Forum Index » Editor's Roundtable » MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs


Display Avatars Sort By:
Maia
(maia) - MLife

Locale: Rocky Mountains
MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/15/2013 13:30:21 MDT Print View

Companion forum thread to:

MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs

Kronos Master of Fate
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/15/2013 14:02:12 MDT Print View

This feature is sometimes still available in off the shelf packs such as

http://www.jandd.com/detail.asp?PRODUCT_ID=FZA

and is also included in this pattern.

http://www.therainshed.com/patternpages/RSpatternPages_/RS150alpine.htm

Please use " or inches instead of in. It will read better and be easier to understand without having to read it twice.

Edited by kthompson on 10/15/2013 14:04:22 MDT.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
S shapes on 10/15/2013 15:00:27 MDT Print View

Ken, I assume you read everything I write at least twice.

The last ~18 months of experimenting has led me to believe the above technique has almost universal application. There does not seem to be much if any anatomical variation here. This is not the case with lumbar shape (very far from it), which makes me skeptical of the "s" contouring boasted of by Jandd and others.

Kronos Master of Fate
(kthompson) - MLife

Locale: Behind the Redwood Curtain
MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/15/2013 17:22:28 MDT Print View

I usually have to read your stuff twice. Usually after consulting a dictionary.

It makes sense to add shape. Our backs are far from flat. I only meant others have gone done the road to a pack that is actually designed to be worn by a human. Not just look sellable.

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/16/2013 10:31:37 MDT Print View

Dave, any comments on combinations of this technique alongside a single-stay system? Good, bad, unnecessary? Also, in this system with a frameless application do you still typicall use a sheet of closed cell as a frame sheet?

Bruce Kolkebeck
(cjcanoe) - M

Locale: Uhwarrie National Forest
material on 10/16/2013 10:48:57 MDT Print View

What again are you using for the stiffener? I can't recognize the material.

Thanks,

BK

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/16/2013 11:20:31 MDT Print View

The contoured side panel looks like a good design feature and it is essentially weightless. As I read, I wondered if load lifter straps are actually accomplishing the same thing--- not that they are a better alternative, but they tweak the top of the pack to fit the shoulder curve in the same way. If so, the side panel contour has the advantage of less hardware, assembly cost and lower weight.

In looking at the photo of Will and the pack with gaps, it brought to mind something I have seen with others on the trail: some hikers don't tighten their shoulder straps properly and the pack is an anatomical mess, rotating down and out away from the shoulders. In the photo of Will, the pack has some large wrinkles, indicating to me that it may not be over filled and just worn too loose on the shoulder straps.

The side panel contouring looks like an excellent choice for pack designs that don't continue above the shoulder strap upper connection. In those designs, load lifters are a useless addition I think.

As far as s-curve cuts that contour into the lumbar area, I think that some lumbar curve is quite helpful to distributing the load to the hips and more stable as well as more comfortable. Getting the right torso length is critical. Note that many internal frame packs have curved stays and the option to tweak them to fit the user. Also, with unframed packs, proper loading and use of side compression straps can add a virtual lumbar curve.

David Chenault
(DaveC) - BPL Staff - F

Locale: Crown of the Continent
frame details on 10/16/2013 11:24:25 MDT Print View

Sam, for a single stay pack it certainly wouldn't hurt, but isn't strictly necessary either. For frameless packs I do prefer a slot of some kind for the foam pad. Inside for a pack like the white one which will get beat on, outside (a la GossGear) for a pure backpacking pack.

Bruce, not sure what you mean by stiffener?

Sam Haraldson
(sharalds) - MLife

Locale: Gallatin Range
MYOG: Contoured Side Panels for Improved Load Carry in Frameless Packs on 10/16/2013 12:31:58 MDT Print View

Thanks, Dave.

Bruce Kolkebeck
(cjcanoe) - M

Locale: Uhwarrie National Forest
Panels on 10/16/2013 14:14:18 MDT Print View

What are you making the panels out of? Thanks, BK

Bruce Kolkebeck
(cjcanoe) - M

Locale: Uhwarrie National Forest
pack on 10/16/2013 14:26:38 MDT Print View

Sorry Dave! I miss-read the article. I read it again and now understand how you achieved the fit. I'm going to try that. Thanks. Great article.

BK

scott Nelson
(nlsscott) - MLife

Locale: So. Calif.
Why not contour for the lower back, too. on 10/16/2013 15:02:49 MDT Print View

The straight sides on frameless packs has always puzzled me. Dave is right to stress the need for a side contour that follows your upper back and shoulders. But why not continue on and contour the lower half of the pack so that it follows the shape of the small of your back? Too many frameless packs seem based on the Jardine Breeze. The straight side seams are easy to cut and sew. Simplicity itself. But doesn't the pack have to collapse to follow your back shape? The Jensen Rivendale pack really was shaped to your body. (They were just really awkward to pack and get things in and out of.). Gregory packs did this well as an improvement on the old Lowe Alpine packs. Mountainsmith's claim to fame when it started was a strap that pulled the pack into your lumbar. I seem to see a gap in the small of Dave's back in these pictures. It is not that hard cut side panels with an S curve that follows the shape of a fitted back stay. The back panel can still be rectangular or contoured if you want to play with the width of the pack. My two cents Scott

"Upon further review..." I found a great post at outlivingblog that the straight sides on the lower part of the pack actually helps bring those sides closer to the wearers back. He shows how vertically curved sides end up a distance away from the body due to the round curve of the back if you think of slicing it horizontally. I.e. The side of your hip is 4-5 inches forward of the plane of your spine. He also stresses
the need to consider this when shaping the bottom of the pack. You should scoop out the bottom where it connects to the back panel to let your body move in toward the pack. This is what the straps from the side of the pack to the hip belt are supposed to help do..

Edited by nlsscott on 10/19/2013 12:49:09 MDT.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Why not contour for the lower back, too. on 10/16/2013 15:16:03 MDT Print View

That's what I was getting to earlier. I think it needs careful packing and good compression strap design. If you don't put your insulated gear in stuff sacks it is easier to pull this off I think-- a big soft and malleable lump in the bottom against your back with the pack sides pulling it into shape.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Why not contour for the lower back, too. on 10/16/2013 15:22:32 MDT Print View

I like the articles and threads about pack design, this being a good one.

If you have stuff sack(s) inside your pack, you can sometimes position them to make the pack fit better, like to avoid the problem of the pack being one big cylinder (log) against the middle of your back. Like, you can have the stuffsack be a cylinder going sideways, which will be flat against both sides of your back.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
"All things equal, a frameless pack will also always be lighter than any other alternative." on 10/16/2013 18:01:31 MDT Print View

Even the Arc Blast?

Paul McLaughlin
(paul) - MLife
good for internal frames as well on 10/16/2013 18:33:45 MDT Print View

I don't make frameless packs anymore(don't see the point when my stays are only 3 oz and they make life so much better), but I have always built my internal frame packs with contoured side panels.

peter vacco
(fluff@inreach.com) - M

Locale: no. california
Re: good for internal frames as well on 10/17/2013 07:08:59 MDT Print View

there are darn few straight lines in nature. and even those that look straight are bent if you walk around and look from the side.
(peter falls squarely into the "heck, it's only 3 oz, so let's just have a frame" school of thought)
i don't even sew the side seams on stuff sacks straight anymore.
nice article, it's food for thought.

Thank You Dave.
v.

Tony Ronco
(tr-browsing) - MLife
Re: All things equal, a frameless pack will also always be lighter than any other alternative on 10/17/2013 07:54:45 MDT Print View

RE: "Even the Arc Blast?"

Yes. A frameless Blast is 3.5 oz lighter than the Arc.

http://www.zpacks.com/backpacks.shtml

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
zim on 10/17/2013 12:42:16 MDT Print View

Zimmerbuilt told me he could make them contoured for 10$ extra.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Frameless Blast on 10/17/2013 17:20:31 MDT Print View

Article: "Even a completely frameless, grocery sack style pack like the Blast places seams in certain places which predispose it to assume a certain shape. Stiffer fabrics, [you mean heavier fabrics?]

such as the heavier cuben fiber and most Dimension Polyant laminates, will tend to maintain that shape better than more pliable fabrics like silnylon. Altering this shape by manipulating the contents and how they are packed (for example;inserting a

rolled or folded foam pad) [How much weight are you adding here that need not be added to the Arc? More than the Arc's frame?]

becomes increasingly problematic as the pack nears maximum capacity"

And just how effective are those heavier fabrics and rolled or folded foam pads? Do they transfer weight anywhere near as effectively as the Arc? I doubt it.]