lbs on a recent 5 day trip.

These are the changes relative to a standard Arc Blast:

-Dyneema X Gridstop material to handle the load stress
-The belt is attached directly to the pack frame for the best load transfer. The belt is also removable / interchangeable.
-The shoulder straps and load lifter straps are also attached directly to the frame.
-The torso height can be adjusted up or down for a perfect fit.
-The belt and straps have 3D Mesh on the inside for more grip. The belt slides less.
-The belt is done with "V Style" webbing so that the top and bottom circumference can be adjusted independently. This helps wrap your hips more securely.

Those changes resulted in a 24 ounce 60L "Arc Haul" backpack. That is about 7 ounces heavier than normal. It will be $305. Or we could do a Zip version of it for $330."

Thanks, that's good news. Especially about the hip belt.

I absolutely love the Arc Blast but was considering an HMG before hearing of this.

I've been eyeballing something lighter for a winter pack as well, might be just what the doctor ordered :)

"@Tom: that seems like a project Zimmerbuilt or Jep Paks might be able to do. Even ZPacks or Oware might do it if you ask"

Thanks for the beta, John. I'll look into that.

Billy Ray: I find anything over 25lb in my Arc Blast to be unacceptable uncomfortable.

That is on the high side of what I have seen most folks say, I give your shoulders some serious credit!

For me, it has been in the 16-18 pound range when my shoulders start getting stressed.

Arc Haul

Here is what I can share about the Arc Haul… but it is almost identical to the message that Luke posted above…

But first, to address the issue… as I see it…

The Arc Frame has what I have been calling, a “floating frame”. Meaning that the frame is free floating from the shoulder straps and the hip belts.

Well, all that really does it make the body of the pack stiff, it does nothing to actually do ‘load distribution’. A free floating frame does not distribute weight, it just keeps the pack stiff, or in the case of the ‘arc’ it causes a bow in the body of the bag – to keep your back from not sweating.

Even some of the other companies out there that use straight aluminum stays, and even a few backpacks by big name cottage companies use the u-stays that fail to distribute weight properly.

Why? How?

Because the goal with stays (regardless of the type) is about getting load distribution from the shoulders down to the hips. We all know that the hips can carry a lot more weight than the shoulders, so that is the end goal, eh.

(obviously none of this is necessary for sul packs, or those young bucks that just enjoy lugging around 60 pound packs, manly studs and all)

IF the frame does not directly connect to the hip belt, it is what I call a free floating farm. In other words, its just out there floating around. What we want/need is a pack where the frame connects to the hip belt and the shoulder straps — the ‘harness system’.

If you take a look at, say the SMD Fusion, the entire harness is basically one solid piece. From shoulder straps to hip belt. This means that weight is distributed right now the spine of the harness system — just as the weight of your big head is distributed down your own spine to your feet.

So back to this “Arc Haul”…

As Luke quoted in his email with Joe:

The “The belt is attached directly to the pack frame for the best load transfer”

The “shoulder straps and load lifter straps are also attached directly to the frame”

Well, both of those statements by Joe means that the Arc Frame is no longer free floating frame.

I am not really sure about this statement, “Dyneema X Gridstop material to handle the load stress”… because if the frame is doing its job, there shouldn’t be any load stress on the fabric, beyond just the attachment points.

“belt and straps have 3D Mesh” — that is nice… it will give a bit of extra padding. I have long hoped ZPacks would make softer shoulder straps.

“The belt is done with “V Style” webbing” — ah, so following in the line of others. I like this. The SMD Fusion that I have been using has this style, makes for really nice dialing-in of the hip belt.

From the photos I have seen, I think this is a great set of first steps on the part of Joe/ZPacks to take their Arc Frame to the next stage. They have been good about addressing issues with the design. Early versions had buckles that were snapping so they went to round cordage. Given that they have a patent pending on the design, we have to presume they have not been able to manipulate/change too much about the design.

The hip belt changes that I have seen, seem to be a huge step forward in getting the Arc system to handle a better load. It changes it from a free floating frame to an attached frame. Time will tell if it actually does do load distribution. And attaching the shoulder straps to the frame (guessing along the top bar?) should make a top-heavy bag a bit more bearable on the shoulders.

Anyway, no insider info here… just sharing my own thoughts on this whole issue. I have already talked a bit about all of this in my “Gear of 2014” article, in which I had this to say about the ZIP:

ZPacks Arc ZIP:

Arc Zip Pros:

Caters to my love of front panel loaders – makes it super easy to load and get stuff out of. No more having to load a specific way just to get easy access to specific stuff (ie: heavy food normally we put at the top of our packs can now be down at the bottom of the pack, on your hips where the weight belongs, and you can get to it anytime without unpacking everything). Awesome fabric that has been able to handle all the abuse I can throw at it. Excellent side pockets, perhaps the best in the industry. Taped seams so it can handle hiking in the rain better than any pack I have.

Arc Zip Cons:

It hurts my shoulders at much over 16 pounds TPW. Hope to see ZPacks make comfortable shoulder straps one of these years. They are much too stiff, not wide enough, and are attached too narrow together for guys with big necks like myself and a lot of others. ZPacks also needs to redesign the way the (patent pending) Arc Frame works, because right now it does not properly attach itself to the hip belts in such a manner as to have proper weight distribution, a rather serious engineering flaw with the Arc Frame system. If they fixed/changed these two issues this pack/frame system could easily handle much greater loads and not cause so many hikers pain in the shoulders – it is not just me, I hear and read about this issue a lot.

Arc Zip Final Thoughts:

What can I say… I spent three years designing the lightest front panel loader backpack on the market, I am super proud of it. If you are a hiker that loves front panel loaders and can keep your TPW at under 15 pounds, the Arc Zip the THE backpack you should be buying. What Joe V and I were able to work together on and produce for other hikers really is amazing. Front Panel Loaders are going to make a comeback in the next five years and it will mostly likely be a result of the Arc Zip. Once hikers are able to start really getting it out onto the long distance trails and writing about it, hopefully things are just going to explode and a renewal of love for front panel loaders will be happening. ZPacks has already made a huge name for themselves with the Arc Frame design. By merging together my efforts of the front panel loader and Joe’s work on the Arc Frame, it really is a leap forward for front panel hikers. Simply put, if you like front panel loaders, go buy an Arc Zip.

Within the “Arc Zip Cons” paragraph I talked about just about everything ZPacks seems to be changing: a higher load weight and a proper load distribution design. I am sure that did not make them all that happy, but hey, it was the truth from my end of things. Whether my statements caused them to make changes or if it just added to the already growing group of folks here at BPL, at WB, and elsewhere, that have been saying the max-load weights where off by a good 10-15 pounds, regardless of any of that, it is nice to see a cottage company making changes to attempt to improve their gear.

(ps: sorry for going slightly off-topic from the OP… I just wanted to share my thoughts/insights on the latter discussion of the Arc design)

(ps: agree with others that say adding an extra two-three ounces for a proper frame is so worth it. why suffer and have to pop V-i at the end of the day, all because you were not willing to go with a backpack that would have weighed a few extra ounces, yet would have mean a pain-free day)

Very interesting stuff on the Arc Haul, can't wait to see what comes of it.

Thanks all for sharing. I'll be sticking to my SMD 65, until I can devote more time and money to a MYOG project. For lighter loads, I can just take the prophet :)

The use of a dual-buckle hip belt for the Arc Blast would, IMO, increase its weight-carrying limit enormously by permitting the hip belt to cup the iliac crest, which is no doubt the reason for its use in the rumored Arc Haul. I used to own a 75-liter(!) McHale and there is no doubt that the ability to 'cant' the top of the hip belt inward made it almost comfortable to carry too much weight.

As it is, when carrying 20 lbs or less the Arc Blast could actually get away with a narrower hip belt because I've noticed that – over time and with a fair amount of use – the top and bottom padded portions tend to flare out and end up not serving any function anyway.

I wouldn't be surprised in the least if all Arc packs end up with the 2-buckle set-up. Already I'm thinking of a retro-mod for my Arc Blast…

Yes it looks like pack designers are finally learning about dual pull hipbelts (ULA and McHale have for years) and better integrated stays with the harness and hipbelts. It is another reason I have thought the Kalais was well designed and carries well.

I love my Kalais for the same reasons +1 for what Alex said !

EH Kalais hip belt is magic, although I can only compare it to old style heavily padded REI backpacks. It occurred to me to try to attach this hip belt to an Arc Blast, but I figured I would still not have the load transfer I get with Kalais. I'll just carry the extra 14 oz and wait and see what Joe comes up with next.