Oct 5, 2010 at 10:03 am #1264026
I saw someone at school with one of the backpacks with the air filled bubbles as padding in the straps and had a kind of aha moment.
So heres the concept:
A pack with inflatable straps and back panel made of heat seal-able fabric (ala bender's Kooka pads)
The straps would be constructed much the same as they are now, but rather than inserting foam padding you create a sealed air chamber with a valve allowing you to adjust the air pressure of the straps at any time and deflate them when not in use.
This same concept applies to the backpanel, just like making a pad sleeve but sealed for air with another valve. And now you have adjustable padding as well as an extension to a torso length sleeping pad.
And…it could even function as some extra flotation for packrafting!
Its kindof just an extension of what most people already do with inflatable pads but its still a cool idea!Oct 5, 2010 at 5:52 pm #1651810
@vickrhinesLocale: Central Texas
You are going to get a lot of "it-can't-be-dones" and "if it works it won't be as good as ….blah blah" on this idea. Ignore all that. Just do it anyway. Even if it is a complete flop, so what??? you will learn a lot.
You can usually get valve companies like Halkey-Roberts to send you a few samples for free. (Send me a PM. I have a few that are suitable for small volumes. You can have them for the cost of a stamped, self-addressed envelope.) Consider using vinyl bladders for test purposes because vinyl is easier to seal and glue than the many other options – and easier to get.Oct 5, 2010 at 5:55 pm #1651811
WHY NOT!?! DO IT!!Oct 5, 2010 at 7:14 pm #1651842
James D BuchMember
Who knows. Instead of an adjustable bed with a "sleep Number", you can have an adjustable backpack with a "Hiking Number" or something of that sort.Oct 5, 2010 at 7:47 pm #1651852
Put Helium in them and put a negative weight in your gear list spreadsheetOct 5, 2010 at 10:11 pm #1651884
as soon as i read the topic subject, i had an 'ah hah!' moment also! great idea! think i might try it myself one day!Oct 6, 2010 at 1:18 am #1651914
the idea of adjustable frame tension with air pressure is interesting. It might take a fair bit of air pressure to give it structure and that means pumps. pumps of course add weight. and beg for multiple uses, ie., inflatable strut tent, lighting fires, inflating pads etc.
Maybe light bladders inside cuban pack would work. I've been involved with inflatable kite design for years with kitesurfing and bladders/valves/etc do add some weight and they do fail from time to time. Just as an aside, condoms acually make great test/emergency bladders for pack straps etc.
Still some room for innovation in the cuban tent with air tube support area as well. Tents are probably a better application for air advantages actually. Still very hard to make it into the ultra-light realm this way since bladders and sleeves and valves weigh more than carbon poles with current tent designs but worth more experimentation since there are "offset" advantages. Not carrying poles is an advantage in some ways as are freestanding tents (no pegs, pitch anywhere, etc.) Perhaps a tent designed around an inflatable floor? Lots of possibilities popping into my head……Oct 6, 2010 at 4:15 am #1651932
I had been using a Thermarest Lite Seat as my back panel in my SMD Swift. While you can't adjust the length of it, you can obviously adjust the level of inflation. When there's pressure on an inflated object, such as being sandwiched between your back and the stuff in the pack, you don't need a huge amount of air in the chamber to keep it rigid. In fact, I preferred the Lite Seat to be slightly under-inflated so it wouldn't bulge into my back.
Good luck!Oct 6, 2010 at 4:47 pm #1652121
I think it's a neat idea. You'd likely be best off to focus your efforts on the inflatable back panel rather than the shoulder straps. The padding in shoulder straps weighs extremely little and I don't think there would be a weight or function improvement with inflatable ones besides flotation.
For the back panel, I would go pretty thick like 2-2.5" think so that it truly functions as a sleeping pad as well. The only downside of this is that you'd be moving the load further away from your back which would affect your center of gravity somewhat. Maybe there's a good compromise between performance as a pack and as a sleeping pad around the 1.5" thickness.
Typically the back panels of normal UL packs range from 10-13" wide and 25-35" tall. This is a bit of an usual shape for a sleeping pad. It would make a decent pad under your feet, but it wouldn't really suffice as your main sleeping pad. It would be extremely cool if you could figure out a way to make it larger (ie. torso sized) so that it could use it as your main sleeping pad. This would save weight, whereas using it under your feet would just add function but not really save weight.
This might be getting a bit crazy here…but one idea to make it larger is to have additional 1 or 2 inflatable sections (ie. wings) that somehow pull out of the side of the pack when you want to use it in sleeping pad mode. When hiking you'd just have the middle 11 x 25" compartment blown up, but then when you go to bed you could pull out the wings and inflate those (separate chambers) to get a pad 3x as wide…or 33×25". It would actually be easier to just have one large wing (~20" x 25") that pulls out of one side. To store the wing, it could just be rolled up to the edge of the back where as flap would fold over it and secure it with a few snaps.
On the negative side, sewing that would be pretty complex and a simple rucksack pack + torso sized sleeping pad would likely be lighter, less failure prone and good for times when you'd rather use a different sleeping pad. So it really depends on the value placed on the inflatable 'frame'.Oct 6, 2010 at 7:48 pm #1652186
Another option would be to have multiple air pockets within the backpanel to create a channel down the spine for airflow and more support for the lower back.
Kind of like the backpanel of the Absaroka or most "commercial" internal framed packs.
I originally posted this just as a concept and to see where the MYOG community would take it but the more I think about it the more I want to make a prototype.
My mom is teaching me to sew…so I might just add this to my que of projects. How easy is heat sealing? Bender talked about using a household iron at first for his pads but that it took some experimenting to get it right. Anyone else have experience here?
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