Companion forum thread to:

Lightweight Frameless Backpacks State of the Market Report 2011
Part 2A - Technical Evaluation and Measurement of Pack Volume and Volume Reduction Capability

Edited by dtpaladino on 06/14/2011 18:39:14 MDT.

in light backback technology!

"in light backback technology!"

Or graph building.

It's a pity that adventure racing packs were excluded. In fact there are not so many places in internet about adventure racing (as i can see - nothing like BPL). But i think AR gear can be very effective (and for UL backpacking too), because it is tested in most rigourous conditions. It would be great to see BPL reviews.
p.s. And I wonder - which packs could be added in such case? Inov-8, terra-nova, what else?

I hope the Gossamer Gear Murmur is included in future installments.
That is the UL crown jewel of the GG line, in my opinion.

The SMD Traveler is intended to be used with a CCF pad stuffed in the back panel. I'm assuming the volume & compression ratio numbers above were determined/calculated without the pad. How much would the addition of a pad sway these numbers? If the pad were a standard 3/4 length Z-Lite (folded to 11"x20"x3"), it would suck up 660 cubic inches, putting the Travelers volume at 3505/2790/1850 (total/main/compressed), resulting in a compression ratio of 33.7%.

I suppose this line of thought can be applied to any of these packs as many intend for a pad to be used inside as support in some manner, but with the Travelers pad-dependent design, these extra numbers seem particularly relevant. Personally, if I end up with a Traveler (on my short list), I would rather not use a CCF pad, so I'm watching closely how well it fares in these tests.

Will, Janet, Roger, can't wait for the next installment.

The graph-making was Roger's contribution, according to Wills notes.

It would be nice to address UL packs that can handle a bear canister as well. Many packs are just bearly big enough (no pun intended) and turn into a cylinder when you drop the can in, which is not comfortable against the back.

Awesome.

Hi all, thanks for the comments and kudos. Roger helped me with Figures 2 and 3; we needed to trick MS Excel a bit to do it. Lots of graphs in Part 2B coming up.

Re the SMD Traveler pack, we decided to measure volume of all packs without a CCF pad so data are comparable. Thanks for the calculations of the volume that would be taken up by a CCF pad.

Happy hiking, Will

Will,
Whereas the Mountain Laurel Designs Exodus Pack volume was dramatically larger than stated by the manufacturer, did you happen to measure the Prophet pack's actual vs stated volume? I am curious if it too is significantly larger or if it is close to the stated volume?

Edited by taedawood on 08/21/2011 21:08:06 MDT.

Will,
You say "the Gorilla has two side compression straps plus a front bungie system, the Mariposa Plus has only a front bungie system."

You can also rearrange the bungie cord on either pack to give you side compression. That's how I have my mariposa rigged. I like having bungies on both sides much better than a single front bungie.

I don't know how much of a difference it would make in your measurements. For me it provides all the compression I need.

Great series of articles. Thanks!