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Reviews > Packs > Frameless Backpacks and Day Packs > Gregory Z25 & Jade Day Pack > Test Report by David Wilkes

Test series by David Wilkes

Gregory z25 Day Pack

Initial Report - Jan 06 2008
Field Report - April 07 2009
Long Term Report - June 09 2009

David Wilkes


Tester Information

Name: David Wilkes
Age: 42
Location: Yakima Washington USA
Gender: M
Height: 5'11" (1.80 m)
Weight: 197 lb (89.40 kg)
Torso: 19"( cm)


I started backpacking in 1995 when I moved to Washington State. Since then, I have backpacked in all seasons and conditions. I have usually only managed time for 1-3 trips a year averaging 2-5 days, and as many day hikes as I can. I am currently getting into condition to summit some of the higher peaks in Washington, Oregon, and California. 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. My current pack is around 30 lbs (14 kg), not including consumables.

Product Information


Gregory Mountain Products

Year of Manufacture:


Manufacturer’s Website:


Not Available (from manufacturer)
Listed Weight: 2 lbs 14 oz / 1.30 kg (Medium)
Measured Weight: 2 lbs 14 oz / 1.30 kg
SIZE: Medium (Torso Lenght 18-20 in /  46-51 cm)
Volume: 1525 cu in / 25 L

Product Images
Images courtesy of Gregory Mountain Products

Product Description:
The Gregory z25 is described by the manufacturer as an ultra light technical daypack.


  • JetStream™ DTS Suspension   
  • Auto-Fit harness system
  • Dual hydration ports and sleeve
  • Top stash pocket
  • Expandable front pouch
  • Side and bottom compression
  • Quick access waistbelt pockets
  • Side mesh pockets with compression pass-through
  • Dual axe/tool attachment points
  • Interior organization pocket
  • 210d double box ripstop and broken twill nylon fabrics

Initial Report

Size Volume Weight Torso Length
Small 1525 cu in
25 L 
2 lbs 12 oz
1.25 kg
16-18 in
 41-46 cm
Medium 1525 cu in
25 L
2 lbs 14 oz
 1.30 kg
18-20 in
46-51 cm
Large 1650 cu in
 27 L
3 lbs
 1.36 kg
20-22 in
51-56 cm

The manufacturer refers to this as “the sweetest daypack you will ever wear” and goes on to describe the pack as an ultra light pack with a suspension system designed to automatically adjust according to the load (up to about 35 lbs / 16 kg)  and allows your back to ventilate in warmer temperatures.

With one exception noted below, it appears that no feature or detail was overlooked during the design and construction of this pack.

The pack is offered in 3 sizes (I received the Medium size). 
The pack also comes in 3 colors: Moroccan Blue, Onyx (Black), & Siberian Green (I received the Blue).

Waistbelt storage Pocket
Waistbelt storage Pocket

I am not entirely sure I would classify 3 lbs (1.36 kg) for a 25 L pack as “ultra light” in and of itself. There are a number of similar volume packs on the market that are significantly lighter than this one, but I must note I have not found any of these to have features comparable to the z25. If it is in reference to the “light” style of backpacking where one typically carries a full loaded pack of 20 lbs (9 kg) or less, then I would say this pack could fall under that category. I do not personally practice light or ultra light backpacking, but I do continually strive to lighten my load. While examining the way this pack is designed and constructed, I find myself contemplating the possibility of an overnight trip in warm weather with this pack. Unfortunately, I do not expect to encounter weather in my area favorable to attempting that until long after this test series is completed.

I hardly know where to start; this pack seems to have features and notable details every place I look.
One feature that I often look for in packs, but rarely find is storage pockets on the hip belt. I find these a convent place to store small items that I like to keep at hand, such as bug repellent, sunscreen, lip balm, camera, GPS, snacks, etc. There are a number of aftermarket products that can add this capability, but I find they rarely attach securely, and often can interfere with movement. The waistbelt pockets on this pack look to be well made and conveniently placed. They are big enough to hold some basic items like snack bars and lip balm, or even my camera or GPS. Since the hip belt pockets are made of mesh with a fabric lid, they should not collect water and it should be easy to locate some of the smaller items that I might store in them. On the other hand, since they are not waterproof I will need to be careful what I store in them if I anticipate rain or snow.
I primarily use a hydration bladder when hiking, and have developed a few preferred configurations. The z25 contains a sleeve for holding a hydration bladder, and 3 hook-n-loop tabs for securing the bladder in place. My 2 L (72 oz) bladder fits into the packs hydration sleeve as if they were made for each other. There is an opening at the top of the pack directly adjacent to a small storage pocket, for the water hose. The product specifications states “dual hydration ports”, but I have been able to locate only one.

Stash Pocket and Hydration Port
Stash Pocket and Hydration Port
Stash pocket alternate view

The hydration port is the one feature of the pack that does not appear to me to be fully thought out. The stash pocket is located such that it hangs inside the pack in front of or inside the hydration bladder pouch; however, the opening for the water hose is in front of the pouch. The result is that the hose has to wrap around the pouch if it is in front of the bladder, or the pouch must be tucked behind the bladder. With the pouch behind the bladder, it blocks the three securing straps. The hose then passes out of the hydration port in front of and then across the zipper opening of the stash pouch, thereby further blocking an already tight opening. I am not entirely clear as to the intent of the top pocket. I am unable to reach the pouch while wearing the pack, and even with the pack off, the opening is so tight that only with much effort am I able to reach my hand all the way into the bottom of the pouch. The size and position of this pouch look as if it might be meant to be used only without a hydration bladder. I tried filling the pocket with items that I do not use often (first aid kit, blister kit, space blanket, fire starter, etc) and found it did not work well when my hydration bladder was installed.

The pack has stretch side pockets that allow access to items like water bottles without removing the pack. I tried this with my 1 L (32 oz) and 0.5 L (16 oz) water bottles and had no trouble removing and replacing it in the pockets. The material the pockets are made from have quite a bit of stretch and I was able to fit a water bottle along with a small plastic garbage bag and a few energy bars in one. The lower compression straps pass through the side pockets allowing the pockets to be used without interfering with the compression straps. Alternately, the straps could be put around an item that sticks out of the pack to keep it secure. The side pockets are large and have enough stretch to accommodate my water filter, with room to spare.

On the front of the pack is a large expandable front pouch. My SnowClaw snow shovel fit perfectly, and it has enough stretch to also fit my rain gear or a fleece jacket.

The dual tool attachment points are well located and provide secure storage for my trekking poles or ice axe.

The main compartment of the pack is accessed via a double zipper that extends at least two-thirds the length of the pack. When fully opened, everything inside the pack is easily accessed. At the top of the inside front of the pack is a large mesh inner storage pocket. Inside this pocket, a small plastic clip is attached to one side for attaching items like a key ring.

There are 6 compression straps on the pack. Their location and range of adjustment look like they will allow me to use the pack for a wide range of conditions. For smaller volume loads, the bottom straps can be cinched in to help keep the weight higher and closer to the small of my back for greater stability.


jetstream dts illustration
Image courtesy of Gregory Mountain Products
The manufacturer states that the “JetStream DTS” suspension system is a lighter weight version of the JetStream LTS” suspension system used in the larger versions of this pack. The suspension is based upon a spring steel bar formed into a loop to form the frame of the pack and keep tension in the mesh back sheet. This maintains an air space between the pack and stiffens as the load in the pack increases. The hip belt, lumbar pad, and shoulder harnesses strike me as something fit for a much larger, multi daypack, with lots of padding and contoured to wrap around the body.

The pack arrived with little in the way of instructions. The product brochure and the tag attached to the pack contained some basic descriptions of the major features and some specifications as well as instructions on how I should measure my Torso length to ensure I get the right size. I measured my torso length according to the instructions and my torso length (19 in /48 cm) makes me a medium. The instructions go on to state that for torso lengths that fall between two sizes to go with the smaller size.

Gregory offers the original purchaser a lifetime guarantee against defects in materials or workmanship. They also offer to repair, “for a reasonable charge plus shipping and handling”, any wear or damage not covered by the warranty.

Manufacturer's Web Page:
I found the web site simple to navigate. Along with basic images, features and specifications for the product the site includes a link to a document on how to properly fit and adjust their packs. Their website also includes links under Customer Support on how to care for their packs as well as instructions on proper loading of a backpack.

One oddity is that I was unable to locate the z25 on their “Men’s” product page. I found it necessary to go to the generic “Products” page find the z25 (as well as the woman’s version “jade 25”) packs.

Sternum Strap Detail
Sternum Strap
Initial Fit:
The pack arrived with all of the adjustments pulled to their smallest sizes. As I do with all packs, I extended all of the fit adjustments to almost their largest length and put the pack on (after partially filling it with gear). I tightened the shoulder straps followed by the waistbelt. I then tightened the load lifter straps and finally the two stabilizer straps on either side of the waistbelt. I then adjusted the sternum strap down to a comfortable position, snapped it closed and adjusted it.

The pack felt amazingly light and comfortable. I had a full 2 L (72 oz) water bladder, a jacket, rain pants, along with basic hiking supplies (first aid kit and basic emergency supplies) inside the pack and a 0.5 L (16 oz) water bottle in one of the side pockets. I jumped up and down, twisted from side to side and bent in different directions, but the pack stayed in place with little or no shifting. Since I recently broke a bone in my hand during a fall that was at least partially due to my pack shifting, I was impressed by the stability of the pack after only rudimentary adjustments. I look forward to seeing how this pack performs on the trail with actual loads.

The way the sternum strap attaches to the shoulder straps is something entirely new to me. There is a bead of material running down and following the contour of the lower two thirds of the shoulder straps. The sternum strap connects to the shoulder straps by way of a piece of plastic that is snapped onto the bead of material and can be adjusted up and down along the length of the bead. This is a clean looking design and I like it. However I couldn’t help but wonder what it would take the plastic piece to come off the bead, and if it does if it would be possible to reattach it. I tried pulling (hard) and twisting the plastic piece and it looks like it is on quite securely.

The location and configuration of the waistbelt adjustment make it very easy to adjust while wearing the pack. In addition, there are small elastic bands around the web waistbelt straps to secure the loose end of the belt. I hate having dangling straps brushing against my skin while hiking, so I really like this detail. The chest straps have this same sort of elastic band to retain the loose end of the straps.

Overall construction and materials:
While examining the pack I could find no flaws or indications of deficiencies in workmanship. The pack looks and feels like a high quality and durable product. All of the plastic buckles and clips look to be of very high quality.

Side Detail
Side Detail
Back Detail
Back Detail

Field Report

UsageUsing the pack on a day hike
Two day hikes in the Oak Creek Wildlife Area
    Air temperatures were a bit below freezing, and the weather was mostly sunny with calm winds. The trail was mostly packed snow and quite icy. The first trip I was with my daughter and the second by myself. On the second trip, I maintained a brisk pace and as a result slipped on the ice a few times. I also did a bit of bouldering on an exposed section of rock to see how stable the pack was and if it would interfere with movement.
On both trips and most subsequent trips (see details below) I carried my basic hiking gear (first aid, emergency equipment, and rain jacket/paints) weighing around 7 lbs (3 kg) not counting water. I also carried a full 2 L (64 oz) hydration pouch and two 0.5 L (16 oz) water bottles.

Day hike into Umptamum Creek Falls - Washington
    Again, the trail was quite icy and a few spots were a bit dangerous. We hiked to the falls and I did a bit of exploring in and around the rocks above the falls while my daughter watched two groups of climbers (one on the rock face and one climbing a frozen waterfall). I was carrying the same equipment as above.

‘Urban’ Day hike Yakima Washington

    I spend a few hours hiking from my house into and around town, with the same gear as above, but no water.

Two days snowboarding in Loveland Colorado
    Temperatures were way below freezing with fresh powder as well as groomed trails. I carried only extra clothing, a water bottle and some snacks in the pack. I am a terrible snowboarder, and as a result had more than a few wipeouts.

Day Hike up Umptanum Creek Washington

    The temperature was 45 F (7 C) with a slight breeze when I started out. I fallowed the creek up the canyon for a few miles, but the trail was washed out and I could not find an easy place to cross. I ended up exploring some of the side canyons doing some scrambling up loose talus and mud slopes and up a few slippery rock faces before exploring the cliff tops and then negotiating my way back down following some game trails where I could find them. By the time I returned to the trailhead, it had warmed up to 50 F (10 C) and it was raining lightly. I was carrying the same basic equipment as my first hike except that my water bottles and bladder were empty (I filled them from a stream about half way through the hike). In addition, I was carrying my rain gear.

Day hike to Switzer Falls in the Angeles Crest National Forest California
    I hiked in to the falls with my two girls, my wife, and my wife’s aunt. I played ‘Sherpa’ for the group carrying water snacks and even my wife’s purse in the Z25. The day started out cool but warmed up to around 70F (21C) by the afternoon.

Emergency gear pack in my work vehicle
    During the testing, I have used the Z25 to hold the ‘emergency’ gear that I carry in my work vehicle. This consists of the same basic gear I carry for day hikes plus a stove, food, and tea/coffee. I usually toss the bag into the back seat, but sometimes need the room and so the bag will be tossed (and I mean ‘tossed’ literally) into the back of the vehicle on top of all my equipment.

Mountain Bike ride
    I just purchased a new mountain bike, and took the pack with me on a short evening ride (some dirt, but mostly paved road). I was carrying the same gear as the hikes above, but with only a single 0.5 L (16 oz) water bottle.

Field Performance and observations 
The Pack seems quite well constructed; however, there is one aspect of the pack that concerns me (but only slightly). I do not know if this is an issue with the design, or the manufacture of my individual pack, but I notice that when I have the pack even partially filled it is necessary to use two hands to fully zip the main compartment. The way the weight of the pack is distributed, the two parts of the main compartment pull apart requiring me to use two hands in order to get both the zippers to meet at the top of the pack. You can kind of see this in the image above labeled “Stash Pocket and Hydration Port.” It is not that it takes strength, but I find it necessary to take the strain off the top part of the zipper in order to get the zipper past that section. I notice that when fully zipped there is an uneven strain on the zipper with most of the force concentrated on the top center of the zipper. My concern is that when fully loaded with bulky items this strain could eventually damage the zipper or pull apart the stitching. Should this zipper fail, there would be little to hold the pack closed aside from the two top compression straps. So far, the construction of the pack suggests that it is well constructed and I see no indication that any of the materials or stitching might fail, so I will keep a close eye on this area.
Using the pack on a day hike
One thing that keeps striking me about the pack is how much of the internal space can be difficult to utilize when using a full water bladder. The bladder pouch hangs in the center of the pack attached near the top. When the bladder is full it divides the pack into four distinct areas.
1) The space below the pouch – widest part of the remaining space and good for larger items that are not flexible (e.g. my Jet Boil stove) or sharp items that might puncture the bladder. It is about the only place internally I would trust to store Crampons if I was also using a water bladder.
2&3) The two sides of the bladder – Long and narrow spaces.
4) The expandable space between the bladder and the front of the pack.
Of these the most difficult to utilize is the space is the space between the bladder and the front of the pack. When fully zipped this has the potential to hold a significant volume of gear. It is partially taken up by the interior organization pocket and the top stash pocket, and anything you put in this area will be compressed directly against the bladder so I don’t like to put anything that has the potential to be crushed or could puncture the bladder. Finally, the way the way the main compartment opens with the main zipper, while it makes accessing everything in the pack simple, means that anything in this area will come out when the pack is opened. So far, the only use I have made of this area is to store clothing such as rain gear, extra jacket, etc. All that being said, I can think of no better configuration for this feature in a pack of this size. Therefore, this is more for information than any sort of negative commentary on the Z25.

The comfort and stability of the pack continues to be remarkable. For my first few hikes with the pack, I simply tossed my gear into it with little thought of balance or stability. I placed small heavy items in the stash and organization pockets and the rest of my gear just tossed into the main pouch. I made almost no effort to adjust the stabilization straps or compression straps. However despite hiking on slippery icy trails, and intentional twists and bends (to see if the pack would move or shift), the pack remained stable. Remarkably, after my second hike I returned and noticed that prior to the hike I had disconnected one of the stabilization straps from the waste belt prior to the hike and forgot to reattach it. Despite this, the pack was stable and did not shift. While snowboarding, the stability of the pack was outstanding. Despite some spectacular crashes (I am new to snowboarding and really SUCK), the pack remained in place and I could easily forget I was wearing it. On my hike back from Switzer Falls I worked up a bit of a sweat. However, the mesh back panel did a fine job of keeping my back almost as cool as the rest of my body.

I have found the torso length of the pack to fit me quite comfortably; however, as with most packs, I find the chest harness to be a bit short. Note in the picture at the top and bottom of this Field Report section, how high the sternum strap is, and this is with it at its lowest position. Since I have this issue with most packs I have worn, I expect this is an issue with my body type, and since the pack rides so well and remains comfortable, it is more of an aesthetic issue (in some of the pictures I think I look a little silly) than anything else.

I am finding the expandable side pouches are very well positioned, and I have no difficulties accessing or replacing my water bottles. I have tried .5 L & 1 L (16 oz & 32 oz) bottles of various shapes and they all work well. Getting smaller items like a snack bar or my gloves can be difficult and I find it easier to remove the pack to access these. While snowboarding I placed a 0.5 L (16 oz) water bottle in one side pocket and attached it with a carabiner to the lower compression strap. While the bottle did slip out of the pocket a few times it only came entirely loose once, and I believe that was the fault of the cheep carabiner I was using. The size of the pouches and amount they stretch allows me to put quit a few things in them besides my water bottles.

The waistbelt pockets are very handy. I find I can put my camera with my SticPic (camera mount for my trekking poles) attached, or my Garmin GPS in one with room to spare, and I have had two energy bars & three Goo packs in the other.

So far, I have not really tested the pack with a full load. I am finding that even with a full water pouch, this pack has more than enough room for everything I normally take on a day hike plus some extras. During the testing, I have made it a point of carrying more water then I normally would, as well as tossing in an extra layer or raingear even if I doubt I will need them. Even with the extra weight added to the relatively high weight of the pack, I have been very pleased with the comfort of this pack. I have been toying with the possibility of replacing my tent/bivi with a hammock, and if I do go in that direction, I am contemplating a short summer solo backpacking trip using this pack. Unfortunately, conditions in my area will not be favorable to this until long after this testing is complete.

Bridge crossingDurability
The pack seems to be quite durable. During my field testing the pack it has endured being tossed in the back of my truck, dropped on snow, dirt and rocky ground, it even withstood some embarrassing head-over-heel tumbles (that my brother and nephew found hilarious) while snowboarding. While trying to help my daughter learn to snowboard she managed to snag the straps on my pack a few times with her bindings. I fully expected to find at least one of the straps ripped or at least showing some sign of the abuse, but I was quite surprised to find no damage to the pack.

So far, I am quite pleased with the Gregory pack. While it is heavier than some other packs available, I feel its features, comfort, stability and quality more than make up for the additional weight. While I like to use a hydration bladder, I am finding the pack is much easer to load and organize without it. The hydration bladder pouch can then be used to better organize the contents. And without the bladder in the center, the pack is simply HUGE. It has room for all my gear and more. So far I have not come close to fully filling it. The Z25 is in my opinion living up to the “sweetest day pack you will ever wear” claim. At least it is the sweetest daypack I have worn so far. I have only one real complaint with the design of the pack, that is with the placement of the top storage compartment in relation to the hydration tube opening, and even that is a rather minor issue.
Overall I have enjoyed testing this pack and fully intend to use it as my primary daypack for the foreseeable future. I would confidently  recommend this pack to friends and family.

Long Term Report

Long Term Usage:Wearing the Gregory Z25 on a hike in Western Washington
  • 3-4 Road/Trail bike rides
  • 2 Day hikes to the park with my kids
  • 1 Day hike above Lake Sabrina (California – Eastern Sierras)
  • 1 Day hike (Ohanapecosh Hot Springs) with my daughter’s 6th grade class
  • Continued use to hold basic safety/comfort gear in my work vehicle
The Long Term Testing did little more than support my findings in the Field Tests. The pack continues to be incredibly comfortable and stable, with more volume than I need (a good thing, vs. not enough space).

As in my field testing, I quickly forget I am wearing the pack as it rides so well and never shifts regardless of what I am doing (hopping across rocks, mountain biking, playing with my kids in the park, etc). As noted in my initial report, the pack is a bit heavy when compared to other day packs on the market of similar volume, but its features, stability, and comfort more than make up for the weight in my opinion.

I have yet to really fill the pack, and am amazed that the pack can hold such a large volume while still being stable and comfortable even with a low volume dense load (such as lunch, water and basic safety gear).

On one hike the stability of the pack may have made a huge difference in my ability to assist my father-in-law. While crossing an icy stream, my father-in-law slipped, fell, and was unable to get back up due to the rocks and fast running water. I quickly spun around and leaped into the stream to try to help him. At the time I was carrying all the gear for both of us including our lunch and a bottle of wine (no bottle, the wine was in a PlatyPreserve), and I had made no effort to properly pack the items (this pack has spoiled me, and I fear I am picking up some bad habits). At the time I was totally focused on seeing if he was hurt and helping him out of the icy water. If the pack shifted I could easily have lost my balance as well. As it turns out the pack was stable and caused me no difficulties at all. In addition I was able to place his wet jacket in the expandable front pouch, thereby keeping the rest of our gear dry.

So far the temperatures during my hikes have ranged from very cold to comfortable, so I have not had the opportunity to fully test the packs ability to keep my back cool.

The versatility of this pack is remarkable. On solo hikes or when I am carrying smaller volume loads the ability to utilize my hydration pouch is very nice. On the other hand when I have higher volume loads or want more internal pack space to better organize my gear I have really enjoyed using the external side pockets to hold my water bottles, and the way the compression straps pass through/across these pockets makes it easy to secure the bottles. I use a carabineer to attach one of my water bottles, and tighten the straps across the neck of some other bottles.

The pack has held up quite well despite being tossed into the back of my truck and Explorer fully loaded and repeatedly placed on dirty rocky ground. I have found no signs of wear. All of the stitching, zippers and straps look to be as secure as when I received it. The zipper for the main compartment has held up quite well despite my initial concerns about the strain not being evenly distributed along it.

I fully intend to continue to use the Z25 as my primary day pack for hikes, biking, and general day to day use. Aside from the size and placement of the top stash pocket (noted in the previous reports) I can find nothing wrong with the pack, and just about nothing more I could want in a day pack. As I mentioned in the start of my Initial Report the manufacturer bills this as “the sweetest daypack you will ever wear”, and while I can not say it is the best pack I WILL ever wear, I can state with confidence that it is the best day pack I HAVE worn so far.

This concludes my Long Term Report. I would like to thank the folks at Gregory Mountain Products and for the opportunity to test this fine product.


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

Reviews > Packs > Frameless Backpacks and Day Packs > Gregory Z25 & Jade Day Pack > Test Report by David Wilkes

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