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ZPacks Dyneema X 26 Backpack Review

ZPacks offers a range of pack sizes, fabrics, and innovative pack options that minimize weight. You end up with a really lightweight custom pack. How does the tested ZPacks Dyneema X 26 compare to other lightweight frameless packs for ultralight backpacking?


Overall Rating: Recommended

Although the Dyneema X 26 is delightfully light, durable, strongly constructed, and has lots of available options, our rating is constrained by the pack’s excess volume beyond the specification, compounded by a weak compression system to reduce pack volume.

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by Will Rietveld |


The ZPacks Dyneema X 26 frameless backpack and its cousins are as close to a custom frameless pack as it gets. The same pack design is available in either Cuben Fiber or Dyneema X fabric and in three volume sizes. You can specify the torso length and choose from a long list of options, so you end up with a lightweight pack customized to your needs and preferences. Of course you pay for the extras. ZPacks owner Joe Valesko is a thru-hiker himself and has an innovative way of keeping the options light. How does the tested ZPacks Dyneema X 26 compare to other lightweight frameless packs for ultralight backpacking?

ZPacks Dyneema X 26 Backpack Review - 1
The ZPacks Dyneema X 26 pack carrying 21.5 pounds on an early spring backpacking trip in southeastern Utah canyon country. The base weight of the pack is 11.8 ounces; you can choose from a wide range of options to customize it as you wish.


Year/Model 2010 ZPacks Dyneema X 26
Style Top loading frameless backpack, drawcord closure with top compression cord; removable stays available
Volume Size Large tested.
Specified volume: 2600 cubic inches (43 L)
Measured volume: 3300 cubic inches (54 L) including pockets and extension collar
Weight Measured weight: 17.2 oz (488 g) with options
Manufacturer specification for base pack: 11.8 oz (335 g)
Sizes Available Unisex S,M,L
Fabrics Pack body and side pockets are 210d 4.2 oz/yd2 (142 g/m2) Dyneema X ripstop, front pocket is mesh
Features Padded hipbelt and shoulder straps, large front mesh pocket with elastic binding, 2 side Dyneema ripstop pockets with elastic binding, sternum strap, 2 elastic compression straps each side, 12 in (30 cm) extension collar, drawcord closure and top compression cord, loops for front bungie system, haul loop
Options Added Top side mesh pocket, middle side straps, removable carbon fiber stays, backpanel pad sleeve, hipbelt pouches, shoulder strap pouch; total weight of added options 5.5 oz (156 g)
Volume to Weight Ratio 206 in3/oz (based on 3300 in3 and measured weight of 16 oz (size Large without stays)
Maximum Comfortable Load Carrying Capacity 25 lb (11.3 kg) estimated comfortable load for an average person carrying the pack all day
Carry Load to Pack Weight Ratio 23.1 (based on 25 lb and a measured weight of 1.08 lb with stays)
Options Hipbelt pouches, shoulder pouch, middle side straps, top lid, top side pockets, bungie system, sleeping pad sleeves, base straps, ice axe loops, hydration sleeve and port, load lifters, external carbon fiber stays, sleeping pad shock cord, pack cover, pack cover pocket


Like several other packs in this frameless backpack roundup, the measured volume of the ZPacks Dyneema X 26 differs significantly from its specified volume. I measured the volume, including all pockets and extension collar, at 3300 cubic inches (54 L), which is 700 cubic inches (11.5 L) more than its specified 2600 cubic inches (43 L). It is customary to include the volume of all pockets and the extension collar in the total volume of frameless backpacks, and itemize the component volumes for user information. I did not include the volume of the optional top side pocket on my test pack.

ZPacks Dyneema X 26 Backpack Review - 2
Views of the ZPacks Dyneema X 26 pack: The front of the pack (far left) has a large stretch mesh pocket that holds a lot of gear. The backpanel (second photo) on my test pack has an optional sleeve for s sleeping pad. Each side of the pack (third photo) has a fabric pocket with an elastic binding. The upper mesh pocket is an option. The drawcord and rolltop closure on the top of the pack (far right) is held in place by a simple cord and LineLok tightener.

ZPacks Dyneema X 26 Backpack Review - 3
Suspension system: padded shoulder straps (left) are 2.75 inches (7 cm) wide. External carbon fiber stays (right) are another option on the pack; they add only 1.5 ounces (42.5 g) to the weight of the pack.

ZPacks Dyneema X 26 Backpack Review - 4
Features: The pack’s front mesh pocket (left) stretches out to hold a lot of gear. The upper side mesh pocket is an option. ZPacks offers unique hipbelt pouches (center) as an option; they have a drawcord closure. An inflatable sleeping pad in the optional backpanel pad sleeve (right) is very comfortable against the back.


ZPacks Dyneema X 26 Backpack Review - 5
I tested the Dyneema X 26 pack on several late fall and early spring backpacking trips. Here I carried 21.5 pounds (9.8 kg) on a four-day March backpacking trip in southern Utah.

In the pack load carrying capacity tests we conducted as part of our Frameless Backpacks State of the Market Report 2011, the Dyneema X 26 was comfortable to about 18 pounds (8.2 kg) without stays and to about 20 pounds (9.1 kg) with stays. The stays did not make much difference. The heaviest load I carried in the pack on a backpacking trip was 21.5 pounds (9.8 kg), with a folded inflatable sleeping pad in the pad sleeve, and the pack carried the load quite well. On the same trip, the pack had plenty of room for gear plus expendables, and enough room left over for another four days' travel, so the extra volume is evident.

The pack fits me quite well; note in the photos that the shoulder straps are level with my shoulders. My torso length is 20.5 inches (52 cm) and the measured pack torso length is 19 inches (48 cm) by the BPL method (inside of shoulder strap to middle of hipbelt), and 20.5 (52 cm) by the conventional manufacturer method (top of shoulder strap to bottom of hipbelt).

While ZPacks’ features and options are lightweight, they are not high functioning. The side elastic compression cords do not compress the pack very well, resulting in only 32% volume reduction, which is the second lowest in the group of packs I tested. The top compression cord uses a LineLok connector to hold it tight, and the arrangement works very well. The external carbon fiber stays are very lightweight and convenient to insert/remove, but they do not provide as much support as stays on the inside of the backpanel provide on other packs. The add-on mesh side pocket seems quite vulnerable to snagging, but it did survive quite a bit of brush bashing on my trips; I would prefer a Dyneema ripstop pocket to match the other side pockets. The backpanel sleeping pad sleeve is made of Dyneema ripstop fabric, and works just fine, but it seems like a stretchy mesh sleeve would be better. Finally, ZPacks’ hipbelt pouches - essentially a stuff sack - function well and hold a lot, but I would prefer zippered pockets for easier access.


Comparative specifications can be found in my Frameless Backpack State of the Market Report 2011 Part 3. The closest comparisons are the Ultralight Adventure Equipment (ULA) CDT, Hyperlite Mountain Gear Windrider, Gossamer Gear Gorilla, and Mountain Laurel Designs Prophet.


The ZPacks Dyneema X 26 is a good pack choice for shorter ultralight trips, or longer trips if you have a low volume gear kit. Dyneema ripstop fabric is an excellent balance of durability, light weight, longevity, and cost. The same pack can be constructed of Cuben Fiber at a similar cost, but you only save 4.4 ounces (125 g) and Cuben Fiber has a limited lifespan. ZPacks’ long list of options is another plus, but it requires you to make a number of decisions. My advice is to choose carefully on the options.

Although ZPacks’ external stays did not add much support in my torso collapse tests, reported in Part 2B of our frameless backpacks state of the market report, they are very lightweight at 1.5 ounces (42.5 g) and they help maintain the pack’s torso length, especially for smaller loads.

For me, the two main shortcomings of the ZPacks Dyneema X 26 packs are: 1) it's oversized, and 2) the compression system does not reduce pack volume very much for smaller loads. I wanted a frameless pack to match the volume of my gear kit plus expendables, but the pack’s extra 700 cubic inches (11.5 L) caused it to be under filled much of the time. On top of that, the pack’s compression system did not function very well to reduce pack volume for smaller loads. Webbing side compression straps would do the job much better than the pack’s elastic cords.

Overall, the Dyneema X 26 is a strongly constructed, durable frameless pack well suited for ultralight backpacking, especially with lighter loads. Unlike many other packs, this one can be customized with options to meet nearly all of the user’s needs and preferences.

What’s Good
  • Durable fabric
  • Comfortable suspension system
  • Comfortably carries loads less than 25 pounds (11.3 kg)
  • Large stretch nylon front pocket for convenient access to items needed on the trail
  • Fabric side pockets provide more durability for bushwhacking
  • Lots of features and optional accessories
  • Very sturdily built, with adequate reinforcements
  • Fits well (if you choose the correct size)
What’s Not So Good
  • Volume is way over specification
  • Optional stays do not provide much additional support
  • Elastic cord side compression straps do not compress the pack very much
Recommendations For Improvement
  • Accurately state the pack volume, or downsize the pack
  • Use side compression straps, rather than elastic cords, to better compress the pack
Disclosure: The manufacturer provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the manufacturer under the terms of this agreement.


"ZPacks Dyneema X 26 Backpack Review," by Will Rietveld . (ISSN 1537-0364)., 2011-07-19 00:15:00-06.


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ZPacks Dyneema X 26 Backpack Review
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Addie Bedford
(addiebedford) - MLife

Locale: Montana
ZPacks Dyneema X 26 Backpack Review on 07/19/2011 16:01:16 MDT Print View

Companion forum thread to:

ZPacks Dyneema X 26 Backpack Review

Daniel Allen
(Dan_Quixote) - F

Locale: below the mountains (AK)
recommendation for improvement on 07/19/2011 19:16:06 MDT Print View

"Use side compression straps, rather than elastic cords, to better compress the pack"

What if, instead of 'straps', Joe used inelastic cordage, like his z-line or another cord typically used for guylines?

That way, it wouldn't stretch, but would still be sublimely light and take exactly the same amount of work in making the pack. Also, it's mod anybody could do at home.

I'm looking at this pack and thinking that the extra volume would be fine if it had the wrap-around compression options that modern Golite Jams have; what if the guyline cord was strung through the back mesh, though, so the pocket could be filled and accessed even while the main body of the pack was thoroughly compressed on three sides? I haven't many miles of experience with UL packs yet, but that designs seems like money to me.

Warren Greer
(WarrenGreer) - F

Locale: SoCal
Nice review on 07/19/2011 21:33:38 MDT Print View

Will, glad to read in more detail about this pack. It seems you've made some good suggestions to advance this pack. I'm surprised that the carbon rods don't do much for pack collapse. That's the thing that bothers me most about going to a very light pack.

edit: I definitely admire many of Joe's creations and will finally end up with some of his gear some day.

Edited by WarrenGreer on 07/20/2011 20:10:32 MDT.

Jeremy Platt
(jeremy089786) - F

Locale: Sydney
compression straps optional on 07/19/2011 23:54:09 MDT Print View

I have a blast 26 with inelastic compression straps which worked really well until I decided to switch to the'cloud method' endorsed by Mike C. Joe did not charge me any extra for this, I just had to ask. Joe will do just about anything to keep his customers happy.

Jarod Fleming
(flemdawg1) - F

Locale: SE US
20 volume? on 07/20/2011 08:18:59 MDT Print View

Did you get a measured volume for the Blast/Dyneema X 20? 54L is alot more pack than I need.

Johan Westring
(Johan) - MLife
cordage on 07/21/2011 09:09:17 MDT Print View

It looks like a great pack. Both of the cons seems like a non issue. With inelastic/elastic cordage on the sides you can be much more flexible backpack. I prefer using cordage that runs from the top to bottom and goes inside the lower pocket. That stabilizes the pack and pushes the center of gravity closer to your back. It will make the backpack feel much lighter.

(cuzzettj) - MLife

Locale: NorCal - South Bay
RE: "ZPacks Dyneema X 26 Backpack Review" on 07/22/2011 23:40:42 MDT Print View

Just playing Devil' advocate here... Too many features on your pack maybe?

A quick clarification. I think, had the pad been used as the frame, you wouldn't have had as many issues with the volume? What do you think? Honestly I want one of his packs and the pad as the frame is my go to method. The benefits seem to out-way the issues. But my son loves his pack that has the same features.

Thanks for the great article. It got me thinking.

Edited by cuzzettj on 07/22/2011 23:47:30 MDT.

Dan Durston
(dandydan) - F

Review on 07/23/2011 11:03:02 MDT Print View

Thanks for the review. These packs are pretty fully featured. I think a lot of people would be better off building up one of Joe's size Medium Zero packs instead (same basic pack) and adding the features they want. This way you don't get features you don't want, and you can opt for a dry bag style roll top to easily reduce volume.