9.5 Ounce External Frame Backpack

Posted by: DJ2

9.5 Ounce External Frame Backpack - 12/12/09 12:48 AM

This is a continuation of the thread entitled "Very Light Pack Frame".

Photos show the latest frame pack I just finished for my wife. The small sack hanging on the door knob is the disassembled pack in a tent pole stuff sack.


(1) Total weight of this pack is 9.5 ounces including frame, bag, padded shoulder straps and padded waist belt with 2" quick release buckle.
(2) Weight breaks down like this (in ounces) frame 2.2; bag 2.7; shoulder straps 1.2; waist belt 3.4 for a total of 9.5 ounces.
(3) Pack can be taken apart and carried in a stuff sack the size of a typical tent pole stuff sack. It can then be put back together quickly and easily. No tools required. My wife took an older model apart for her flight to Spain. She put it back together, hiked across Spain and then took it apart again for the flight home.
(4) Bag can be slid up and down frame with a single buckle adjustment. Picture shows it in lower position. Some people (e.g. I think Charles, our website host) would prefer it higher on the frame.
(5) Pack can be fit to any height person by replacing the two vertical carbon fiber pieces of the frame tubing with ones of the correct length for that person. This can be done in seconds.
(6) Bag capacity is about 3500 cubic inches. There's room to strap on a top bag for an additional 1500 cubic inches if needed (where you see blue foam in picture).
(7)Bag, shoulder straps and waist belt use 1.9 ounce uncoated ripstop nylon. I like uncoated so I can throw everything in the washer after a trip. I rely on an internal plastic sack for keeping things dry.
(8) I've used a pack similar to this one for about 30 lbs of weight. More weight could be carried by replacing the two pieces of vertical tubing with stiffer and stronger carbon fiber tubing. The additional weight of stronger/stiffer tubing is negligible.

Further Weight Reductions?
A couple more ounces could be shaved off by using cuben fiber fabric instead of the 1.9 ripstop. This would reduce the total weight to less than 1/2 pound. Does anyone know if cuben fiber fabric can be run through the clothes washer?

Another 2 ounces or so could be shaved with a few other ideas I have. They all result in less convenience, less strength or less durability, however. My friend Jenny says one could save weight by using their hat as a cereal bowl but is it worth it? I probably won't implement these last weight saving ideas so I'd say I'm pretty close to the point of diminishing returns on the weight reductions for this pack.

Weight Additions?
I've made several packs with larger bags. It is very tempting because you get a lot of volume for the additional fabric weight. The volume of this bag, for example, could be increased by 1000 cubic inches for less than 1/2 ounce of additional fabric weight.
Posted by: Keith

Re: 9.5 Ounce External Frame Backpack - 12/12/09 08:20 PM


So where did you get the carbon poles?
Posted by: DJ2

Re: 9.5 Ounce External Frame Backpack - 12/13/09 03:13 AM

Carbon fiber tubing can be obtained from archery shops, kite shops or Fibraplex (pole maker).

Here's one source I like: