Sunday, August 9, 2009

Hawai'i Pack, Part 1

I'm planning a trip to Hawai'i come October, where I'll be doing some light backpacking & camping & stuff. And I need a big pack. So I'm making one.
It's going to be an internal-frame pack (the easiest frame to make--I can't bend aluminum tubing--that's too hard) and I just bent the stays, my pack's spine:
I've never made a pack like this (well...more on that later), with the double curvy stays, so I'm sure I'll have to tweak these a bit, but I think it's a good start.
I got these from, a pretty sweet metal shop. These are 1"x 0.1875" 6061-T6 flat bar aluminum. I guess the aluminum alloy that's the absolute business is 7075-T6, but they didn't have that in flat bar this thin, so this is what I got. Though, the 7075 is probably five times the cost of the 6061, and this is my first bent-stay pack, so 6061's fine for me. It's what most commercial packs use anyway.

My main source of inspiration is Dan McHale's packs. (See 'em here:
I've never seen one in the flesh, but from what I've read, if you want a badass custom alpine pack, go no further than McHale. Seriously, I can spend all day looking at his Website.

I've made a couple handfulls of backpacks in my day, but I've only made one framed backpack. That was for a trip to Spain I took back in 2006.
Here I am:

My friend and I walked a bit of the Camino in the north. I used a scandium alloy lacrosse shaft with two aluminum cross bars as a frame. It worked okay...but when I designed it, I was erroneously working under the belief that most of the pack's weight is carried on the hips. It's not. Most of it is carried on your ass shelf, on those meaty hunks on your rear (or at least that's what I believe now...we'll see in a year or so). So my pack's lumbar pad was added as an afterthought. And there was no curve in the stays to help distribute the weight back there. But it worked okay, like I said. But this time, things are different.
Oh, and this is the waist strap from my first pack. I'm not going to reuse it, but I thought I'd put it up here for reference.
1680d ballistic nylon + 1000 weight fleece. Those are 1.5" buckles. The staps in the back & sides attach it to the pack.

So here are my plans:
>Waist belt. I'm going to use the basic shape as the one above, but it'll be slimmer in the back. The lumbar pad will be integrated into the bag. In my first pack, I just had a piece of foam and plastic that I wedged in between the belt and pack. This was my lumbar pad, essentially. It was amazing how much it mattered though. That extra 3/4" of material transferred a lot of weight from my hips to my lower back area.
The trick here is how to connect the waist belt to the pack, though. It has to be flexible so it doesn't make the pack rock when you're walking, yet secure, in order to transfer the weight from the stays to the belt. Some packs do it with straps and Velcro. Some just with straps. Some bolt the stays to the belt. Some just sew the belt to the pack... I tried the straps-only method last time. It was flexible and it allowed me to remove the belt for air travel, but I don't think it distributed the weight to the best areas. And it tended to pull the belt away from my waist. Not so good.
I'm not yet sure what I'm going to do here. I'm thinking of a system with loops and an aluminum bar. The loops would alternate top to bottom and enmesh like teeth, and the bar would slide through them, holding them in place. Think about how the hinges on your door work. Like that.
I want to build the bag without the belt attached, otherwise it'll be way too hard to sew together. And having the option to remove the belt to use for something else, or just to remove, is nice too. Hopefully I'll knock this out fast enough to try it a bit first. When I went to Europe I finished my pack the day before...not so smart.

>Main compartment. This is going to be as simple as possible. Just a plain ol' sack. No sleeping bag compartment, no fanny pack lid. Just a tube with a roll top. I'm going to get some X-Pac fabric from Rockywoods ( for the main part, and I'm going to use 1000d Cordura for the bottom...probably double it up. The sides'll be fitted with compression straps, and there'll be removable side bags.

>Harness. I'm going to use the system I used for my last backpack (here), but with load-lifter straps, too. I don't know if I'm going to make them adjustable or fixed just yet. Probably fixed. I'll just have to make sure my measurements are spot on. Ha.

>Other stuff. There'll be a pocket for a water bladder on the inside. I'd like to put it on the outside for access, but I think it makes more sense on the inside, closer to my center of gravity.
And I'd like to put some small pockets on the hip belt, and maybe a chest pocket between the straps, for a camera...but we'll see.

Wish me luck.

To be continued...

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