Well, this is "modify your own gear". A while ago I posted about some awesome backpacks we got cheaply. I've been using one of those packs ever since, and I've found one really annoying "flaw".
Here's the backpack. I've been using the one on the right.
The "flaw" is those two pipes that stick up above my shoulders. I usually use the pack my strapping 3 bags to it, each between one set of horizantal bars. My sleepingbag in a stuffsack on the bottom, my ursack full of food in the middle, and a drysack with my gear in it on the top (sometimes those to are swapped). I also have 2 water-bottle holders lashed on, and I often tie my hatchet to the frame or clip on a knife.
Anyway, I never use those two pipes, and when bushwhacking in heavy brush, they catch on low branches constantly, and keep me from ducking fallen logs.
Well The pack on the left has bars going across between those posts (see above) - these bars hit my head, and at least vaguely annoy almost anyone who uses the pack. The pack on the left is also quite common, the one on the right is rare (I believe older, and made for a shorter period of time). So, I figured why not remove the top from the annoying pack entirely, and save the rarer pack that's more comfy for use by others. So, I moved the sack back onto the frame on the right (where it came from originally), and also swapped all of the other pieces as well, since I liked the padding and such on the frame I'd been using. In particular it has padding on the lower cloth panel, this padding keeps the panel from bunching and makes it far more comfortable.
I then hacksawed the top segment off the pack with the cross-bars on the top. I pulled the caps off and stuck them into the stubs I'd left level with the wields (to avoid weakening the pack). And... voila! an awesome pack that won't catch on trees anymore!
The weight of the pack is 1.41 kg. as pictured above, that's including all the straps I use to attach sacks to it, and my "external pocket", but not including the leather hip-belt pocket or the dry sack that I put my gear in. the red dry sack is 97G. So the pack comes out to ~1.5 kg or ~3.3 lbs. Note that I'm still using the steel buckle, for example, which is anything but light.
I would not call this a completely unmitigated success, but I do really like the back. I've now used this on a couple of short trips, as well as one longer trip with a lot more weight (up in Yosemite) recently.
- Easy to carry extra gear (like an extra bear-canister), adjusts to varying loads well.
- Very good balance (holds gear close to back) and weight distribution
- Still low/small enough for bushwhacking
- Lighter than anything else with full-frame support
- Can hack it to be whatever you like, add pockets, gear, etc.
- Cheap ($2.50 plus straps)
- Simple, easy to hack, easy to build, easy to replace, easy to repair
- Easier to see what you are carrying
- Anything you want can be easy to get to
- It's cool! (literally, good ventilation)
- Takes longer to pack in the morning than an internal
- Getting to something from the "bottom" of the gear-sack is slow
- Heavier than ultralight semi-frameless internal options
- No sack to take the brunt of blows (I tore the drysack, despite it being tough)
- Gear can fall off (unless you're good with knots/straps/etc.)
- More lumpy/ungainly (so harder for lowering down cliffs, caving, etc.)
- Easier to see what you are carrying
I've now used it bushwhacking (old frame, before I took the bars off the top), except those bars it worked really well. The only problem I ran into was that I tore the drysack (which was on the top at the time) catching it on a tree-branch. Note that this was bushwhacking down a 45 degree drainage through dense manzanita and live oak (I.E. unless your crazy, you won't do this).
I've also carried upwards of 50 lbs in the pack (Jess hurt her leg, so I was carrying all the food, 2 bear canisters full). The original hipbelt, which I'm still using, caused some problems. The latch slipped with that much weight (though a hair-tie helped hold it), and the belt cut into my hip enough to start putting my legs to sleep. Not too badly, but I wouldn't plan to use the pack with that much weight, without a new hipbelt. I'll probably pick up a better hipbelt at some point (you can ask REI to order you a belt for one of their standard packs, I did this once to get a women's belt for Jess, for her old external).
When carrying that much weight, it would've been nice to have the 2 verticals still there, so I could put the second bear-canister up there (rather than slung on the back). That would've let me stand more upright - but that's not my usual usage, so I'm okay with leaning over a bit in the extreme case.
It's not perfect, but it works well. This is definitely an option to keep in mind if you want to go light, but have back problems. The frame is extremely comfortable, the straps are all replaceable, so if they aren't comfy you're not doing it right. It's not for everyone or every situation - but it it's another option that is surprisingly unexplored.