An unconventional MYOG pack

[Jan Rezac]

See next post…

[Jan Rezac]

Here’s a backpack I made that has some unconventional features. I like a pack to have flat rather than tubular shape – having the center of mass closer to the back makes a big difference in how the pack feels. Without a solid frame that would enforce such shape, it can be achieved by using a vertical divider that shapes the pack into two tubes rather than one. The divider is placed only in the upper 3/4 of the pack, so that there’s space for some larger item (usually sleeping bag) at the bottom. The divider also makes the pack more rigid, so it can carry more weight than a single-compartment frameless pack.

This is my third pack using this design. The first one was just a proof of concept prototype. The second one was a top-loader made of heavier materials. Packing such a pack from the top is a less convenient than of a single-compartment pack, so the third version uses zippers on the sides of the pack. It could be combined with the collar and lid used in the second version, but I opted for a closed top to save weight. The access to the pack is now really easy (as long as I remember what is packed at which side – color-coded zipper pulls help here), and I don’t miss the old design at all.

I’m really happy with how it turned out. It’s almost perfect for the intended use – one week mountain trips in the summer, or weekends with some extra gear. I’ve taken it on one longer and multiple weekend trips, and it worked great.

Some technical notes:

• It’s made mainly from the hybrid DCF fabrics. It weights 626 g (22 oz).
• The backpanel is padded with piece of a closed cell foam pad. The divider makes the pack more rigid, it keeps its shape without collapsing up to moderate loads, eliminating the need for rigid stays.
• The divider is adjustable, so the maximum volume of the pack can be adjusted by changing its depth. It can be even opened completely.
• The compartment and side panels are cut to fit the profile of my back, so that the pack sits perfectly right where it should.
• There’s a separate pocket at the top of the pack, with another inner pocket for valuables built into its bottom. The pocket has two zippers, so it can be accessed from both back and front of the pack.
• The only downside of not having access from the top is the loss of the possibility to extend the volume of the pack at its collar. Now there’s much tighter limit on what fits or not.
• The hipbelt is very breathable – one can blow through it easily, and it reduces sweating by a lot. It’s made of a spacer mesh, perforated foam and a strong vinyl-coated mesh on the outside. This is where most weight could be saved if this breathability is sacrificed.

[Eric Blanche]

Good work!

How much did your hip belt weigh in total? Is it sewn in or a sleeve there?

Certainly resembles the Arc blast from zpacks looking at the first pic. :)

 

[Gunnar H]

Inrteresting! I have been thinking of adding some internal straps to achieve similar advantages. So it works well then? Really nice work.

[JCH]

Would love to see more details (and photos) of the vertical divider.

[Lester Moore]

Nice looking pack and design. The center divider is an idea I had for a fast pack to sit closer to the back when fully loaded – glad to see it works on a larger pack too. Great idea on making the divider adjustable to make the pack more versatile at different volumes.

[Jerry Adams]

Good idea and nicely done.

I had a similar idea.  One thing bad was to have two pockets rather than one big pocket.  A little hard to load them and have weight evenly distributed.  Although having the divider on just the top 3/4 helps.

I’ve made a couple versions like this:

Tent poles are on front of pack.  Constrained in a pocket at the bottom, strap at the top.

You get the same effect as having two tubes.  Flattens the pack.  Makes it stiffer.

[David Thomas]

I like it a lot.  As you say – a flatter pack carries better because it’s closer to your back versus one that bulges towards a spherical shape.

A variation I’ve long pondered, specifically for desert trips, is to have two 4-inch-diameter tubes running down each side of the pack, closest to your back, forming two supports akin to the vertical aluminum stays / tubes in a frame pack.  4-inch-diameter so you can put two 2-liter soda bottles in each one.  8 liters of water storage when you need it, and when you don’t, put the empty ones at the bottom to keep the pack’s center of gravity high.

If you had a few staple, bulk items (Ray Jardine and all his cornmeal?  Oatmeal every morning?), you could store it in one of the bottles not used for water.  Or (and this is the first time I’ve considered this) if you modified a 2-liter bottle to be a wide-mouthed bottle with some PETE welding or just cut the bottom 2/3s off of two bottles and jam them together to keep food / sleep items inside of.  For the weight of only a little more fabric and the bottles (48 grams each), you’d get:

-massive water-hauling capacity

-structure for the pack

-more protected (from water and physical damage) volume for food and supplies.

[Jan Rezac]

The divider is a piece of fabrics shaped the same as the side panels, contoured according to my back where it is attached to the back panel. This makes the pack not only flat, but also shaped. The divider is cut in the middle and connected with pieces of webbing at multiple places. This allows changing the volume of the pack, and when disconnected, it makes it possible to turn the pack inside out (what’s useful during the construction).

Using just straps would help flatten a pack, but a solid divider has two important advantages: it allows defining a nice smooth curve of the back, and it provides also diagonal stabilization, so that the pack can maintain it’s shape under higher loads.

I was also considering replacing the divider with a frame made of two solid tubes, one contoured one at the back, and one in front. With that, the same shape of the pack could be achieved without dividing the space, so I would be easier to pack. For the intended use, I decided it was not worth the extra weight and work. What is nice that with such a frame, it would be possible to construct a true panel loader with opening from the front, where the zippered flap would contain the front tube.

[Roger Caffin]

Nice, but I can’t help feeling that it is rather like some of the Aarn packs with that central divider. Differences?

Cheers

[Daryl and Daryl]

I’ve tried each option discussed here except for David’s tube pack.

I’ve also tried a single buckled strap in the center of the pack that connects the front with the back.  Goes a long way toward flattening the pack with minimal interference to packing.    Bottom half of pack can be filled before strap is connected.

My favorite option is Jerry’s external pole compression, however, or nothing at all.  Both options leave the single wide-open bag,  which is easiest to access and load evenly.

[nunatak]

Love it! Like the Giant Jensen

Always wanted to make one like this.

[Jerry Adams]

I like all the good ideas here on BPL. Broader than anything commercially available. Thanks people for posting : )

 

[Graham F]

I am with (retired)jerry, thanks for posting Jan. Would love to see it first hand.

[James Marco]

Yes, that was the name…Jensen. Very similar…
Thanks!

[David Thomas]

The Great Pacific Iron Works (Chouinard before he discover pile and fleece) had a similar two-tube pack but with a bottom compartment in the early 1970’s.  A friend’s widow gave me one that may have gone up Denali and some peaks in the Andes although I’m sure he switched by the time he was on Everest and K2 (where he died with his son).

[Doug Coe]

Jan—I love your innovative thinking! I’m mulling over ideas for a myog pack, and I also would like it to be flat, nor barrel-shaped.

Zpacks has horizontal bars on the outside.  Hanchor’s Marl has one high on the inside—which I imagine does half as good a job as if there were two, top and bottom.

As for the divider, I prefer a big open bag suitable for a bear can.

Great work!

[James Marco]

Yeah, As far as keeping a pack flatter against your back, it IS a good idea.
As far as support, I think the two side loading tubes are good. As was said, balance between the two could be a problem. Hmmm… Great idea, though. And your pack really looks nice, if a little heavy at 22oz.

Loading below with a bear ball is a problem. Even here in the NE we have several areas that require their use. Loading on the top or bottom of the pack will always be a problem, I believe, it sort of breaks up the tubular shape into a more segmented one.

Just a thought, I wonder of some 3mm line and some large (like 3″ diameter) washers might do about the same thing. Two or three lines could be clipped as you load/unload, pulling the center together. In a 22″ pack, say two lines at 8″ and 16″, should allow a standard 9″ bear ball to be put in below with the first line clipped over it and snugged in. Then as you add sleeping bag/sleeping cloths, clip the second line, I think 16″ of 3mm spectra line and 2 fiber washers would be about the same weight as the partition and stitching…likely easier to manufacture, also. Just a thought…likely you would need something to hold the washers on…

Anyway, Good Job!

[Scott Nelson]

I found an old book at the library about making your own lightweight backpacking gear by Vick Hines (who sometimes is on BPL).  I used the plans in the book to make a soft pack inspired by the old Jensen pack. I recently sold it on BPL but it was an interesting project.  It was a challenge to sew all the vertical and horizontal dividers.  The vertical divider did not come too high, so a bear can could still squeeze in on top, within the pack.  It was a challenge to pack but carried well. It really was shaped in 3 dimensions to fit you.

I have also thought of sewing a vertical divider that was parallel to the back panel but say 2” way.  I wonder if you could stuff your sleeping bag and clothes in this section to make it stiff and “framelike”?  At least nothing would be poking your back.  There was a Kelty daypack like that back in the 70’s with a side zipper to access it.

Scott

(oh and there is a Chouinard pack on eBay asking for $1000)

[William N]

Jan, Great pack. Well thought out.  What I think is really good information is that you try something, find a short coming and then try something else.

[David Chenault]

Jan, that thing is frickin awesome. Very aesthetic, too.

I’ve long been tempted to make a Jenson clone but resisted because I assumed the packing limitation, especially with bulky stuff like technical gear, would be too acute. Your pack has me thinking I ought to try it out anyway.

[Nick Gatel]

[Doug Coe]

@zkoumal Jan—Do you find rain gets in the long zippers on the sides? Did you consider using water-resistant zippers?

I’m curious since I’m going to use a vertical zipper in my MYOG pack project.

[Jan Rezac]

@sierradoug The side zippers are of course a potential leak, but I use a poncho most of the time so it’s not an issue (and I’d use a pack cover otherwise). I opted for normal zippers mainly because they run smoother. I’d be also worried of the long-term durability of the coated zippers.

 

[Jerry Adams]

That’s sad

I got rid of my old Kelty when I moved, too much junk.  Lot’s of great trips with that pack.

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