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View Full Version : New Pack Technology: Bouncing, Lighter, and the Same Weight!?!?



bigmontana
12-20-2006, 16:51
So my day job is in science (I'd rather be on the trail) which may be boring to a lot of you, but this new article in Nature (a scientific journal) is relative to Whiteblaze interests and possibly the future of backpacking.

Yes, this may seem completely crazy but "rubber banding" your load and allowing it to bounce up and down on the frame saves energy according to this new pack design. The design allows the load to stay in relatively the same position instead of travelling up and down with the body as you walk (due to tight hip/shoulder straps). The "suspended load" doesn't require constant acceleration from the hips and instead rides with the body.

From the journal: "The metabolic cost of walking with the load falls from 640W for the locked backpack to 600W... ...Although the reduction in metabolism is modest (6.2%) in terms of the total metabolic rate, it represents 23% of the extra metabolic power (176 W) that is required to walk with a 27-kg load rather than with an empty backpack. Walking with 27 kg in the suspended backpack is equivalent to walking with 21.7 kg in the locked backpack in terms of metabolic cost, so for a given metabolic rate the suspended backpack enables a substantially heavier load to be carried."

What does this mean? You could potentially reduce the "perceived weight" of your pack without getting rid of anything.:D

It will be interesting to see if they can make this design light/comfortable enough for our taste.

If you have access to this sort of thing (many of you won't):
http://www.nature.com/nature/journal/v444/n7122/full/4441023a.html

bigcranky
12-20-2006, 16:59
This sounds like those camera/binocular straps that use a large neoprene band. They allow the weight to 'bounce' (for lack of a better description). I've noticed a clear difference in the perceived weight of my binoculars using one of these straps, especially around my neck.

Interesting thought to apply it to a backpack. Hmmm.

bigmontana
12-20-2006, 17:03
It's like getting 1 "weightless" pound in every 5 pounds that you carry.

bigcranky
12-20-2006, 17:08
Okay, I just took a look at the article, and it's fascinating. I can see an immediate application with an external frame pack -- maybe something like the Luxury Lite? -- but any good garage tinkerer should be able to rig something like this from a basic frame pack and bag. There is an illustration that shows how they measured the forces applied, and it sure looks like a basic ex-frame with some pulleys and bungee cords.

Internal frame packs might take a little more effort, and this research doesn't apply much (if at all) to frameless packs. But I can sure see the applications for the military and others who have to carry very heavy loads.

Nice find, bigmontana.

bigcranky
12-20-2006, 17:14
Hey I just noticed we're posting from the same town, and probably getting 'net access to Nature through the same library. Where are you?

bigmontana
12-21-2006, 12:49
Wake Forest University :)

bigcranky
12-21-2006, 16:36
Ya, me too -- Go Deacs!