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Reviews > Packs > Frameless Backpacks and Day Packs > Gregory Z35 or J33 day pack > Test Report by David Wilkes

Test series by David Wilkes

Gregory Z35

Initial Report - June 13 2014
Field Report - Due Aug 2014
Long Term Report - Due Oct 15 2014

Tester Information

Name: David Wilkes
Age: 47
Location: Yakima Washington USA
Gender: M
Height: 5'11" (1.80 m)
Weight: 200 lb (90.7 kg)


I started backpacking in 1995 when I moved to Washington State. Since then, I have backpacked in all seasons and conditions the Northwest has to offer.  I prefer trips on rugged trails with plenty of elevation gain. While I continuously strive to lighten my load, comfort and safety are most important to me. I have finally managed to get my basic cold weather pack weight, not including consumables, to under 30 lb (14 kg).

Product Information


Gregory Mountain Products

Year of Manufacture:


Manufacturer’s Website:


US$ 159.00


Listed 1.33 kg / 2 lb 15 oz (Size L) 
Measured 1.53 kg / 3 lb 6 oz (Size L)


M (35L) L (37L)


Storm Black *
Marine Blue
Solar Yellow
Spark Red

Product image
Images courtesy of Gregory Mountain Products

Product Description:

The Gregory Z35 pack is intended to be a lightweight pack with lots of features, and comfortable even with large loads. It is intended to allow the wearer to “push farther and faster than ever.” It has some very interesting features such as ventilated padding and body-hugging form as well as dual access to the main compartment (top loading and clamshell opening) and more. This is advertised as an update to their popular Z line of packs.

Initial Report

June 9 2014

Front ViewFor full disclosure, I had the pleasure of testing the Z25 pack in 2009. It has been my go to day pack ever since, so I am eager to see what they changed, and if those changes are improvements.

Before I get into the long and tedious task of going over the pack's features I want to comment on my initial impressions when I removed it from the packaging. My first thought was that it looks to be a “slick” streamlined pack. The pack has some clean lines to give it a streamlined, finished look. Upon first look there appeared to be few features, but as it turns out there are actually some really nice features, they are just hidden or camouflaged. For example the pack has dual ice axe / trekking pole attachment points, but they are not readily visible. As I started examining the pack it seemed as if every time I turned the pack I would find another surprise, such as the bottom opening clamshell access to the main compartment. This makes it difficult to know where to even start describing its features.

As for features, there are many and rather than tediously going into detail on every feature I will focus on key features that stand out upon initial inspection or are especially significant to me, and leave the others as well as specific details as to their usefulness, function, and value to the field report.

Back ViewHere are the features the manufacturer lists on the website:
* Updated CrossFlo Suspension
* Ventilated EVA foam on hip belt and shoulder harnesses
* Top-loading main compartment with quick-draw top closure and full-body front U-zipper access
* Floating, removable top pocket with zippered pocket and key clip
* Under-lid zippered stash pocket
* Front bucket pocket for quick gear storage
* Two external stretch water bottle pockets
* Dual quick-access waist belt pockets
* Interior hydration sleeve with hose port
* Hideaway ice axe/trekking pole loops
* Side and bottom compression straps
* Quick-attach, integrated color-matched rain cover
* Materials – 210D robic dynagin, 100D robic GR shadowbox, 200D polyester oxford, 265g polyester stretch woven and 190T nylon taffeta

The feature that I found most surprising and intriguing is the bottom opening clamshell access to the main compartment. In addition to being a backpacker I am also a Nordic Ski Patroller. I have spent more time than I care to think about on the side of the trail digging through a top loading pack looking for something specific (why is it that the thing I need always manages to work its way to the bottom of my pack just before I need it?), it was my duties on the ski patrol that really taught me the value of having quick and complete access to my pack contents. It is really bad form to come upon an injury and say “WOW! That is a lot of blood. Can you just hold your hand on there for a while; I know I have some bandages in here someplace.” This pack has a double zipper, each with large, robust zipper pulls, that allow me access to the contents of one side or the other, or by opening both almost completely expose the interior of the main compartment. This is very similar to a feature that is on a pack that is favored by (and specifically designed for) the ski patrol. These zippers look to be sturdy and well built, which is good because a failure of them could really be a problem. I think it is important note that as a back up to these zippers is the bottom compression straps. These look like they could take much of the strain off of the zippers and at least partially hold the pack closed in the event a zipper should fail.

Near the bottom of the pack are the two ice axe loops. Unlike most packs I have had where the loops are sewn in nylon straps, these are thin bungee cord loops. They each have a small nylon tab attached to them to make them easier to grab. I don’t know how strong these are and if they will stand up holding on to a pole or axe during a tumble down a snow slope, but the compact design with minimal exposure when not in use do look like they will reduce the chance of them snagging on brush. I wish I could say getting snagged on brush was more of a problem for me than tumbling down a snow/ice slope, but sadly I take more than my share of spills.

The upper ice axe attachments are also made of thin bungee cord and in addition to the nylon tabs also have a plastic end and a toggle that allow me to adjust the diameter of the loop. This is similar to other packs I have. The exception is that when not in use the Gregory's are almost flush with the pack and very unobtrusive.

Rain CoverThe pack comes with its own rain cover. I have to say a few things about that. First is that I have always wanted a rain cover for my pack. Second is that I tend to be cheap and just have never managed to spend the money when, on the rare occasion when I have needed it, I have had so much success with using just a kitchen trash bag and a bit of duct tape (two things I always have in my pack anyway). So I am kind of excited about finally having a pack with a rain cover. There is a small dedicated pouch for the rain cover. It is easy to identify because the zipper material is red and there is “raincover” printed just above it. It is located just below the hood and under the opening to the bucket pocket. Inside I found the rain cover clipped to a retention strap such that the cover could be put over the pack but could not be blown away. This retention strap is a nice feature. The cover has a grommet on the bottom to act as a drain for any water that does get in. The one thing I find odd is the location of the rain cover pocket. Accessing it looks to require lifting the pack lid as well as loosing if not unclipping the bucket pocket. Personally I think it would make more sense if it was stored in the outer layer of the bucket pocket.

This leads me to something else that I am not sure I fully understand. The bucket pocket exterior is clearly two layers of material suggesting it forms another storage space. At the bottom of the inside of the bucket pocket is a hook and loop opening that gives access between the two layers of the outer section of the bucket pocket. However this opening is only accessible by reaching my arm down into the pocket. I was totally unable to figure out the purpose of this so I contacted the manufacturer and asked. I received a response the next business day. And the answer? It is nothing more than access to install/replace the ice axe loops. I think this is a miss. I would have put the opening near the top of the bucket pocket and use that for storing the rain cover. That way it could be accessed without opening the pack.

Bottom ViewIn examining the pack, I found the “Floating, removable top pocket” must be a mistake. The top pocket is clearly sewn into the pack and not removable. The lid it does have two separate zippers/compartments. The larger section, accessible from the exterior, nice for those small items I may need access to while on the trail, and a smaller one under the lid, nice for those small  items (like car keys?) I may not need access to but REALLY don’t want to lose. The smaller pocket includes an attached small clip to doubly secure those oh, so precious car keys. (It is obvious I have arrived at the trailhead and spent some fearful moments franticly digging around for my keys while silently praying I did not lose them?)

The pack straps and hip belt are contoured and mostly covered with mesh material and much of the foam padding has diamond shaped perforations to make it more breathable. It is clear the focus was on minimizing weight while making it a comfortable and breathable as possible. The two hip belt pockets are shorter but deeper and wider than the Z25 I tested. These are nylon rather than the mesh used in the previous versions of this pack. I checked and my Garmin GPSmap60 fits, but just barely. It should easily fit small items like a compass, energy bars, sunscreen, camera, etc.

Side View3The pack gets its structure from the trampoline style back, with the tension necessary for the trampoline created by a loop of heavy gauge wire. This creates an air gap between my back and the pack and as I found with the Z25 can also be a convent spot for quickly stuffing something like a jacket or rain shell. The pack also has 4 compression straps, two on the bottom and two near the top. When fully tightened they reduce the pack volume to just about nothing. With them fully extended I was able to stuff about everything I would need for a light, warm weather overnight trip, so I should be able to carry a wide range of loads from the full 37 L all the way down to maybe just a hydration bladder, potentially making this a very versatile pack.

Finally as with most packs this has two stretchable water bottle pockets. In keeping with the streamline theme of this pack, they each have a nylon loop for securing my water bottle, but it is attached so that it is inside the pocket and not visible until pulled out for use.

As I always do, I went over every part of the pack looking at every part, seam, and stitch to see if there are any indications of weakness, or possible flaws in construction. I found no imperfections.

Hip Belt PocketInitial fitting: I have learned that my torso size is normally a large or medium depending on the manufacturer, but being as I more on the thick side (yeah, OK…I am fat) I find that when size guides suggest I am a medium in torso length, then the pack straps tend to be too short and ride too high on my chest. So for this pack I ordered a size large. When I put the pack on, empty, I found the shoulder straps to fit me very well. I quickly adjusted the shoulder straps and hip belt to get a good fit. I then played with the load straps on the top of the pack and found them easy to locate and adjust. Same for the load straps on the sides of the hip belt. I know from experience I will be adjusting these based upon the contents of my pack, so I wanted to know in advance how easy/difficult they are to locate and adjust while wearing the pack. As a test I assembled the gear for a minimalist warm weather overnight trip jut to see how much I could stuff into it and how it fit when full. I learned a few things; my new sleeping bag stuffs down very small, I might be able to use this for an overnight trip, when stuffed full the fit of the pack changed very little.

I have high expectations for Gregory products in general, and except for the few oddities noted above, so far this pack meets or exceeds all of my expectations.

Field Report

Due Aug 2014

Long Term Report

Due Oct 2014

  • Comfortable fit
  •  Wide load range
  •   Integrated rain cover
  •   Bottom opening U shaped access to main compartment
  • Rain cover storage location

This concludes my initial report, I will be posting the fleld report in about 2 months. I would like to thank the folks at Gregory Mountain Products and for the opportunity to test this product.


Read more reviews of Gregory gear
Read more gear reviews by David Wilkes

Reviews > Packs > Frameless Backpacks and Day Packs > Gregory Z35 or J33 day pack > Test Report by David Wilkes

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