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How Packs Work
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Maia
(maia) - MLife

Locale: Rocky Mountains
How Packs Work on 12/04/2012 13:05:33 MST Print View

Companion forum thread to:

How Packs Work

Travis Leanna
(T.L.) - MLife

Locale: Wisconsin
Nice work on 12/04/2012 13:18:55 MST Print View

Good write-up, David! This would be a good read for people, especially beginners, to get them thinking about how a pack really works, besides simply holding stuff.

I agree that getting a pack to properly accommodate your torso length is fantastically important, which is why I really like my Osprey Talon 44. As you know, it has the adjustable torso length and lets me perfectly fit it to my own body.

My dad proclaims he wants to do a week-long trip somewhere akin to Glacier. I may show him this article.



P.S. This article, along with a few others, should also be stapled to every employee's green vest at REI.

Edited by T.L. on 12/04/2012 13:20:22 MST.

Dan Durston
(dandydan) - M

Locale: Cascadia
Jam on 12/04/2012 18:18:29 MST Print View

"the Jam 50 went from 99 dollars at the start of the year to 129 as of this writing."

Stochastic indeed. It's at 132 now.

Edited by dandydan on 12/04/2012 18:22:32 MST.

Paul McLaughlin
(paul) - MLife
Re: How Packs Work on 12/04/2012 20:03:35 MST Print View

Dave, nice article. However, I Think your statements about load lifters not being needed if the pack is sized properly require some caveats. Let us travel back in time to the days of the external frame's dominance for a minute. Your typical 1970's external frame pack had no load lifters. But typical fitting protocol was to have the pack fit so that the crossbar to which the shoulder straps attached was slightly above the top of the shoulders. This allowed the shoulder strap to run upward off the top of the shoulder, so that the line of tension would be pretty close to (although a little lower angle than) what you get with a lifter strap if you tighten the lifter and loosen the shoulder strap. This angle is critical. To be able to achieve this with an internal frame pack requires a very direct connection between the tops of the shoulder straps and the stays, and stout stays. It could possibly be done with a particularly rigid framesheet, but again it would require a very direct connection of the shoulder straps to the framesheet. And even then it would still be at a lower angle coming off the top of the shoulder than a lifter (if the pack is properly sized and adjusted) will achieve, tending to put more wight on the shoulders, and also it lacks the secondary function of the lifters, that of pulling he top of the pack forward.

The other point - and I think you state this, but it ought to be emphasized even more - is that lifters can only do what they are intended to do if they are connected directly to the frame. On the packs I make, they attach directly to the top of the stays.

I don't know if you have ever had your hands on one of Dan McHale's packs that have his Bypass Suspension system. If not, I suggest to do, or at least study up on it on his website. Dan understands suspension design better than any other manufacturer, in my opinion - an opinion based on over 35 years of making my own packs and several years of selling packs on the retail level. His understanding of how lifters should work and how poorly most people utilize them led him to design the bypass system. I fully agree with Dan on the idea that most people do not really understand how to get the most out of their packs, fit-wise. I often cringe when I see folks on the trail with packs that do not fit or are far out of adjustment. It happens all the time. I am tempted to stop them and beg them to let me help them get it adjusted better. They could be so much more comfortable. Maybe that's an article we need - one on fitting and adjusting a pack for the best comfort.

Edited by paul on 12/04/2012 20:05:10 MST.

Dave U
(FamilyGuy) - F

Locale: Rockies
Re: Re: How Packs Work on 12/04/2012 20:26:15 MST Print View

If the frame is stiff enough and slightly taller than the shoulders, then load lifters aren't needed until you get to about the 40 pound mark. Mchale packs are designed this way depending on whether you have the pack in "day pack" mode and lengthened or shortened and set up with the P&G stays (which are amazing, by the way).

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: How Packs Work on 12/04/2012 20:45:03 MST Print View

Very interesting, and thanks for the article David.

Hum ... Clearly I must be a renegade, as my thoughts are very different. Or maybe this article merely confirms many of my thoughts.

The Jam keeps changing? Maybe it STILL hasn't found a good design? Or is it that GoLite are now chasing the fashion market?

> buckling of the backpanel (and thus torso collapse) more likely. The stiffer the
> frame the less likely this is to occur, but it is a universal phenomenon
> nonetheless, save with external-frame packs.
Yes, indeed. The Amercian preoccupation with frameless packs, with all their attendant torso-collapse problems, has not really reached either Europe of Australia. The result is that European packs are, imho, generally far more reliable on long trips. Australian packs seem to be reliable too, although they have not yet got their materials beyond steel&canvas.

My MYOG external frame pack weighs 40 oz. I can carry as little as a few lbs in it, or as much as 45 lbs, in comfort. But note that it has a real frame, and suffers ZERO torso collapse. It does not have to rely on load transfer to the hips either, which is fortunate as I don't have much in the way of hips to support it. Which is entirely consistent with David's comment that 'For example, once the back panel of the Jam was reinforced with an aluminum stay, the mode of failure quickly switched to hipbelt creep.'

OK, OK, I am a curmudgeonly old renegade. But I have to carry a pack so often, and I just don't find the fad of frameless packs to be convincing.... In fact, far too many of them are just ... wierd. I think it is time American manufacturers woke up to reality. (I see Kelty still has.)

Cheers

Luke Schmidt
(Cameron) - MLife

Locale: The WOODS
Re Re How Packs Work on 12/04/2012 21:17:01 MST Print View

David - Great article I'd love to geek out over it but I gotta run, hopefully the thread will still be active when I get back.

Roger - You aren't the only renegade. I like a light (about 32 oz) internal frame pack for longer trips and/or trips where I need to carry more gear.
I do like my little frameless MYOG pack but I only use it when I have a truly light load (usually less then 15 pounds total). At those weights I don't really notice much difference between a frameless pack and a framed pack. Now when I go on longer trips I grab my internal frame pack.

a b
(Ice-axe)
Re: Re: How Packs Work on 12/04/2012 21:22:02 MST Print View

Yea, I used a GoLite Pinnacle for 2,650 miles. Had folding back panel and hipbelt creep.
Switched to an MLD Exodus and used a Ridgerest 3/4 length foam pad inside as my sleep pad and frame sheet.. problem solved for over 5,600 miles now.

In my opinion the design of the shoulder straps has everything to do with the success and comfort of a frameless pack.

Hipbelt only acts to secure the load and transmits nearly no weight.
the hipbelt of the GoLite is way too big and the angle of the shoulder straps and the spacing behind the neck is wrong.

Load lifters are useless and unneccesary if the shoulder straps fit right.

Although, even with proper design these things have their limits carrying anything more than 30 lbs with a frameless pack is asking for pain.
Some manufacturers are upfront about this, others.. not so much.

I agree they are a fad these days... But lets not throw out the baby with the bath water here.
There have been huge strides made in the design of some of these packs and though they may all lack a frame, they are lightyears apart in the way they perform.
I also agree that they have their place and when loaded properly and with lighter loads they can be quite comfortable.
My advice; ditch the Golite junk and try a quality made Mountain Laurel Designs product.
From personal experience, the difference is night and day.

(I was not paid to say this, never asked for or recieved any compensation from MLD to write this or any other testimonial. I actually believe in their designs based on my own experience. Your Mileage May Vary.)

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
re: frameless packs on 12/04/2012 22:10:10 MST Print View

Paul, I have examined but not extensively used a McHale. The first harness on my B&W pack had a bypass-esque lifter system, and while the execution wasn't ideal (seemed like I'd need at least 5-6 inches between the shoulder strap attachment point and that of the lifters) it was enough to slake my curiosity. It is a very clever design. For that pack and the weight it will carry, I don't think I need lifters. If I build or buy a real load monster in the future I'll include lifters.

While having shoulder straps which attach substantially above torso length is indeed required to both not have load lifters and guarantee no weight on the shoulders no matter the load, I don't think most will find this desirable. Indeed with a frameless or lightly framed pack the lack of dynamic mobility such a design creates negates the primary virtue of such packs.

Roger, whether one buys into the benefits of frameless packs is a matter of ideology, not data. They have limits, which are easily understood, and that they fail when pushed beyond those is not an especially poignant critique. What I take issue with is persistent design shortcomings which make many frameless packs work not nearly as well as they ought to. Fairly minor redesigns could give us a Thruway that could for many carry 35 pounds day after day and retain all the benefits of the current iteration.

a b
(Ice-axe)
Re: re: frameless packs on 12/04/2012 22:50:13 MST Print View

"While having shoulder straps which attach substantially above torso length is indeed required to both not have load lifters and guarantee no weight on the shoulders no matter the load, I don't think most will find this desirable. Indeed with a frameless or lightly framed pack the lack of dynamic mobility such a design creates negates the primary virtue of such packs. "

David, I think i disagree.
The success of my frameless pack use and from what i have heard from friends that use them is that ALL the weight IS tranferred to the shoulders in a comfortable way.
NONE of the weight is transfered to the hips, nor needs to be.

My Exodus and Prophet have no load lifters.
Yet the shoulder straps are not attached above torso length.
The design is such that the top of the shoulder strap goes horizontally over my shouler without the pack sagging.

Here is a picture i took some time ago related to just this issue.
.This is a picture of a MLD Prophet, notice no load lifters needed
.
Load lifters are not needed with proper strap design.
Hipbelt is only there to keep the pack stable and transmits zero weight.
The sleep pad stuffed inside along with gear makes the pack ridgid and comfortable.
Light loads of 30 lbs or less make this perfectly comfortable for all day use.

Trying to put the weight on the hipbelt is unneccesary with this load range, pack loading strategy, and shoulder strap design.

(edited to correct some of my ridiculous spelling errors)

Edited by Ice-axe on 12/04/2012 22:52:33 MST.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: re: frameless packs on 12/04/2012 23:19:48 MST Print View

Nice article Dave

I don't think the point is whether any individual agrees with you, because each of us has different conditions.

You and other people say frameless packs are no good because they collapse with more than 20 pounds or so. I never do more than 20 pounds, maybe 22 or 23 occasionally, so no need for a frame. Adding a frame would add weight for no benefit. But then I haven't tested that, but my shoulders are never sore. In the bad old days with a Kelty with 50 pounds and an external frame, my shoulders got sore even though I carried much of the load on my hips.

I have a hip belt on my frameless pack and can put most of the weight on my hips. It does more than just stabilize load. I think it works better to have the hip belt be one unit, cinch it up good. The pack is sewn at multiple places to the waist belt, so there is no torso collapse between pack and waist belt.

I like your three modes of torso collapse - I understand better now.

I have to read you article again a couple times and people's comments...

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: re: frameless packs on 12/05/2012 00:14:29 MST Print View

Yeah, Jerry hit it. Packs are as different as loads are. People are different. Pack comfort for any one individual *will* be different.

Like Jerry, I rarely go out with more than 20 pounds. There is a huge difference between a half pound pack and a two and a half pound pack. The 2 extra pounds is *always* with you. Using a Murmur or Miniposa, the pad pockets on both accept up to 2.5" of fan folded CCF pad. That is a lot of frame for a pack rated at 15pounds. I use it. The Murmur goes along for a week or so with 20-25 pounds. It is definitly not uncomfortable sitting on the narrow belt. And, I have a bad back in my neck/shoulder area forcing me to keep things light on my shoulders.

The big difference between frameless packs and internally framed packs is nothing. It is all a matter of how much you carry and how you arange the gear you *do* carry...a matter of technique. Using a pad as a frame is a good example of dual use gear to accomplish the same purpose as a frame. With modern materials available for packs, there is simply no reason for any serious backpacker to need a framed pack for a week outing weighing more than 16oz. My old Miniposa weighs about 15oz *including* two stays...this is my *big* pack.

Frames are good for heavier loads, about 25-45 pounds. Hopefully, I will never return to my old Kelty, though. Even my old Tough Traveler had a light magnesium, internal frame that weighed about 4oz. It weighs just over 2 pounds (2#2.) It is about 35-40 years old and still goes out every morning, loaded with close to 50 pounds of weight. It has MUCH higher durability compared to the Murmur, but, you *always* carry the extra weight.

Load lifters I really missed on all the UL packs. The Jam is way to heavy to consider, but I am happy to see them returning.

Edited by jamesdmarco on 12/05/2012 05:39:02 MST.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: re: frameless packs on 12/05/2012 08:12:30 MST Print View

Another thing is if you have irregular loads, or different load on each hike, then maybe a frame is better

With frameless, I put the same gear at the same place in the pack every time, so I have an order that works - no hard things poking me in the back, good rigidity. The only thing that varies is how much food and how much a couple other items weigh.

I need to measure torso collapse

Brendan Swihart
(brendans) - MLife

Locale: Fruita CO
Re: Re: Re: re: frameless packs on 12/05/2012 08:47:28 MST Print View

" With modern materials available for packs, there is simply no reason for any serious backpacker to need a framed pack for a week outing weighing more than 16oz. "

Maybe a week outing on wide trails. I do a lot of off trail travel in canyon country, which means lots of rock, willow/tamarisk bashing, the occasional pack haul up or down a drop, and long stretches with no water. A 16 oz frameless doesn't cut it.

Ice-axe, just because the MLD fits you (which is the bottom line here) doesn't mean that everyone should "ditch the Golite junk". Golite clearly has done some things right, as evidenced in this as well as Will R's article linked above. Hell, Skurka carried a Pinnacle 5000 miles across Alaska. I've never used either pack, just sayin' that fit can be different for different folks.

Erik Basil
(EBasil) - M

Locale: Atzlan
Great Article on 12/05/2012 09:12:27 MST Print View

Dave, I think it's an excellent article and one that helps me be more informed as I try to help younger, smaller people with the creation of truly lightweight packs and fitment issues on trail. As a longtime user of an established "Torso Compression Proof" system originated by Dick Kelty, I appreciate the insights beyond what I can easily observe from alongside more modern packs.

Where do you fellas strap the 14" cast iron skillet on them frilly things, anyway? Ho ho.

Dave U
(FamilyGuy) - F

Locale: Rockies
Re: Re: Re: Re: re: frameless packs on 12/05/2012 09:14:23 MST Print View

Load lifters are unnecessary on a framless pack assuming you are using a pack that is close to the correct torso size and not grossly off. With a frameless pack, a load lifter attached to fabric lifts nothing. All it does is bring the pack closer to your back, which can be negated with proper sizing.

David - I was referring to a framed pack and not a frameless pack with respect to having the frame taller than the shoulders (with shoulder strap attachment higher than the crest of the wearers shoulders). My Bad. However, with a frame, it works so well as to be shocking when you first try it. In fact, you then realize that most packs sold and marketed as a specific size are much too short for most wearers. It becomes apparent to consider sizing up in almost all cases to minimize any shoulder fatigue, over long days with even light loads.

Regarding Skurka, he has been using the ULA Catalyst for many trips over the past twelve months, which has a frame. Also, for the majority of his trip across Alaska, he used a ULA Epic with a Pinnacle main bag - this pack also has a frame.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
re: frameless packs on 12/05/2012 09:18:00 MST Print View

"You and other people say frameless packs are no good because they collapse with more than 20 pounds or so."

I said no such thing. While frameless packs is probably an overly general term here, I've demonstrated that a pack with only a foam framesheet can carry over 30 pounds.

Dave U
(FamilyGuy) - F

Locale: Rockies
Re: re: frameless packs on 12/05/2012 09:30:28 MST Print View

But that is still a general statement because that assumes the pack fits to begin with, has long enough shoulder straps for the user, takes into consideration hip structure, etc.

I could carry 50lbs in a school bag. It would suck.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: re: frameless packs on 12/05/2012 13:21:53 MST Print View

"Maybe a week outing on wide trails. I do a lot of off trail travel in canyon country, which means lots of rock, willow/tamarisk bashing, the occasional pack haul up or down a drop, and long stretches with no water. A 16 oz frameless doesn't cut it."

I disagree. I do some High Peak hiking in NY. Some of the woods I bushwack through are nearly impassible with scrub. There is one campsite in particular that requires dropping the pack and literally going sideways through the trees to get to it. 16oz of internally framed pack works fine. The internal frame is a dual purpose sleeping pad.

Lucas Boyer
(jhawkwx) - MLife

Locale: 38.97˚N, 95.26˚W
re: on 12/05/2012 13:28:05 MST Print View

It's really too bad we can't have the variety of packs available via cottage industry in stores to try out. I have never fitted packs but have fitted running shoes for people thousands of times and there is no replacement for testing side by side and comparing the deviation of every model. Unfortunately, retailers are sticking their necks out to carry that kind of inventory.

Some good points of discussion here. I have found a lot of happy miles in an old ULA Ohm w/ the crappy hipbelt. The hoop distributes weight decently and the weight of the pack is a scant 25 oz or so. Dave has commented on the shape of the contour in the back seam. I have a 2011 or so Pinnacle that I am trying to trick out for a heavy packraft load and if you turn it inside out and measure the width of the pack's side panel traveling upward after each measurement, you will find that Golite did put some contour into this pack. I may eventually disembowel the back panel and rebuild it w/ a lumbar support device like Dave mentions, but first I'm going to try mimicking HMG's dual stay system w/ a laminated foam pad and aluminum flat bar.

Paul McLaughlin
(paul) - MLife
Re: re: frameless packs on 12/05/2012 13:31:41 MST Print View

Dave C wrote: "While having shoulder straps which attach substantially above torso length is indeed required to both not have load lifters and guarantee no weight on the shoulders no matter the load, I don't think most will find this desirable. Indeed with a frameless or lightly framed pack the lack of dynamic mobility such a design creates negates the primary virtue of such packs".

I fully agree, and that was partly my point - perhaps not clearly expressed. To elaborate, my thinking is that lifters don't work well on frameless packs (since such packs lack the structure that the lifters require for proper function)and are thus a waste on such; that they are of doubtful utility on semi-framed packs (foam pads and the flimsier varieties of framesheets) and very useful on packs with either stiff enough framesheets or stays (or combinations thereof). But if the pack has stays or a stiff enough framesheet, I doubt very much that it can be as comfortable and as secure (moving with you as you move) without lifters as with, regardless of how well if fits. Having made packs with all the variations - no frame at all, foam pads, plastic framesheets, stays, and with and without lifter straps, I have settled firmly on lightweight stays and skip the framesheets/pads. 3 oz. worth of aluminum gives me weight transfer far better than any foam pad ever will, plus effective lifter strap attachment points.

Of course, when you get light enough you don't need to put any weight on the hips and then you don't need a frame, and the game completely changes. Where that point is varies a great deal individually, which is a big reason why so much debate goes on around frameless packs - some folks are comfortable with 40 lbs on their shoulders, others don't want more than 10. You have to find that out for yourself.

Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
"Frameless" on 12/05/2012 18:54:02 MST Print View

Thanks for a very objective review of these two packs.

As a confirmed internal frame user I STILL contend there is a way to make a "frameless" pack, as I have posted here a few times.

To wit:

1.> Using a CFC pad like the Thermarest Ridgeline. cut it in half laterally, which should put the cut just below or at the hips, depending on your height.

2.> Use wide Heavty Duty Velcro and Gorilla Glue to attatch mating pieces to the cut mat ends for reassembly. Gorilla tape Velcro ends so they don't pull loose on disassembly.

3.> Roll each half tightly and measure the diameter of the roll. Them make 2 fabric tubes in the inside of the pack bag against the back to recieve these rolled mats.

4.> Insert rolled mat halves and use cloth and Velcro top covers to hold them down.

Now you have an internal "frame" that will give good support and padding and permit lift straps to work properly.

Edited by Danepacker on 12/06/2012 13:37:54 MST.

HElinTexas C
(Helintexas) - MLife
Interesting article on 12/05/2012 19:29:30 MST Print View

I bought the GoLite Jam a couple of years ago. I used it on a couple of trips. No matter how I packed it. I hated it. It made my loads feel heavier. I also tended to walk leaning forward ever so slightly.

I happened to take it with me when trekking in Tanzania last year. My guide had a god awful ragged out backpack...basically a kids pack that had been thru the wringer. He had picked my pack up to carry it and he loved the GoLite. It worked perfectly for him. (I ended up giving to him as an extra tip.). It is one of those things where different body types need different packs.

I went to the heavier ULA circuit and I love it. It fits me perfect and I can wear it with a heavier load (than the one I had on my last trip with the Jam) and hardly notice it. I LOVE the weight transfer to the hips. I like the way the shoulder straps fit me. I love the wide waist belt. I love placement of the side pockets. Heavier feel lighter to me.

jeffrey armbruster
(book) - M

Locale: Northern California
How packs work on 12/05/2012 19:54:37 MST Print View

Excellent article. Thanks for your work.

And now let me agree with Roger. 100%. With the caveat that everyone has a different anatomy, etc.

Look, the old adage was 'weight on the frame, frame on the hips, load carried by the legs, which are by far the most powerful muscles in the body.'

I've never been able to find a frameless pack--or even a somewhat frameless pack--that could successfully transfer load off of my shoulders/spine/back and onto my hips. Throw in a bear canister and this becomes doubly true.

I'm curious: if someone were to produce an external frame pack that weighed two pounds or less, would members of this forum consider it? Oh wait, even more: how many members of this forum have even used an external frame pack?

(My external frame pack, which I love, weighs 2 1/2 pounds. I top out at 25 lbs. for six days, including the pack.)

Mary D
(hikinggranny) - MLife

Locale: Gateway to Columbia River Gorge
How Packs Work on 12/05/2012 20:13:51 MST Print View

I used an external frame pack for many years and hated it. It would zig when I zagged and pull me off balance. I guess I always thought that's what packs do!

I now have a lightweight internal frame pack which (when I bought it, before I trimmed unneeded straps) weighed 29 ounces. It will easily support a 35 lb. load, more than my knees and feet can carry. It transfers practically all the weight to my hips, important for me because my shoulders are very pressure sensitive. It has removable aluminum stays so can be used as a frameless pack if I want (I seldom do). Most important, it moves with me so I don't get off balance!

The point above, that load lifters really don't work without stays, definitely is true for my pack!

Stephen Barber
(grampa) - MLife

Locale: SoCal
re: frame pack on 12/05/2012 20:19:00 MST Print View

" if someone were to produce an external frame pack that weighed two pounds or less, would members of this forum consider it? Oh wait, even more: how many members of this forum have even used an external frame pack?"

Absolutely! My wonky back insists that I keep weight off my shoulders and on my hips. My UIA packs do a great job of that, and frameless packs, even at "light" pack weights of 15-20 lbs are a nightmare for me. An external frame pack at 2 lbs would definitely be worth a try.

And yes, I've carried External frame packs for years! My favorite was a Trailwise (? - the Colin Fletcher liked), but it was stolen decades ago, and I was unable to get another. Having started with canvas rucksacks, I still remember my joy and amazement at trying on an old Kelty with a HIP BELT! That was a wonderful experience! :)

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: How Packs Work on 12/05/2012 20:41:37 MST Print View

"It does not have to rely on load transfer to the hips either, which is fortunate as I don't have much in the way of hips to support it."

Hi Roger,

I'm a bit confused. Does this mean you are carrying the entire load on your shoulders? Up to 45 pounds? If so, you can add the honorific "gnarly" to your curmudgeonly persona. ;0)

"I just don't find the fad of frameless packs to be convincing...."

+1 The benefits of a stay system of some kind, either internal or external, seem pretty obvious to me, but then I guess I'm sort of feminine in that I don't tolerate weight on my shoulders very well.

Cheers

Dan Durston
(dandydan) - M

Locale: Cascadia
External on 12/06/2012 05:50:57 MST Print View

" ..if someone were to produce an external frame pack that weighed two pounds or less, would members of this forum consider it?"

ULA Ohm? Great pack. Popular yet still underrated. Carries so much nicer than a HMG Windrider which gets all the press these days.

Ken Thompson
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: External on 12/06/2012 06:15:50 MST Print View

Ohm has the frame inside now.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Pack collapse and load lifters on 12/06/2012 06:47:41 MST Print View

Load Lifters and some sort of support frame are needed with most packs. For pack loads of less than 10 pounds, you can probably skip them, since the pack itself, when compressed supplies enough support. Load lifters are not needed unless the loading exceeds the height of a frame used to support it.
Pack Collapse
The stiffness of the frames makes a huge difference in the performance of a pack. For anything up to about 25#, a fan folded pad works well as an internal frame. For loads up to about 35 pounds, a stiffer frame is wanted. Plastic or metal frame sheets, stays, etc can all be used depending on the load to be supported. For heavier loads an external frame is likely wanted.

Most lightweight, UL hikers or through hikers rarely reach 35 pounds. The exception is during desert hiking where large amounts of water are needed. Each gallon(US) weighs about 8-1/4 pounds or so. It is relatively easy to have a low base weight, fuel and food of about 20 pounds and still carry a 45pound pack. An external frame makes sense for these conditions. More normally, water is not a big weight, though. I typically hike through woodlands carrying about 1liter of drinking water. All else is made up as I go at breakfast and supper. I think this is a little low for many, but even two liters would be plenty for most hikers on a day’s hike...about 5 pounds.
Anyway, all packs can benefit from some sort of frame. A light internal frame, such as a frame sheet or pad, works well for light loads. A heavier frame sheet, thicker/stiffer pad, or, stays works better for mid range loads. External frames work better for heavier loads. What is *not* explained when you buy a frameless pack, is this does not save weight in and of itself. Rather, it saves weight *indirectly* by allowing the dual use of a sleeping pad (in whatever arrangement, tube, fan-folded, or structured) as a frame for lighter loads, ie, usually up to 20-25 pounds.

My conclusion is that load lifters are still needed on “frameless” packs for loads of ~20 pounds, because any experienced hiker knows he needs the support of some sort of internal frame. It really doesn’t matter that a pad is used or a “dead weight” frame sheet. The hiker will most likely use some sort of internal frame (or in the case of Gossamer Gear or other packs with pad pockets, a light duty “external” frame.) Load lifters, will help stabilize the load against collapse.
In the case where the shoulder straps come even with the frame, pad pockets or sleeping pad, clearly some compression of the pack will help to maintain stiffness against both front and back collapse as shown.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
pack fit on 12/06/2012 07:04:04 MST Print View

"It's really too bad we can't have the variety of packs available via cottage industry in stores to try out. I have never fitted packs but have fitted running shoes for people thousands of times and there is no replacement for testing side by side and comparing the deviation of every model. Unfortunately, retailers are sticking their necks out to carry that kind of inventory."

Well said sir.

Dave U
(FamilyGuy) - F

Locale: Rockies
Re: External on 12/06/2012 08:24:16 MST Print View

"Carries so much nicer than a HMG Windrider which gets all the press these days."

Ooh...ya, no.

Generalizations are nasty. Did you not see the posts on fit?

I know you had one of the original ones. The Windriders use the stays from the Porter and even the same belt for the 3400 model.

Edited by FamilyGuy on 12/06/2012 08:48:09 MST.

Martin RJ Carpenter
(MartinCarpenter) - F
re: pack fit on 12/06/2012 08:27:33 MST Print View

Indeed, especially as its so important and can be so seemingly randomly individual. I certainly find the idea that it can be done using purely back length/waist size somewhat entertaining.

I wonder how many measurements it'd take to get custom packs fitting genuinely well on a reliable basis. Or why I'm a randomly problematic case :)

We actually get vaguely lucky in the UK in that the only people who import some of the cottage industry American packs are an internet based operation who also effectively have a showroom in their warehouse.

So I could, for instance, discover that - the massive range of sizes non withstanding - nothing that ULA did fitted me well.... In fact my main pack for the moment worked much better when I'd removed the lumbar pad and switched to a more flexible back system.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: pack fit on 12/06/2012 08:38:25 MST Print View

It would be helpful to try a pack in the store, but

Do you really need to load a pack up and carry it on a trip to know if it's right?

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
re:re: pack fit on 12/06/2012 08:58:32 MST Print View

"Do you really need to load a pack up and carry it on a trip to know if it's right?"

Yes.

Jason Elsworth
(jephoto) - M

Locale: New Zealand
How Packs Work on 12/06/2012 15:07:05 MST Print View

"Do you really need to load a pack up and carry it on a trip to know if it's right?"

When buying cottage packs I have resigned myself to having to try them in the field and then sell them on Gear Swap if they don't work out.

Mary D
(hikinggranny) - MLife

Locale: Gateway to Columbia River Gorge
How Packs Work on 12/06/2012 16:02:47 MST Print View

"When buying cottage packs I have resigned myself to having to try them in the field and then sell them on Gear Swap if they don't work out."

I had all my gear, plus a mockup bag (in weight and bulk) of a week's food, ready and waiting when my "cottage" pack arrived. I tried the pack on, adjusted it, loaded it up, adjusted it again, and then took a "hike" around the house for two hours with the loaded pack. I was extra careful to keep the pack clean and returnable. It was a very boring hike, but at least I knew by the end of it (when I was just too bored to go on!) that I had the right pack! Just to be sure, I tried it again the next day.

I felt that it was well worth the effort to keep the pack in new/returnable condition. At least that way, you're only out the shipping cost. If you sell it, you can't get the full price of the new pack.

Edited by hikinggranny on 12/06/2012 16:06:17 MST.

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: How Packs Work & Load LIfters on 12/06/2012 16:33:21 MST Print View

Like anything else you need the right tool for the job. I drank the frameless kool aid and it did not taste good. For total loads much above 15 pounds the packs were uncomfortable and fragile to boot. I have gotten my gear weight so low that a couple extra pounds for a real internal frame pack still keeps me well under 10 lbs PBW and often near SUL. Plus I can carry a couple weeks of food and a gallon of water comfortably. No need to frequently interrupt a trip and go back into civilization and muck up my solitude for supplies.

I disagree that all packs need load lifters. If the pack extends much over the torso and if the weight changes the dynamics, then lifters work if they are properly adjusted. Lifters don't work well if they are not connected to a frame extension. I 2nd the comment about checking out McHale's website. I researched for 6 months before buying my LBP and I thought I knew a lot about packs given all my years of experience and research during those years. During the fitting process Dan taught me a lot about packs. The biggest thing was how to adjust the stays... and most important was that his stays are so strong that even though my spine required quite an extreme bend in the stays, Dan's stays will not compress or collapse. Also you will see that his lifter set-up is meant to be removable including the by-pass harness that adjusts the lifters.

My McHale Bump has very comfortably carried 35 lbs and it does not have load lifters. The LBP also does extremely well with the load lifters removed and 35 lbs. This is the most I have carried with either pack.

Dan Durston
(dandydan) - M

Locale: Cascadia
Ohm on 12/06/2012 16:35:53 MST Print View

"Ohm has the frame inside now."
Normal Ohm is still external. Ohm 2.0 has the frame inside.

"Ooh...ya, no.....I know you had one of the original ones. The Windriders use the stays from the Porter and even the same belt for the 3400 model."
I still I have it. Waterproof is awesome. The stiffer stays are good to hear, as the original ones are much too soft. For whatever reason(s), I have to pull them out to unbend/warp them occasionally.

Regardless of those changes, IMO the stays are located too close to the center of the pack. They don't connect to the hipbelt wings that well, which limits what this pack could otherwise carry.

While I'm critiquing:
- the foam backpad should be removable so it can be fully utilized
- the Y-strap/bear canister system up top is a pain when not carrying a canister and should be removable. I cut it off.
- the internal seam tape peels off over time
- lower side compression straps interfere with side pockets
- the buckles on the roll top should be male on one side, female on other, so you have the option of buckling the top shut to itself (normal dry bag style) without using the side straps. This is needed when pack is very full.

Some pros:
- external mesh is nice and durable
- fabric is great, although non-white would be better (turns brown).
- hipbelt pockets are well done

Edited by dandydan on 12/06/2012 16:42:55 MST.

Dave U
(FamilyGuy) - F

Locale: Rockies
Re: Ohm on 12/06/2012 16:44:44 MST Print View

"They don't connect to the hipbelt wings that well, which limits what this pack could otherwise carry. "

Don't need to. The belt has rear stabilizing straps that suck the lumbar in.

FWIW, my Mchale pack does not have the belt attached to the frame. This is an internal frame we are talking about. The belt only needs to be attached to the frame for an external.

Rex Sanders
(Rex) - M

Locale: Central California Coast
Re: How packs work on 12/14/2012 11:12:52 MST Print View

Seems impossible to design one pack that fits a wide range of people really well. If you want a pack that works well for you, you need to try a lot (and return or resell a lot), or get a custom pack.

Now I understand why some packs get rave reviews, but I hate them when I try them.

book says:
"I'm curious: if someone were to produce an external frame pack that weighed two pounds or less, would members of this forum consider it?"

Ten years ago I tried the LuxuryLite StackPack (just over 2 pounds), and it was agony for me, even after many adjustments and part rearrangements. Must fit some other people OK because he still sells them.


"Oh wait, even more: how many members of this forum have even used an external frame pack?"

You mean Kelty, North Face, Trailwise, LuxuryLite, and some no-name canvas-and-aluminum pack my mom bought me for Boy Scouts?

Most comfortable pack I ever used, regardless of construction, was an Alpenlite internal frame pack from the early 1980s.

Though my new HMG Windrider 2400 is pretty good fit, too. Got lucky on that one.

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: re: frameless packs on 12/14/2012 16:32:00 MST Print View

"Having made packs with all the variations - no frame at all, foam pads, plastic framesheets, stays, and with and without lifter straps, I have settled firmly on lightweight stays and skip the framesheets/pads. 3 oz. worth of aluminum gives me weight transfer far better than any foam pad ever will, plus effective lifter strap attachment points."

Hi Paul,

In this context, what do you think of the OHM/Circuit design? The OHM has been nearly perfect for me, but I'm curious what you think of it's design for a broader set of users.

Tom

Paul McLaughlin
(paul) - MLife
Re: Re: Re: re: frameless packs on 12/14/2012 16:52:06 MST Print View

Tom - I haven't had my hands on either pack, so I can only comment on what I see in the pictures. I can't tell you what I think of the frame and its load transfer capability.

The one thing I don't like from what I see is that the belt is attached to the sides of the pack. I have found that I get the best performance if the belt attachment points are about 6-8" apart. Wider than that, at least for my average build, and you tend to get gaps at the "corners" - which can only be eliminated by tightening the belt enough to compress the pack contents far enough to get the belt to wrap tightly around the hips. Obviously the degree to which this happens will vary depending on body shape. The Circuit appears to have a narrower attachment, although I don't like the way the attachment is wider at the top than at the bottom. That's the opposite of what I would do.

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: Re: Re: re: frameless packs on 12/14/2012 17:25:21 MST Print View

"The one thing I don't like from what I see is that the belt is attached to the sides of the pack. I have found that I get the best performance if the belt attachment points are about 6-8" apart. Wider than that, at least for my average build, and you tend to get gaps at the "corners" - which can only be eliminated by tightening the belt enough to compress the pack contents far enough to get the belt to wrap tightly around the hips. Obviously the degree to which this happens will vary depending on body shape. The Circuit appears to have a narrower attachment, although I don't like the way the attachment is wider at the top than at the bottom. That's the opposite of what I would do."

Thanks for the input, Paul. Grist for my mill.

FWIW, the OHM 2.0 uses the Circuit hipbelt and now attaches closer to the middle of the pack, more or less in the 6-8" range you mention. I have used all 3 versions of the OHM, and found that the 2.0 is by far the most comfortable and effective at transferring the load to my hips. This is a really big deal for me, as I hate weight on my shoulders. So, it seems that they are at least evolving in the right direction, at least for my body type.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Re: Re: re: frameless packs on 12/14/2012 18:39:43 MST Print View

Maybe have the hipbelt be one belt, that goes around your hips

Then, have the pack attach to the hip belt

Paul McLaughlin
(paul) - MLife
Re: Re: Re: Re: Re: Re: re: frameless packs on 12/14/2012 19:45:49 MST Print View

Jerry - I agree. That's what I do on my lightest packs - make a belt and sew it on. For somewhat heavier loads, like the pack I use for backcountry ski trips, I find a lumbar pad is a good idea, although that can be part of the belt if you want to do it that way. THE most comfortable pack I ever made had the hipbelt one piece, and attached to the pack only by two points at its bottom and one at top center. Involved velcro and webbing and worked great, but heavier than just sewing the belt on, requires a beefier belt construction(and thus heavier again) and makes no difference if the load is under 30 lbs anyway.

Bruce Kolkebeck
(cjcanoe) - M

Locale: Uhwarrie National Forest
UL packs on 04/02/2014 13:46:20 MDT Print View

My advice to folks who are starting out buy UL equipment first and then buy the UL pack. Heavy loads will kill you with a UL pack. Backpacking on my own with my Jam70 is great. At Philmont Scout Ranch last year all the stuff I carried for the crew plus the food and a gallon of water was not UL. It hurt. When I do my thru I'll take the Jam.

BK

Bruce Kolkebeck
(cjcanoe) - M

Locale: Uhwarrie National Forest
oops on 04/02/2014 13:48:04 MDT Print View

I just posted a reply to a two year old article. Still a very helpful article.

BK