Zpacks arc back mesh panels – Comfort

[Sam G]

I’m on day 3 of searching to see if anyone else has the same comfort issues with the new (or old i guess) Zpacks Arc blast/Haul style trampoline mesh back panels. I just picked up a new 2017 Arc Blast to test out and possibly replace my OHM 2.0. What I notice is a very distinct, annoying feeling of the taught edges of the trampoline back mesh panel rubbing and hitting on the lower bone of my scapula/shoulder blade.

Maybe mine stick out more than normal, but I am not a skinny bony dude (5’10, 195lb) and it just seems to really annoy me so far in my testing. I am use to my OHM 2.0 soft back panel right against my back so maybe just seems more pronounced.

Has anyone else experienced this with their arc style packs? Any recommendations? I have tried adjusting the panel up and down, but since it’s the otter taught webbing part that seems to hit it, it does not change it much.

Thanks guys and gals.

[JCH]

I am 6’1″, 220 lbs…not a small dude…and have not experienced what you are talking about.  Not every pack will work for every person.  Perhaps your body type/shape just doesn’t work with this pack?

I took your description to mean the sides or vertical edges of the trampoline were the problem.  Just a few thoughts:

• Have you tried relocating the entire trampoline up or down?  There is 2-3″ of vertical adjustment possible just by adjusting the tensioning cords.
• Have you tried different amounts of bow?  I found the pack very comfortable with almost zero bow (nearly flat) in the stays.  For me, the only benefit to the bow is the increased ventilation keeping the pack off my back

[John Q]

Sam,  I experienced the same discomfort from the Zpacks Arc style packs.  When Joe was still doing custom work, he tried to reconfigure the mesh panel to help alleviate the discomfort by using webbing instead of cord, but to no avail.  I ended up sending the pack back.  Joe did his best to help, as usual.  I’ve stayed with the original frameless Zpack blast packs and MLD frameless Cuben packs as my only “go to” packs with no discomfort issues.

[Sam G]

JCH, the issue is the edge of the trampoline, which is essentially in the same spot no matter where it is, higher or lower. It is definitely worse when it is tighter (More Arc) and when it’s nearly flat I dont feel nearly as much. It definitely is more about the width of the mesh panel just happens to ride right where my shoulder blade fits, so it’s probably rare. Just a bummer as the pack is no where near as comfortable because of it.

[Greg Mihalik]

^^^

I sent mine back for the same reason.

[Brian B]

Same issue 2013/2014. Tried to talk Joe into making a wider trampoline; he dissuaded me. Figured I’d just give it a go b/c it had so much other packs didn’t. Since then, I’ve used it maybe 200 days, still use it. Joe was right.

[JCH]

Sam, I was afraid of that :(  It’s a shame, it really is a great pack, if it fits that is. Hopefully you can return it. Best of luck on your search for the right pack.

[Sam G]

I guess I am glad I am not completely alone. I emailed zPacks and they said: “Once you get a couple of miles in with the pack, it becomes a non-issue” Not sure that’s possible since the taught edges won’t get less taught without losing arc, but maybe I would “get used” to it.

The issue is less noticible if the pack is looser on the shoulder straps and not tightened down. For example, if I engage the load lifters tight, it becomes extremely worse and digs in hard. If I let the pack sit on hips only with shoulder straps mildly snug, it’s just noticeable.

The pack is so nice otherwise, so it’s hard to just chalk up as a no go, but I’ll have to put a few miles on it to see first. I’m down to about a 9.5lb base with that pack, so debating a frameless pack as well. The OHM is still awesome,. But would like to cut some weight if possible.

[JCH]

If I let the pack sit on hips only with shoulder straps mildly snug, it’s just noticeable.

Everyone likes their pack adjusted differently, but this is EXACTLY how I adjust mine.  All weight is on the hips.  With the pack’s center of gravity directly over the small of my back, the shoulder straps are adjusted loosely and do nothing more than keep the pack from falling backwards.  IOW, the shoulder straps apply only light pressure on the front of my shoulders.  Adjusted thusly the back panel just lightly touches the back.  I’ve adjusted all of my packs this way for 15 years and have shown many others how to do it, each of them reporting a much better load carry.  The trick is learning how to load the pack so that the center of gravity is correct…place concentrated weight as close to the back of your neck as possible.

[Nick Smolinske]

I had the same issue with my MYOG packs (using the Zpacks arc blast design).

I’ve made two alternate styles of back panels that have worked well. I will post photos tonight. If I forget, please bug me! I’ve been meaning to post them for a while.

[Sam G]

JCH, I am with you on this as this pack does carry that way really well. I loaded a semi normal load in it and am amazed how well it transfers to the hips. I’m probably going to try the pack for that alone with just a slight arc. I really don’t think this issue would cause pain.

 

Nick, I’d love to see those pictures for sure. Like the AZ flag avatar as well. Native AZ here.

[Todd T]

Every trampoline pack I’ve ever tried on was a torture device.  If you ain’t shaped right, give it up and go to something else.

[Nick Smolinske]

Sam,

AZ is a pretty great place. I’m up in Flagstaff, been here about 8 years now. Here’s a photo of the alternate back pad I’ve been using for a while. Basically it adds 1/4″ of foam between the webbing that’s tensioning the back panel and my back:

I decided to write more details about it on a new thread in the MYOG forum, to avoid hijacking this one. There’s also another prototype back pad design in that thread here:

https://backpackinglight.com/forums/topic/alternate-back-pads-for-myog-arc-packs/

[Erica R]

JCH, I also adjust my Arc Blast so I carry the weight on my hips, maybe up to 10% on my shoulders. I find the Arc Blast quite a comfortable (and way light weight at about 1.5 lbs) pack to carry. The frame added a few years ago is great, as is the double adjust on the hip belt. No issue with the trampoline. I agree, the only benefit of the tramp is increased air flow. Pretty nice! I might try moving some weight up to beneath my neck as you recommend. However, I generally pack with the most used items on top without regard to density.

[JCH]

Todd, you said it man.  If it just doesn’t work for you, cut your losses move on :)

Nick, I love the minimalism.  But it seems like if the trampoline edges dig into your back, that the bare cordage would do the same.  I assume you found otherwise?  I wonder if padding the edges of the trampoline with foam might mitigate Sam’s issue?

Erica, Functionally it makes sense to pack items needed periodically during the day at the top of the pack, but I find it rarely results in the load being distributed properly.  I have managed to get my kit dialed such that often accessed items are either in the hip belt pockets, side pockets or back mesh pocket.  This lets me pack my food, water, chair…yes, I carry a Chair Zero :) …and any other heavy items at the top of my pack.  Light (puffy) items go at the bottom.  When carrying a bear can I like to strap it to the top, outside the pack body. The trick is to load the pack such that it is balanced on the small of your back when you stand normally (straight up).  I’ve seen so many people with packs loaded such that they must lean way forward to balance it…these are also the people that complain about sore shoulders.  This is a guaranteed recipe for a miserable hike.  The downside of this packing strategy is your pack is a bit top heavy…probably wouldn’t work well for scrambling, but is perfectly fine for hiking on trails.

Dialing in your packing strategy is really a DIY/experience kind of thing…everyone’s kit is so different, there really are no good rules for what goes where.  Simply saying “pack the heaviest items at shoulder level as close to your back/neck as you can” is the best explanation I have devised.  Showing someone, using their kit, is best.

[Nick Smolinske]

With the design above the cord doesn’t dig into my back, because the foam pad is at the only part of my back that was contacting the mesh (my shoulder blades). The rest of my back didn’t touch the mesh and doesn’t touch the cord either.

So it may not work for others with differently shaped bodies. I am rather skinny with protruding shoulder blades. I’ve only made one pack with this design for my girlfriend so that’s a sample size of just 2.

I did try padding the edges of my mesh panel and it helped a bit, but the full width foam pad was much, much better. Then again, I made my own mesh panel and I haven’t tried one of the actual Zpacks panels so there may be differences there.

If you do try to retrofit the current backpanel I would recommend adding a whole block of foam running across the panel and hanging off each end by half an inch. That should be just as comfortable as the one I’ve made, just with the mesh panel instead of cord behind it. When I did the foam on just the ends it would sit on my shoulder blades kind of weirdly and slip off to one direction or the other.

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