Curving back panel of a pack: How much difference does it make?

My personal experience is that it’s helpful for the pack to hug my back as closely as possible in as many points as possible.  I want friction to help prevent the pack from slipping lower on my hips and hence shoulders when I “bounce” the pack (e.g., by stepping down a steep rocky slope).  Packs that can’t be formed to my particular curvature (e.g., most external frame packs, any pack with the horrid trampoline thing) create pressure points and require a tighter hip belt to prevent down-slipping.

If my hips were wider or my waist smaller, it would probably be different.  I’ve envied some of my female hiking buddies who have a natural “shelf” for the hip belt to sit atop without having to cinch the belt tight.  And I’ve pitied other buds whose man paunch forces the shoulder straps to do all the work.

Todd–We’re both on the same page about wanting a pack’s back to fit closely to our own back. My question is: for myog pack-making, do you think the pack bag needs to have this curve built in, or is the curve of the two stays enough to get the full effect we want? Any thoughts on that?

Hmm.  I guess the right answer is ‘I don’t know,’ but my suspicion is that unless the pack is so full that it’s tight like a balloon, it’ll follow the contour sufficiently.  But if you’ve dialed in the size/volume to exactly match your usual needs (i.e., it’s usually tight), maybe the customization will help.

Since you’ve already done it one way, you *could* create a second data point the other way and then tell us the answer!  :-)

Todd–I made the first pack with a zig-zag approximating a curve to fit my back (inspired by Paul McLaughlin here on BPL). I think I’ll do the same on the next pack. it’s not that hard really, and probably helps.

Doug,

Does a ‘zigzag’ side impact the ease of packing stuff into the pack?

I’ve not yet made a pack, but would like to one day- if I outlive my current one 🙃. I have altered them. Other than shaping the stays/framesheet, it been altering the waistband that makes the pack sit properly. But im curious about the zigzag/curved sides idea.

Megan

It won’t bring about major changes, but as a DIYer, it takes little effort to apply a curve. There have been a few articles on BPL by David Chenault, such as https://backpackinglight.com/load-carry-frameless-packs-chenault/. See also his own site https://bedrockandparadox.com/2015/06/24/a-dual-stay-light-pack/

I used this last article as the idea for my own backpacks.

https://photos.app.goo.gl/lxokfl6uoXAsGAa62
https://photos.app.goo.gl/uxcDNkvjRpaomNbB3

> I wonder what McHale Packs does

I recently tried a McHale demo pack. I told him that I wanted extra curvature in the stays so that they would fit the curve in my back, and he obliged. But I don’t think that the demo pack’s side panels were cut in a special way to accommodate a curved back.

Megan–I don’t think a curved back panel aids in packing, it’s just meant to help (along with curved stays) the pack fit to your back better.

Ivo–Those are some cool packs—shows you put a lot of thought into them. Yeah, a curve isn’t that hard to do in a myog pack, so I think I’ll keep doing them.

John–Thanks for the intel on the McHale pack. I really admire his packs, though I carry light loads and don’t want to lighten my wallet that much!

I have the SWD Long Haul. SWD shapes the stays to the curve of the back, both the newer tubular stays and the older flatter ones. I’m pretty thin, and I find shaping my pack to my back is one of the most important factors in my pack comfort. My loads feel lighter and the pack doesn’t rub my torso the wrong way. The curves in the SWD stays were already very similar to my back, so I only needed to shape them a little bit. My old GG Gorilla went from being a pretty comfortable pack to being an extremely comfortable pack once I shaped the stays to fit my back better.

I feel like it helps – a little. Mostly in the sense that with the stays bent to fit your back and the curve (or approximation of a curve by way of a mild zig-zag) following them, you don’t have the stays fighting a completely straight barrel. But, I’ve never built two pack that are otherwise identical except that one has the profile and one doesn’t, so I have not done research to substantiate my guy feeling. I started doing it because the best packs I saw on the market at the time all had some degree of contouring to them. When I load one of my packs, the shape is definitely influenced by the shape of the side panels. And I came up with the particular shape I use by approximating the shape of my back, so it is optimized for me. I started with a curved version, but that is trickier to sew (in the sense of aligning the pieces correctly) than the zig-zag approximation and I can’t feel any difference between the curved and zig-zag versions in use. As with most things on a pack, the lighter your load the less difference it will make.

Paul—Thanks for chiming in. I got the idea of the zig-zag approximation of the curved sides from one of your comments here a while ago and used it on my first pack. I started this thread out of thoroughness and laziness, thinking maybe I’d try straight-line sides the second time. You’ve convinced me to stick to the not-really-so-difficult zig-zags.

I always appreciate your input, drawing on all your experience making lightweight packs with good suspension.

My McHale has a very minor curve in the lumbar area otherwise rest of the pack is straight.

baja bob—Thanks, it’s always interesting to hear what the master of backpacks does. I suspect that minor curve is not per customer, but rather a standard shape for his packs.

Btw, I’m just curious, do you know which aspects are custom-fitted? Of course the torso length and hipbelt length. Anything else?