http://www.zpacks.com/backpacks/arc_blast.shtml

seems to me that mesh would last about a week..

Weight away from the centre of the back would not be ideal.

I agree with the previous comment about that mesh's apparent durability. Also, is it just me or does it look unnecessary? It looks like it could be tensioning the carbon fiber stays, but you wouldn't need the mesh for that, just nylon straps.

The external frame pack I used back in the Boy Scouts had a mesh panel that didn't have any durability problems.

Looks like the frame on the Osprey Exos packs to me. I kinda like the looks of this pack myself but I do worry about the weight being pushed away from the back as well.

It will be interesting to hear about how this performs .... I have a new exos I haven't gotten to take on a full trip with yet, but it seems to have enough space to be off the back when I have tested it out. Joe said keeping it off the back is key ..... which I think happens naturally for me with most packs I wear because of how I wear them. .... little bit of space between pack / back ... tiny bit loose on shoulder straps .....

My concern with the Arctic would be, as other have mentioned, displacing weight. I'm not a fan of Osprey's for this very reason (Atmos, etc.), the displacement off back bugs me .... don't mind on their day packs (love my Manta 30), but on a bigger pack the displacement doesn't feel right to me ....

Will have to give this a shot at some point after I'm more familiar with the Exos and how it performs ....

Edited by tracedef on 06/17/2012 18:26:01 MDT.

The weight is pushed away from your back in any traditional externally framed pack. The same thing happens for the most part when people use their pads as frame sheets.

WOW! Great pack!

The weight pushed back is OK.
The mesh is OK, you need it for keeping your pack pushed back (trampoline design like in all other packs).

This should be great pack for desert hiking! Trampoline pack weighs only 383 grams! OMG!
I should try it. A little expensive for me. My wife will not approve this purchase :(

Looks the poo to me.

I have an osprey exos 46 and love the vented back panel. Never feels like the load is too far back. When you wear the pack the distance isn't that great as the mesh conforms to your back shape a little and the pack sits that little bit closer.

I think this design is a great move and I can see one being my next purchase.

I've just moved to a Jam2 pack and the difference from the exos 46 is very noticable in the vented back panel. The vented packs just let your back stay that little less wet and cooler in the heat.

Yea I would be happy to beta test one but definitely wouldn't buy the few first runs he makes. id wait a few months till he starts fixing all the kinks people find and return to him..

As someone who suffers from a sweaty back I thingk the design looks great!
I guess how heavy your pack is will make the difference of whether it pushes the weight too far back.
I cant see the mesh having a durability issue as it works on pockets for lots of packs and they are exposed to snagging and wear most of the time, this is nicly protected from snagging by your back!

Just looking at the pictures, I see potential pressure points where those stays attach to the hipbelt. Having the stays fixed at the very bottom of the hipbelt, combined with the arc of them, might mean that the 3/8" foam will be inadequate in protecting ones lower back when pushing the weight limits of the pack...I am very interested to hear field reports!

The Arc Blast has the same construction as our Exo backpack, except that the body has a slight arch to it to match the frame. There shouldn't be any new issues with the pack itself.

The mesh panel rides in the small of your back and does not get much rubbing against it. In our testing we didn't notice any wear. The mesh panel also comes off easily via ladder lock buckles, and would be easy to replace. All ZPacks gear has a 1 year warranty plus free repairs for the reasonable lifespan of the product.

Is it possible to get one of these with twin hip belt buckles, parallel one on top of the other? And maybe a slightly beefier hip belt padding? And while I'm at it, get a higher amount of reinforcing of the cuben in key stress areas (frame attachment, shoulder strap, hipbelt attachment) points, like with some extra layers of regular cuben glued to the inside?

I can see this being an amazing pack, I'd just be keen to get a bit more weight carrying capacity out of it, like up closer to 20kg for longer unsupported walks/water carries.

I don't think the centre of gravity will be too much of an issue once its loaded and you have it on. Just make sure you keep the heavy stuff close to your back, and relatively high.

I've had two external frame packs and one internal frame pack with a mesh panel in the back. I've never had any trouble with the mesh wearing out in any of them. One of the external frame packs lasted over 20 yrs - zippers blew out, strap and waist belt attachments blew out, but no problems with the mesh. The mesh looked worn, but was still functional. It's nice not to have the pack rest right on your back!

Interested to hear field reports.

I just got a zero (with options that make it basically a blast), but have found myself going back and forth between an exos 58. All my other gear combined weighs about 6 pounds, but my 2.5pound Osprey generally feels more comfortable carrying it than my 11oz zpack.

"I don't think the centre of gravity will be too much of an issue once its loaded and you have it on."

You are right.

Just like the talk of the Exos (which is NOT the same as the Atmos) is false, there is no further weight/center-of-gravity issues than any pack with a solid foam back-panel.

Measure it before you call BS please. I did years ago.

Looking at the pictures, is it possible to double up the stays to give extra strength and beef to it? They look like they are easily removable/replaceable, with maybe enough room in the end stay pockets to add a second stay?

Drooling over this...wish I hadn't just spent all my money on camera gear.

Should be here in the next couple of weeks :)

I had an Exo on order, and Joe contacted me re. the Arc. After some correspondence I decided it would likely be a better fit. Just got my tracking number so it should be here Thursday!