On being framed (backpacks for the woods, part 1)

Disclaimer: for those readers who are BPLers this is rather inside baseball; and for those who are not following the threads might be difficult due to members-only citations.

I’ve always loved backpacks.  Since well before age 10.  They do cool things, and have for me an aesthetic appeal.  I first seriously modified a rucksack back in high school, but didn’t attempt to build a pack from scratch until just over two years ago.  Since then, I’ve made close to a dozen.  That none of them currently exist is a testament to the complexities of pack design and construction, and to the dangerous restless-mind syndrome which MYOG (make ya own geah) engenders.  Once you make your own stuff you’re all but guaranteed to become more sensitive to flaws and problematic details, and thus doomed to go through many packs in the quest for more complete understanding.

This post will be the first in a series exploring what makes a pack work, well.  The subject: defining framed and frameless packs, and in the process examining the basics of pack load carrying.

My first ground-up MYOG pack.  It left a lot to be desired, but I carried ~30 pounds in it across the Bob Marshall in October.

Traditionally a framed pack was one with some sort of structure inside the pack which allowed the torso length to be maintained under load.  A frameless pack was one lacking structure of any kind, think of a basic bookbag.  There are many earlier examples (mountaineering packs such as the Jensen), but it’s useful to look at things being complicated in the current era by the Ray-way and Golite.  I’m not sure at what point the frameless packs in this evolutionary line began to want more support, but pretty soon a frameless pack began to act suspiciously like a framed one.

Torso length is at the center of how and why a backpack works.  Weight is any pack is carried on the hips, shoulders, or some mix of both.  With heavier loads especially, most folks prefer the ability to select and vary the percentage.  Being able to do so is dependent upon the torso length of the pack matching that of the user, and on that length being maintained under load.  Succeeding in this respect is a prerequisite for a good pack, something without which other attributes (like a strategically padded, well fitting harness) can only be marginally effective.

The complication between framed packs and frameless started with enclosed foam backpanels.  The pack above had no sleeve inside, I just rolled my ridgerest in the classic burrito fashion and stuffed everything inside.  There are numerous possible problems with this approach, but perhaps the most serious is that the connection between the foam (here working to do load transfer) and the harness components has much room for play.  You can see the sagging above the hip belt wings.  Things like this result in shrinking torso length, which as linked to above quickly destroys pack comfort.  And true to form, I only got away with that pack on the Bob Marshall trip because I had done plenty of training hikes and upper body and core conditioning prior.  Before 2009 was out I added a better hipbelt to try and compensate for torso sag.

The same pack, with a few modifications, at the Buffalo Fork TH in Wyoming, May 2010.

The all-encompassing solution to this is a full internal pad sleeve.  Golite figured this out a while ago, and their use of a thin (1/4″), dense foam mat in a snug sleeve is why the various generations of the Jam and Pinnacle have all been especially resistant to torso collapse.  Will Rietveld even found that the Pinnacle performed almost as well as the internally framed Exos 58 in a recent test.  I know from personal experience that the load capacity of the Jam can be substantially increased by modest beefing up of the pad, and see no reason why the Pinnacle couldn’t be similarly enhanced.

The virtue of the frameless approach here is that a mere foam pad tends to preserve a degree of flexibility and thus when worn agility which internal frame packs too often lack.  There is certainly such a thing as too much frame for certain occasions.

In the same article series Rietveld defines an internal frame as a pack having stays with a direct connection to the hipbelt.  I don’t really understand what that means.  Will excluded the Hornet 46 from his frameless test on those grounds (it has twin rods which go between the back panel and the main pack and connect at the bottom outside corner, as well as a hipbelt with no padding and virtually no structure), while Roger Caffin excluded the ULA Ohm (with a delrin rod which seems more substantial than the Hornet’s “frame”) from his internal frame pack test.  Are the Hornet 46 and Ohm framed packs, or frameless?  And do either of them carry as much weight as a pack like the Pinnacle?

The third and last version of the pack pictured throughout this post.  For reasons hinted at here and discussed in detail next post (read: hipbelt), this pack did not work very well.

For me, the interesting answer is not yes or no, but a recognition that there probably isn’t a categorical difference between frameless and internal framed packs anymore.  There are various approaches to matching degree of load bearing with size and intended function, and likely more variance in this respect within either camp than between them.  Which approach will prove most effective will have to do with the other factors beyond resistance to torso collapse, to be discussed next.

Advertisements

16 thoughts on “On being framed (backpacks for the woods, part 1)

  1. A timely post (and I await the next one with interest) as I was thinking of replacing my winter pack (Pinnacle) with something with a little more ‘beef’ to prevent ‘sag’. I did have my eye on a Quest but I’ll hold fire on the ‘add to basket’ button for now.

    1. Unless I’m very much mistaken, the pad sleeve on the Pinnacle is the same as the Jam, i.e. it ends right about the top of the shoulder straps. If it extended up to the load lifters, it’d be better still.

      My big pack has double layer foam 6″ wide along the backpanel all the way to the load lifters and full length for the bottom six inches. Very effective.

      1. Yep, the Pinnacle is the same, the pad ends at the shoulder straps. I did improve the carry of the Pinnacle slightly by replacing the stock pad with an OMM Platformat (which is 10mm thick foam with a ‘wire’ support molded into it which offers support but can be ‘molded’ into shape) from my Villain pack.

        Unfortunately I learned last winter that my Pinnacle is too short for me (I’m between sizes and went for a Medium) so I’m in the market for a new pack. Customise another Pinnacle or give the Quest a go? I’m still undecided.

  2. Some things I don’t really understand.

    One of them is the attempt to “save energy by reducing pack weight” by reducing the weight of the pack by a stupid EIGHT OUNCES by removing stays or a framesheet and a little back padding. All in the name of “8 ounces of pack weight means you can carry 8x125cal/oz=1,000 extra cals”. Whatever. There’s limits to sanity.

    Aarn figured the whole thing out a long time ago but nobody’s paying attention. They kept the frame (to prevent collapse) and preserved agility with a harness that adapts to changes in your torso shape. Go figure. I guess their packs are still too heavy for us gram weenies. It doesn’t help that they’re ugly.

    Those eight ounces allow you to carry 25 or 30 MORE pounds of weight and prevent torso collapse, which seriously taxes your upper body.

    If you want to “train” fine. But if you want to walk far with a big load…

    I don’t get it. Frameless packs are for people who don’t walk very far, which is OK too. Or who are really buffed up, like Dave et al. 😉

    The funny thing is that most of the cottage industry is built on this “frameless is better because it moves with you” delusion. Strange.

    1. I agree completely, that of all the rather myopic ways to save weight and gain ____ this one takes the cake. I also think that a non-stayed pack can carry decent loads (up to 35 pounds) with no drawbacks. I have a foam only framesheet for my big pack, and one with an alu stay laminated in the middle. I use the former almost all the time because under my normal loads the later feels too restrictive (this might be alleviated with better design, still working that out), and even with a packraft, cold weather gear and all the food for two (like this past weekend), my pack rarely exceeds 30 pounds by much.

  3. Very interesting topic! I’m eagerly waiting the next post. I don’t know if strict definition are really necessary? Generalizations are hard to do anyway… Backpacks are quite a subjective topic and instead of strict classification I’d accept detailed descriptions and very detailed user experiences.

    Ryan: I think you have a good point. But there are also some advantages with frameless packs (mostly being easier to make a well fitting one) and disadvantages with framed ones (mostly not fitting for everyone) but since last summer’s 25kg haul with Pinnacle I’m also looking for a lightweight, spacious rucksack that could perform well with heavy loads.

    Joe: Maybe you could beef up the Pinnacle with some sheet plastic (e.g. http://www.extremtextil.de/catalog/Accessories/Sheets:::23_77.html?XTCsid=049ef7a72f0ec9572e4e2e3d34abaa31)? I’ve been thinking about this for a while now…

  4. This past weekend you didn’t have ALL the food for two… I carried a loaf of bread, and some ramen. Just because you carried all the heavy stuff… 🙂

  5. I look forward to your further postings Dave. I tried a Mountain Laurel Burn on an aborted hiking trip recently. I ended up doing maybe 10-12 miles with it. I only had about 15 pounds but at the end of the day my back was tight and knotted in ways it wasn’t when I carried much heavier loads for much longer distances with my Absaroka pack. I was definately sore after hiking long days with the Absaroka but it was different. My whole body would be sore from putting in a long day but no one place. With the Burn I felt like weight was unevently distributed and soreness was concentrated more in specific areas of my lower back where the pack just didn’t fit quit right. I think the Burn might fit better with the compression system (I forgot to really tighten it up). I might try the Burn again but I’m moving towards internal frames for pretty much everything except very light weekends. I think Christmas for me will be a Gossamer Gear frame and materials to make a new pack.

    1. The first principle in the final post in this series will concern individual fit. Just like shoes, if it doesn’t work for you all bets are off.

      Will R spoke very well to the proper role of compression in his frameless packs series.

      They have a following, but looking at the MLD belts I have a hard time thinking they work very well (for reasons I’ll go into later this week). On the other hand, I’m intrigued by the Klymit inflatable frame they’re selling. Could be quite interesting.

      1. Funny you should mention the MLD hipbelt Dave. I much prefer the hipbelts on my last MYOG pack. Its wider and it doesn’t have that silly triangle padding. On both my older model Jam2 and on the MLD the triangle hipbelt just doesn’t work. It concentrates all the tension in a narrow area at the bottom. I might as well have a webbing hipbelt. The Burn is really just a stop-gap until I have time to make something better.

  6. Totally agree.
    I wasn’t that happy with frameless packs either.
    Weight is not everything.
    Sure, if some one’s weight for a 3 day trip is under 15 pounds they are pretty good. But they never worked with a heavier load for me.

    As Ryan said: those 8oz (or more) allow you to carry more and carry everything more comfortably.

    Good point on Aarn. I just have a Aarn Featherlight Freedom and won’t go back to any other pack.
    I disagree that they are ugly. The frontpockets do not look too stupid and they really work, Furthermore I have everything that I need in front of me.
    I even don’t remove my pack on short breaks. The harness works. It is one pack that does everything for me.
    I mean does it really “hurt” to carry 3 more pounds on a short trip and be able to carry enough for a 10 day trip without a sore back and shoulders?

  7. I have to say that I love the topic of this post. I fit packs for almost seven years in Alaska at a small shop. I have gone through countless packs of all shapes, sizes, design philosophies and intended purposes. More than once I had the somewhat anxious pleasure of running into someone in the backcountry wearing a pack I had fit for them within a week of purchase. These experiences have forced me to think a lot about packs in general. I’m super psyched to see where this goes.

    p.s.- The Jam was one of my favourite packs (although I think I got a little bit overly-sentimental after I summited Denali with it on).

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s