Hello Dan, thanks for the detailed and informative reply. Don't worry, I'm not really disputing whether stays should be used or not because of their weight. I'm merely trying to understand how they work... it just isn't completely intuitive when I look at it carefully. But your explanations make it easy to understand. Thanks.

I have bought in a sale a TNF pivotal Catalyst 75L +15L backpack, which weight in at 3kg.
(the idea at the time would be me carrying the gear for 2). Long story short, this idea was stupid.

Before you kick me out, please have a look at the suspension system which include crossed stays with a pivot at waist level.

The outcome is a pack which stays level while the hips can move in a much more natural way.
The belt is heavy and heavy-duty. Cinched tight, the combination of stays, belt and compression straps allow for a very confortable carry.

For optimal fit, the pack exist in 3 sizes and is also ajustable, hence the complexity and weight (although for optimal transfer, the precise adjustment to back-lemght may be mandatory).


All in all, I believe that acceptable pack weight is somewhat linked to the weigth to be carried. IMHO, a pack should be less than 10% of the weight to be carried.

stays or frame aren't necessary for less than 8kg
are required above 12kg,
and absolutly mandatory for more than 20kg.

My G4 experiences match what this thread describes. The only real difference is that you have articles, and experiments, and science whereas I only had sore shoulders!

Seriously though, the G4 is so big you can not cram enough stuff in there to make it rigid an still have anything resembling a lightweight pack. I would stick in a rolled up blue ccf pad, load my gear, strap on the G4, buckle the hip belt, and start walking. Sure enough, within 5 or 10 minutes the contents would settle, or the rolled pad would crumple, just enough so that pack's weight settled onto my shoulders.

David,

I am glad to hear that I am not alone. I can make the zpacks Blast 32 work great, but I had exactly the same problem you describe with the G4.

I like the 10% rule that the pack should not weigh more than 10% of the total load.

I also had the same experience with the G4, but I attributed the pack's collapse somewhat to its large size but mostly to the method of packing as recommended by GG. That method was to place the sleeping bag loose in the bottom of the pack and then load the rest of the gear on top of that. Since my bag is down, you guessed it, it would compress after a short time allowing the rest of the gear to settle and shift. Stays definitely would have been helpful for this pack!

Then I could never carry more than 52 ounces total in my Z1...It works fine with more.

>I like the 10% rule that the pack should not weigh more than 10% of the total load.

I think that means you shouldn't carry less than 52 oz in the Z1. Surely you're not going around with just over 3 lbs? :)

Devin,

Actually Matt might mean less than 52 oz.

Check this gear list for AT yo-yo hiker Brian Doble:

http://broble.wordpress.com/the-gear/

Wow!
-Mark

Edited by markhurd on 04/02/2009 21:57:48 MDT.

In reply to
"Then I could never carry more than 52 ounces total in my Z1...It works fine with more."

You have mis-understood my sentence.
" IMHO, a pack should be less than 10% of the weight to be carried."
does not mean that total weight should be at most 10 times the weight of the pack.

It just means than whenever the pack weight is more than 10% of the total load, you could most probably trade in for a lighter pack.

Why ?
because, after trying out many packs ranging from 280 gr to 3kg, for carrying between 2kg and 35 kg,
for ME and MY practices,
there is a correlation between the weight of a well-designed pack and its ability to carry.

I am quite happy with my quiver of :
- black diamond RPM 26 up to 6-8 kg .68 kg
- Deuter Aircontact 35+10 up to 15 kg 1.7 kg
- The North Face Snow Leopard 70l up to 25kg 2.3kg
- The North Face Catalyst Pivotal 75l did not go beyond 25kg 3kg

So I first choose what I need to transport (weight and volume) and then choose a pack. If the pack is more than 10% of my load , I look to the next size down.

YET It is true though that a similar rule could also work upward, because a pack frame, hipbelt, shoulder straps are ideally designed for a range of carrying capacity.

So Ok, I'll bite
IMHO, with today's innovations, with a goal of full-day walk in varied terrain over many days (my definition of comfort), a pack should be NOT less than 5% of the weight to be carried.

Have a look at http://www.backpackinglight.com/cgi-bin/backpackinglight/heavyloads.html second table.

All light packs for heavy loads in the article have a ratio Load/weight ranging from 10 (Lightwave Wildtrek 60) to 19 (ULA Catalyst).

Meaning, it is today possible to find packs for which
packs weighs are between 5 and 10% of the load.

Hence my rule... ;-)

>IMHO, with today's innovations, with a goal of full-day walk in varied terrain over many days (my definition of comfort), a pack should be NOT less than 5% of the weight to be carried.


I suggest you take a look at Zpacks Blast series. The largest pack weights 4.3 ounces / 123 grams. I am sure with 5kgs it is good enough for 20mile days. That puts pack's weight at 2.46% of the load.

Dont be hasty about forming rules. You never know if sub 1pound internal frame pack with ability to carry 40+ pounds comfortably may be just around the corner.

Sounds like you are introducing something new for all of us! Can't wait. :>) What corner is that? HaHa. Yes, you never know.

Edited by wildlife on 04/03/2009 14:31:51 MDT.