I use carbon two vertical pieces of carbon tubing as the primary struts in my home made pack. Have had several years of use with no breakage. You can see my frame in the Make Your Own Section of this website under DJ's Frame Pack-updated.

I've had carbon fiber poles break in tent usage. When using them in my pack, however, they are only slightly bent and therefore less likely to break.

I also fill the ends of the tubing with a fiberglass rod and protect them with nylon plumbing tees. This prevents end splitting.

I've tested my pack by dropping it many times, on purpose. It has never broken. The steps I described above plus the flexible nature of my design see to protect it.

Two vertical struts, weighing about 1 ounce each, are more than adequate for supporting 40 lbs of weight.

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