The ultimate cuben pack? A HMG/Zpacks combo?

[Yoyo]

I own both the HMG 3400 Southwest pack and a 52 L Arc Blast.  The HMG has been my go-to pack, despite the fact that it weighs about 11 oz more than my Arc Blast.  While others may demur, I’m not a huge fan of the trampoline design on the Arc Blast, which places the pack away from one’s center of gravity.  For some reason or other, the HMG Southwest just fits me right.  This leads to a thought: Is there any way to have a pack built (without having to go the MYOG route) along the lines of the HMG, but with lighter materials?  The goal would be to have a pack in the 50-55 volume range with a frame that weighs around 20 oz or less.  I like the aluminum stays that HMG uses because they can be bent to fit the shape of your back.  With the Arc Blast design, there is wasted space behind one’s back (albeit providing cooling).  I haven’t carried super heavy loads with the HMG, but I feel like the two aluminum stays are adequate to carry a decent amount of weight.  I wouldn’t want to be carrying super heavy loads with the Arc Blast with the weight that far away from my back.

Thoughts?  I’m not really partial to either manufacturer although I will say that I feel that most of my gear is from ZPacks.  (They seem to make the lightest gear that I can find, and I like the customizability that has always been a part of Joe’s business model).  I am in love with my Southwest Pack, though…

[William Chilton]

“I feel that most of my gear is from ZPacks.  (They seem to make the lightest gear that I can find, and I like the customizability that has always been a part of Joe’s business model). ”

Oh, those were the days…

[Yoyo]

@William

Is the implicature from your post that this is no longer the case?

[Paul S.]

Can the Arc frame be configured to transfer weight to the hips without adding an arch to the stays?  That woils seem to address your only complaint.

[Yoyo]

I suppose I should ask Joe that directly, although he seemed to indicate to me that people have used the Arc Blast without the “arc” (i.e., run the stays without tension).  I haven’t tried this out…Has anyone else?

[Bob Moulder]

I’ve seen people who don’t tension the stays and it seems to work fine.

I prefer a lot of arc in them (approx 2.5-3 inches at the middle of the curve) because once I actually put the pack on the gap is greatly reduced anyway, so the CG with UL loads isn’t drastically affected.

Zpacks has abandoned the customization options of the past, for better or for worse. Seems to have sped up production considerably and they still have a fair number of pack options. Not like ye dayes of olde, however.

[Matthew / BPL]

David, I think people have noted that ZPacks has been trending away from customizable. It’s anecdotal but I tried to get them to make me a hybrid Zero XS last fall and they responded that they only make the XS in cuben.

The flip side of this is their lead times have shrunk. I purchased a Duplex in March of 2015 and it took about 6 weeks iirc. Today their site says they ship the same in tent 1 week.

[Thomas Willard]

The few people I’ve seen on YouTube or Facebook who did not put an arc in the pack discovered the top connection point of the stay would pop out due to not being tensioned.

[Alex Wallace]

Check out Superior Wilderness Designs. Their Long Haul UL50 & Superior 50 are very similar to a HMG 3400 Southwest especially with regard to the suspension & harness setup, but use lighter fabrics to drop the weight a bit.

Furthermore, they appear open to pretty much any modification. “We can build virtually anything you would like out of an ultralight backpack and we have a wide range of materials to choose from.”

 

[Luke F]

As surely as water runs down hill and heat moves from a warm body to a cold one, companies move from more custom options to fewer as they grow. It is always painful, and a little disappointing but practically immutable. In my observations the true custom shops (McHale, Zimmerbuilt perhaps, and a few others) aren’t all that interested in growing in the traditional business sense, and that’s what allows them to stay custom.

[J R]

I have the Arc Blast and prefer the curve but have worn it with the stays straight, it carries fine and never had a stay pop out. Personally I don’t buy into the center of gravity argument that a lot of people bring up about packs with a trampoline back. Yes, there is a gap that means that some of your load is slightly away from your back, but in the case of the Arc Blast the whole pack is relatively more slender and tall compared to many packs that have their own center of gravity issues by being more short and squat. And by being relatively taller, the Arc can carry some of your weight higher up, which will be directly over your hips and legs as you naturally bend forward slightly.

But that’s not what you asked. If you want to Frankenstein the best features of the two packs into one then I think you’re looking at the MYOG route or a shop that handles custom cuben work like McHale, Zimmer, etc.

[William Chilton]

“Is the implicature from your post that this is no longer the case?”

Indeed, as bobmny has indicated.

To add to some above, I also have used the Arc Blast without the curve and have had no problems with it. I don’t really see why the stays should pop out since they’ll still have force on them.

 

[Yoyo]

@William

Did you find it comfortable wearing it this way?  The advantage of the Al stays on the HMG pack is that they are prebent to fit your back.  With the Arc Blast (un-arced), it seems that the center horizontal bar might press against one’s back in an uncomfortable fashion.  I’ll have to give it a try, though.

[Bob Moulder]

A systematic approach would be to gradually increase the arc until the crossbar no longer touches the back, which would ensure comfort and also minimal GC shift.

[J R]

When I’ve worn it with the stays straight, honestly it’s because either I forgot to re-tension the arc at the start of a trip and wore it the first day that way or else I’m carrying a bear can and pushed it below the horizontal crossbar, which adds a lot of extra tension trying to pull the arc more straight, and sometimes does.

When worn that way I don’t feel the horizontal crossbar, more likely to feel the vertical bars against the length of my upper back and shoulder blades. And not “pressing” against me — with a light load that’s transferring most of the weight to the hip belt the pack is only lightly touching my back.

It’s not the most comfortable way to wear the pack but it’s not uncomfortable.

[Yoyo]

Is there then any structural advantage to the arc, do you think, other than keeping your back cool?  Do you think that having the pack tensioned with the arc contributes in any way to its load-bearing capacity?

Regarding customization, I received the following message from Joe today:

“We are not able to do custom design work for one off projects anymore.”

This is a little disappointing, as customization was one of the main reasons why I have chosen ZPacks in the past.  However, I will still continue to support ZPacks as they still seem to be committed to making the lightest functional gear possible.  I just wish they would still offer custom features, albeit at higher cost.

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