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Frameless Backpack Suspension Systems
The purpose of this thread is to discuss frameless backpack suspensions, load carrying capacities, design considerations, packing methods, and other factors that contribute to making a frameless backpack more comfortable to wear. The reader is referred to the following articles as basis for this discussion:
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Tony Burnett
(tlbj6142) - F

Locale: OH--IO
Re: Re: torso length... on 11/22/2003 15:52:00 MST Print View

The pack did tend to pull away all the time. I always felt like I needed to tighten the shoulder straps throughout the hike. Part of this is due to the fact that the pack is rather deep. Which is made worst by the additional 2" displacement from your folded pad.

I read the "new" Moonlight is suppose to be more tall and shallow rather than short and deep.

Edited by tlbj6142 on 11/22/2003 15:52:58 MST.

Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Re: Re: Re: torso length... on 11/22/2003 15:54:56 MST Print View

Ah, yeah, you're right. I meant 'shorter' but hit the post button before rereading my post. Sorry for the confusion.

Ron Moak
(rmoak) - F
Re: torso length... on 11/22/2003 15:55:37 MST Print View

>> I found the Moonlight to be way too long. The shoulder straps came straight up off of my shoulders rather than around the top and then down an inch or two. With this particular pack, it seems like the torso length is fixed at the "width" of your pad. Typically 20", less 1.5"-2", as the hipbelt's midline is a bit up from the bottom of the pack. I returned the otherwise beautiful pack because my shoulders got sore after carrying a 22# load on a 18mi day-hike (weekend load).

We’ve had mixed reactions to the height of the Moonlite. If the hip belt is attached to the bottom connectors you’ll get about 18” inches to the top of the pack. Both packs sent to you and Backpacklight were the same production packs. So there may be some differences in where the belt was attached.

We’re in the process of completely revamping the Moonlite into a new pack. Again the minimum torso height is dictated by the height of the pad. Which will be about 18”. In addition the new pack has a couple extra adjustments to raise it in two increments to 20”.

The pad pocket has been completly integrated into the pack. It is still accessed from the rear to provide quick access to your pad. The integration allowed us to raise the pack and cleanup the somewhat awkward connection of the shoulder straps to the pack.

It should be noted that originally the Moonlite was designed specifically as a vest pack. Using the Vest, you’re a little less dependent of torso length. This is primarily because the pack weight is transferred to your core instead of your hips. We added the hip belt much later in the design cycle.

For the new pack we’ve incorporated a traditional wrap around hip belt. This helps keep the pack centered better on people with narrow waists. There are additional lash points to maintain the rigidity of the pad.

The Moonlite suffers a little from being a bit too deep. This requires a bit more practice packing the pack to insure the weight is properly centered. Otherwise, the pack will tend to cantilever out backwards. We resolved that by decreasing the depth by two inches and designing in a arch into the back. Together they will keep the load closer to your center of gravity.

I hope his helps.

Ron Moak
Six Moon Designs

Edited by rmoak on 11/22/2003 16:40:26 MST.

Eric Kammerer
(EricKammerer) - MLife
Re: Sleeping Pads for Frameless Pack Suspensions on 11/22/2003 17:12:28 MST Print View

I've used both inflatable and non-inflatable pads. What works best for me is a U-shaped support created by folding the pad in sections too long to just cover the back. This hybrid allows me to pack the pack more efficiently than a cylinder, but still offers some of the increased rigidity. It also is less likely to move around inside than a flat pad.

Andrew Mytys
(amytys) - F
Rolled pad -vs- frame on 11/22/2003 18:37:02 MST Print View

While I fully agree with your article's conclusion, that a "rolled cylinder" pad is not "just as good as a frame" for transferring loads between the shoulder straps and hip belt, it may be, in some cases, good enough... from the perspective of "user comfort".

Using scientific measures to monitor pad performance may show tye idea lacking, especially when compared to a real frame, but from a subjective standpoint of "how it feels", the difference between rolled pad and no pad may monumental, and the difference between frame and no frame w/rolled pad might be "not that big".

I think that it is from this perspective that a lot of the manufacturers and UL hikers are making their claims.

I would have to personally agree. I own two frameless packs - a GoLite Breeze and a ULA P-1. Both carry substantially better in the "feel" department than going sans pad. I would also add that pad material and configuration do indeed matter. Loading up my P-1 with a 25 pound load, it "feels best" when that load is held within a rolled cylinder composed of closed cell, specifically a Cascade Designs Ridge Rest 3/4. If I change the pad to a CD UL Therm-A-Rest 3/4, the pack is not as comfortable on my back, and I can feel more of a "droop" in the load near my lower back. One can also see the difference by viewing the loaded pack from the outside.

It seems that pad configuration also makes a difference. As with the rolled closed cell debate, opinion may vary as "comfort" is subjective. At any rate, a 3/4 RidgeRest folded three times over and used as a stiff back "pad" does not seem to offer the same level of support as the roll technique. I found this interesting, as I was fully expecting the thickness of the "wall" against my back to perform better than a single layer of pad.

Finally, I'd like to suggest that the more fixed and solid an object is that the pad can roll around, the better it will perform. I hike with an REI 2.5 gallon folding PVC camp bucket (yikes... 6.3 oz!). At any rate, I fill it with miscellaneous items - cook pot, fuel canister, first aid kit, sleeping bag, etc). Then I roll the RidgeRest around the bucket, and stuff the entire thing into my pack. The bucket sits at the bottom of the pack, getting my food and any other gear that didn't fit into it thrown on top.

This system has worked the best for me, in terms of creating a pseudo-frame in a non-framed pack, using both my ULA P-1 (with hip belt) and GoLite Breeze as packs.

Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Re: Rolled pad -vs- frame on 11/22/2003 18:51:38 MST Print View

>> from a subjective standpoint of "how it feels", the difference between rolled pad and no pad may monumental

Especially at lighter loads.

>> and the difference between frame and no frame w/rolled pad might be "not that big".

Especially at lighter loads.

Food for thought.

Robert Stevenson
(Tynicas) - F
Re: Sleeping Pads for Frameless Pack Suspensions on 11/22/2003 23:45:22 MST Print View

I currently use a 3/4 Ridge Rest from Cascade Designs rolled into a tube inside my large size Golite Dawn. The pad is still 20 inches wide, but I'm thinking about altering it to be 18-19" wide both for weight and because the bag doesn't quite close all the way at the top currently with a full load due to the pad.

However, I'm very happy with how the pack carries in this configuration up to 18 lbs (the most I've had cause to carry so far).

John Davis
(JNDavis) - F

Locale: Isle of Man
Re: Sleeping Pads for Frameless Pack Suspensions on 11/25/2003 10:34:46 MST Print View

Many years ago an old soldier told me to scoop out holes for hip and shoulder points. I did this while exhausted on a pebble beach and slept like a log. Sharing weight between hips, shoulders and waist cut the pressure on the points. I am not prepared to dig holes in good turf, so form a shallow ridge from clothes which supports the small of my back/waist area. With this technique, complete comfort can be obtained without any pad. On turf, in summer, a good groundsheet is more important than a pad.
My groundsheet, an Akto footprint, tucks in anywhere there is space.
Best wishes, John.

Edited by JNDavis on 11/25/2003 10:39:21 MST.

Ben Klocek
(benklocek) - BPL Staff - MLife

Locale: SF Bay Area
How do you pack your pack? on 11/25/2003 11:26:24 MST Print View

Where do you put the heavy items? Light items?
Do you use stuff sacks for your soft goods, or stuff them in the crannies?

I use a Breeze, with a UL Thermarest 3/4 in a L shape for support, but my gear tends to fill up the pack and make it firm. I would like it to be a bit less tight.

Will Rietveld
(WilliWabbit) - MLife

Locale: Southwest Colorado
Re: Sleeping Pads for Frameless Pack Suspensions on 11/25/2003 19:57:52 MST Print View

I use a section of fairly firm closed-cell foam pad (no brand name)cut down so it fits me from shoulders to hips, to which I have attached a Therm-a-Rest stadium pad at the hip end. It weighs 11 oz and fits into the outside sleeve of my G4 pack. The foam pad is folded twice and sandwiches the stadiium pad, which I leave inflated to the right level. This pad stiffens my G4 and gives it more structure. I can't use it in my GoLite Breeze because it takes up too much room. The "suspension" created by the pad arrangement makes the pack carry a little better. My pack weight is usually in the 15-18# range, total weight, for a 3-4 day summer trip. Thats really all the weight I care to carry in the G4 pack; above that its less comfortable. I haven't read the article on frameless pack suspensions yet, perhaps I can get some ideas from that.

I'm glad to see this more technical and focused forum. Keep up the good work! WilliWabbit

Doug Johnson
(djohnson) - MLife

Locale: Washington State
Re: How do you pack your pack? on 12/10/2003 16:34:43 MST Print View

I also use a Golite Breeze. When travelling solo, I put my 3/4 ultralight T-rest against my back like you. From here my bag and down jacket go into a HUGE waterproof stuff sack on the botton, uncompressed. Next, I have a stuff sack of clothing (waterproof), my ti kettle and stove, food, near the top. I use the big outside pocket all the time- my Tarptent goes there as well as well as my and waterpurifier (gravity system) and shell. The side pockets hold my random bag (compass, headlamp, etc.), my cameral, and my platypus bags. My best solution for fit is punching the back-facing side of my pack until it's more flat- this improves comfort dramatically and I do it every time. Doug

Edited by djohnson on 12/10/2003 16:35:15 MST.

Jin Elkins
(deoredx) - F
Testing v. Real World Performance. on 01/03/2004 17:23:37 MST Print View

Interesting to see how poorly the Katahdin performed in the tests. This makes me wonder how well the test data relates to the real world comfort and performance. After using a Dawn, Aether 45 (BPL tested the 30), and now a Katahdin I find the comfortable load carrying abilities of the Katahdin Far exceed either the Dawn or the Aether. The main advantage the Katahdin has over the other two were the compression system and the padded hipbelt. I use a POE 1" thick 3/4 length self inflating mummy pad semi inflated and stuff a Tarptent Cloudburst, WM Megalite, and the rest of my gear in the tube. My gear compressed around the tent poles serve to make a VERY solid structure and I see very little sag from my pack. In fact, I can remove all the load from my shoulders and carry the load 100% on my hips and the pack carries as well as my internal frame packs. From my expereince with frameless packs I find that what you pack, and how well it fits in your pack has more to do with how well frameless pack carries then the pack itself.

Charles Ruefenacht
(cruefenacht) - F
G4 Pack on 01/09/2004 00:35:28 MST Print View

My son and I have had ours for 2, maybe 3 years. Maiden voyage was scout 50-miler, actually 70 miles. Had one seam failure which Glen Van Peski fixed pronto. Took a little to get used to but is the most comfortable pack I've used evolving from Sierra Designs frame, to REI, to Mountainsmith internal to Dana Design Bridger. Now that I'm an old geezer, I'm sticking w/ the G4 until Glen comes up with something better. A couple of my friends also have the G4 too.

Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Testing v. Real World Performance. on 01/09/2004 16:45:14 MST Print View

>> Interesting to see how poorly the Katahdin performed in the tests...This makes me wonder how well the test data relates to the real world comfort and gear compressed around the tent poles serve to make a VERY solid structure

I do not dispute your findings at all. The important take home from this is that how you pack your pack makes a big difference. The minute you changed your packing technique to deviate from the test packing technique described in the load suspension articles, you deviated from test conditions and thus, results are no longer comparable. What the test conditions are able to show, is that for a moderately dense load where base soft goods densities are the same from pack to pack, one pack maintains torso stiffness better than another. That's it. It is a testament to a pack's design if it scores well on these test. It is not a guarantee that it will carry well for all people all of the time. Nor do the tests guarantee that a poorly performing pack (in the tests) are going to carry poorly for all people at all times - your Katahdin experience validates that. I think that the test data does suggest that packs that perform poorly in test conditions need more attention on the part of the user in order for them to carry well on the trail.

Justin Gunn
(biggunn) - F
The forthcoming ULA FUSION... on 02/10/2004 01:24:42 MST Print View

I am an ever evolving lighter-and-lighter-weight backpacker who purchased one of ULA-Equipment's custom P-2 packs with much satisfaction. However, since having lightened my load significantly of late, I find that the P-2 is far too large of a bag. Especially for 2-3 season use.

Well, Brian Frankel at ULA-Equipment looks like he may just have done it again. With his soon to be released Fusion pack, he essentially introduces a main pack bag (not including collar or external pockets) around 800 cu smaller than the P-2. This new bag utilizes a sleeping pad for the suspension much like the GVP G-4, but suplements this with a carbon fiber hoop-style frame. It will reportedly come in right around 2 lbs. and carries up to 30 lbs. without getting huffy. I can't wait to try one with the new Therm-A-Rest Prolte 3 Regular (I'm 6'3").

Brian tells me the packs should be available by March 2004 and I will certainly share my impressions back here at once I receive mine.

Always searching for the latest-greatest-lightest-weightest!

Edited by biggunn on 02/10/2004 01:26:22 MST.

Fred Engel
(fredengel) - F
Re: torso length... on 02/22/2004 18:33:49 MST Print View

Splitting 1" hairs and weight transfer.

The original article states,
>>"The iliac crest is about one inch higher than >>the point at which the centerline of a pack's >>hip belt should rest"

This tells me that the centerline of the belt is lower than the iliac crest.

This post states,

>>2) the big one - that the ideal position of a >>hip belt is having its centerline about an >>inch above the iliac crest."

This tells me the opposite of the original statement?

I have noticed that a wide padded hip belt formed in a semi circle when flat ends up with a truncated conical shape when curved. With the narrow end upwards this tends not to slip and snug better over the iliac crest. Additionally, a wider belt with stiffer foam, or a layer of plastic, seems to "transfer" load where as a flimsy narrow belt tends to "hold" the load via constriction and not by transfer.

Any similar or differing observations?

Nate P
(nate37) - F
Re: Sleeping Pads for Frameless Pack Suspensions on 02/28/2004 23:35:18 MST Print View


Edited by nate37 on 05/05/2008 00:11:57 MDT.

Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Re: Re: torso length... on 02/29/2004 01:04:54 MST Print View

Sorry, Fred. Typo in my original post. I've corrected the post.

Ryan Jordan
(ryan) - BPL Staff - MLife

Locale: Greater Yellowstone
Re: Re: torso length... on 02/29/2004 01:13:19 MST Print View

Sorry, Fred. Typo in my original post. I've corrected the post.

Re: Sleeping Pads for Frameless Pack Suspensions on 05/04/2004 21:29:02 MDT Print View

I use a Z-Pad because it conforms to the backpack shaspe well for support