Framed (North Fork pack update)

Over the six months since I posted it my North Fork pack video has been quietly creeping along, steadily accumulating views, and quickly becoming my most viewed video that hasn’t been posted on Jill’s blog.

It’s been on day and overnight trips aplenty this winter: skiing, snowshoeing, packrafting and combinations.  It carries very well.  But all of those trips have been with fairly light loads.  Winter insulation and even packrafting gear is not especially dense, and even in winter you rarely have to carry much water around here.  That changed this past weekend; I had a moderate amount of insulation, almost all our food, snowshoes, and 5+ liters of water.  The heavy, dense, and smaller load challenged my normal carry system, where I fold my ridgerest against the back panel and place everything else in after, dense and heavy stuff in the middle.  Part of the problem was that I didn’t bother to reattach the bottom compression strap, which let the pack get too fat, but the main issue was inadequate structure allowing the torso length to collapse too much.  Shorter torso length equals more weight forced on the shoulders, which typically is not so comfortable.  I found it lacking.

Research has shown that only a minimal level of torso length collapse is acceptable, and that the amount of structure in a pack to fight against collapse needs to be proportional to the weight carried.  I’d add, based on experience, that ideally structure and weight would be closely matched.  Excessive structure for the weight results in a pack which is just as uncomfortable as the inverse, merely for different reasons.

With that in mind, before our Craters trip was over I set about designing modular improvements to the North Fork pack which would potentially allow me to carry some fairly heavy loads.  After all, its straps and belt are quite substantial.

I bought a 3mm by 30mm aluminum stay at the hardware store, cut it to length, rounded the edges, and sewed quadruple layer ballistics nylon pockets for each end.  I laminated those pockets to the blue foam, inserted the stay, then laminated the whole thing together with contact cement (nasty stuff).

I then sewed this double-Y strap into the interior of the pack.  While this is made to the dimensions of the framed pad (11″ by 23″), I can also use it to immobilize lesser foam pads when I need less pack structure, or potentially not use it at all (the black webbing is removable).  Basement tests with a good load suggest this will work well, but field testing is required to know for sure.

As can be obliquely seen in the video, I started with cinch straps connecting the dark gray side patch with the hip belt.  Unfortunately, poor design visualization resulted in the strap sitting in the hip belt cut out, which mitigated effectiveness and rubbed my hip bone.  It also wasn’t the secure yet dynamic design I’ve come to prefer.  So I fixed it.

Work arounds of this type, when the pack is already made, are quiet difficult.  If for no other reason than that fitting the desired area into the sewing machine is rarely easy, or especially doable with only two hands.  I’m glad I found a non-compromise way to do this that was at all feasible.

In short, we’ll see how these new designs work out.

In terms of the original design, I’m very pleased with how it has worked out.  The suspension components are excellent, the fabric continues to fulfill its promise (though it isn’t massively abrasion resistant, I have a few interior cuts from forcing packraft paddle shafts into an already tightly loaded pack), and the back and side pocket system has proved superlatively useful.

In short, I’m quite pleased with myself.  Using gear you designed and made is rewarding.

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One thought on “Framed (North Fork pack update)

  1. Update: the new waist belt – wing attachment is perfect. The frame is very good as well, solid weight transfer, but still good flexibility. The straps for holding the pad need to be cranked down pretty hard to keep the corners from slipping around, but works fine.

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