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

Gregory Z 35 Backpack
Test Series by Rick Dreher
Long-Term Report

Initial Report - June 13, 2014
Field Report - September 18, 2014
Long-Term Report - November 16, 2014


NAME: Rick Dreher
EMAIL: redbike64(at)hotmail(dot)com
AGE: 60
LOCATION: Northern California
HEIGHT: 6' 0" (1.83 m)
WEIGHT: 175 lb (79.40 kg)
TORSO LENGTH 19.5 in (50 cm)

I enjoy going high and light and frequently take shorter "fast- packing" trips. My longest trips are a week or so. I've lightened my pack load because I enjoy hiking more when toting less, I can go farther and over tougher terrain, and I have cranky ankles. I use trekking poles and generally hike solo or tandem. I've backpacked all over the U.S. West and now primarily hike California's Sierra Nevada. My favorite trips are alpine and include off-trail travel and sleeping in high places. When winter arrives, I head back for snowshoe outings in the white stuff.


Product Info & Specs

The Z 35 is a big, strong daypack, but not heavy.

Product Information

Gregory Z 35

Manufacturer: Gregory Mountain Products

Web site:

MSRP (US): $159

Year of Manufacture: 2014

Size Tested: Medium

Volume (manufacturer): 35 L (2,136 c.i.)

Weight (manufacturer): 44 oz (1.25 kg)

Weight (measured): 49.8 oz (1.41 kg)

Torso Range (manufacturer): 18-20 in. (46-51 cm)

Recommended maximum load: 33 lb (15 kg)

Color: Solar Yellow

Warranty: "Lifetime free from defects in materials or workmanship, for as long as you own it."Ě

Report Date: June 13, 2014

Pack Features

  • 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

Design Evaluation


The Gregory Z 35 is a large, mid-weight, top-loading, perimeter-frame day pack. The main compartment can be accessed beneath the top pocket and via a front zipper, and the pack offers seven external pockets for abundant organizing options. Inside is a reservoir compartment with hose port. The suspension comprises a spring-steel hoop frame with plastic sheet inserts, trampoline-style mesh back panel, and foam-backed hip belt, providing support and load management. A stoawable rain cover and tool loops round out the feature list.


Materials and Construction:

The Z 35 exterior is primarily coated nylon in various weights, with heavier or double fabric used for high-wear areas. The two side pockets are stretch fabric. The back panel is open mesh with some added padded areas. Shoulder straps and hip belt wings are die-cut foam faced with wicking fabric. Webbing, buckles, zippers and related hardware seem selected for light weight, with no obvious "over-engineering." Zippers are standard, not waterproof. Fabric, stitching and seams all look good, with no loose threads, missed stitching or exposed seams and edges (seam edges are bias-taped). Zippers, buckles, and straps all operate smoothly and seem strong and secure. Gregory describes the fabrics as follows: "210D robic dynagin, 100D robic GR shadowbox, 200D polyester oxford, 265g polyester stretch woven and 190T nylon taffeta." I think this means I can shadowbox at the Oxford dynagin.


Main Compartment. As noted earlier, the main compartment is accessed both from the top (beneath the top pocket) and the front, via a U-shaped zipper opening that runs outside the bucket pocket. The main compartment is undivided other than the back reservoir pocket. In this yellow color, the fabric lets plenty of light inside for viewing the contents.

Pockets, Pockets, Pockets. The top lid is also a big pocket (#1). It has a second, flat pocket underneath (#2) with key tether inside. The two stretchy side pockets are #s 3 & 4 and around back, is the large bucket pocket (#5), which is open-top with a buckle closure. Immediately above, another pocket (#6) houses the included rain cover. The rain cover is tethered agains loss but can also be completely removed and left home, freeing its pocket for other uses. It's worth adding the bucket and raincover pockets both have bottom drains, a nice touch. To round out the external pocket census, each hip belt wing has a zipped pocket (#s 6 & 7). As noted, inside the Z 35 is the reservoir pocket (#8) with hose port and reservoir tether above.

Tool Anchors. On either side of the back panel are loops and toggles for securing trekking poles or an ice axe. The familiar webbing loop and strap have been replaced by bungee loops and a toggle locks that basically snap into "parked" position when not used, safe from snagging brush.

Raincover. The raincover is coated nylon and fashioned of a single piece, gathered in the corners to eliminate any seams. It has a single drain hole on the bottom and as noted above, clips to a pocket tether to prevent loss but can also be left home if not needed. Elastic completely encircling the cover holds it in place.

Back panel, Frame and Load Control. The back panel is open mesh, tensioned by the perimeter frame. The shoulder strap yoke is also anchored and tensioned by the frame, creating a dynamic, pre-loaded suspension anchored by the padded waist belt. Flexible plastic sheets provide extra support at the shoulders and lower back. The waist belt and shoulder pad foam is die-cut for ventilation. Two compression straps per side can reduce pack volume and help control the contents and maintain pack stiffness with partial loadsóthey also help protect the main compartment zipper from unwanted strain and opening. Load-control straps connect the shoulder straps to the pack's top, to cinch the frame forward (towards the shoulders).

Documentation and User Guide

The hangtag presents general pack features and specs, in several languages. In addition to description and specifications, the Gregory website has a video covering common features of the extensive Z and J pack series (fitted for men and women, respectively) and individual pages for each pack model, including the Z 35. Other Gregory web resources discuss pack sizing and fitting.

Bureau of Weights and Measures

Sizing & Weight

The Z 35 is available in two size: medium (tested) and large. With no torso length adjustment for fine-tuning, it's a pack that needs to fit correctly off the shelf. This size medium is spec'd for torsos between 18 and 20 inches (46-51 cm), which is where I fall (19.5 in./ 49 cm). The Z 35 measured 18 in. (46 cm) from the shoulder strap attachment point to the bottom of the back panel.

What did it actually weigh?

The pack weighs 49.2 oz (1,412 g) on my scales, complete with raincover, compared to the 44 oz (1,250 g) spec, roughly 10% above spec. The removeable cover itself weights 3.0 oz (85 g).


The very yellow edition of the Z 35 is quite photogenic. Here are some views detailing the pack's design and features.

Reverse view of back panel and suspension.

Main compartment top opening.

Main compartment front zip opening.

Suspension and back panel detail, including steel rod.

Top flap main pocket.

Stretchy side pocket.

Rain cover, tether and storage pocket.

My Thoughts, So Far


The only area where Gregory's specs go astray is in describing the top pocket as floating and removable. It is sewn into place.


Everything about the Z 35 seems quite positiveódesign, features, materials and construction are all top-flight. The suspension looks like it will control varying loads easily and the aggressive back panel ventilation will help in summer's heat. The hybrid main compartment access will be especially welcome for stowing and retrieving camera gear, because I can never guess which gizmo I might need first, when packing. And unlike front-panel only access, I won't ever need to lay it in the snow or mud to get inside. I'm eager to load it up and get going!


Field Locations & Conditions

Have carried the Z 35 perhaps a dozen-and-a-half times since the initial report, both day-hiking and photography trips.

Conditions: My day hikes in the Tahoe Sierra region ranged from 8 to 12 miles (13-19 km). Temperatures were in the 70s to 80s F (21-27 C) and elevations ranged from 7,000 to 9,000 feet (2,140-2,750 m). I used trekking poles. Pack weights were between 10 and 14 pounds (4.5-6.5 kg).

My photo trips were warm to hot, ranging from perhaps 85 to 105 F (29-41 C). Pack weights usually exceeded 20 pounds (9 kg). Most of my walking was urban streets and parks, around various soccer pitches and along riverbank levees, with bushwhacking mixed in. Some levee stretches are riprap, which is basically manmade talus.

Weather: basically sun, sunnier and sunniest. It has rained a total of never during the field report phase and so, the rain cover stayed at home. Fall hopes spring eternal that we'll end our drought and I can yet test that cover during the Long-Term Report phase.

Field Performance

Packing & Retrieval: Packing and unpacking this top-loader is generally easy because the opening is wide enough for large items. Like every top-loader, I sometimes find myself emptying it to dig out the bottom item, but that's just an organizing snafu on my part. Oh, wait, I forgot the front zipper again! Regardless of me being a slow-learner, the front zip opening is great for direct access to gear instead of unloading the pack to get at what's on the bottom. Just need to remember it's there.

Will it all fit?

Yes it does, with room for more.

Day Hikes: Day-hiking with the Z 35 in the Sierra Nevada, the pack carries everything I need for fair-weather trips, and then some. With a big pack, discipline goes out the window and I pack "too much"-- taking the usual "10 essentials" plus lunch plus fishing tackle, camera, binoculars, etc. There is still room. The bucket pocket is nice for the tackle because I can drop the pack, retrieve the gear and dunk a line in minutes. Note: no trout were harmed, harassed or otherwise disturbed during this field test.

Photo Trips: During the field test I most commonly carried photo gear. Along with cameras come accessories, clothing, water, sunscreen, and the like, with loads as much as 20 pounds (9 kg). I start with two cameras mounted with large lenses, both in the main compartment. The cameras are padded with towels or extra clothing so they don't bang together, expensively. Accessories (filters, batteries, tripod mounts, etc.) are organized into the pockets, with bulky items in the big front bucket. Smaller items I want fast access to either go in the front rain-cover pocket or the lid. I still have side pockets for water bottles and the belt pockets for yet other things. I have yet to really stuff the Z 35.

Comfort & Load Control

In all my use the pack has remained comfortable. When carrying large, rigid items like cameras the space between contents and the mesh back panel ensures nothing hits my back; the air gap is wide enough to slide my hand in. The waist belt provides enough support and doesn't dig or slip. The waist straps are much longer than I need and I could trim off quite a bit. I don't often use the sternum strap because the shoulder straps stay in place, not sliding off my shoulders.

Load control is good; if I need to reduce shifting of the contents I can tighten the load-control straps to good effect. This suspension works.

I use a water reservoir for hiking and it stays cool pretty long, perhaps because of the airspace between the pack and my back. Score another point for the suspension. The hose ports and anchors on the shoulder strap worked fine.

The mesh back panel doesn't stop me from sweating but at least I get some circulation and don't have as sopping a shirt as I get with a pack that rides directly on the back. In mid-summer this is a relief.

I bicycled with the pack a few times and it's okay for that, even if the Z 35 is bigger than typical for cycling. The top lid doesn't hit my helmet when I'm leaning forward, which taller packs can. It's far bigger than I need for my daily commute, so I never tried swapping it in for that purpose.


Checking it over, I can't find any wear and tear on the Z 35. The fabrics and stitching are still like new and I'm clearly going to have to try harder bashing it about. I expected the bright yellow fabric to be filthy by now but it retains its original sunny glow. Will add it's really hard to misplace this pack-I can spot it from fifty yards away. That is why I chose it among the color options--hunting season approaches.


The Z 35 has a lot going for it: it's well made, comfortable, holds a lot and controls heavy loads. The suspension and back panel are welcome in hot weather. It works.

Recommendations for Improvement

For my photography I'd welcome strap anchors or a daisy chain that would allow me to lash on a tripod, as the provided anchors are scaled for trekking poles or lightweight tools, such as an ice axe. The Z 35 is a hiking pack, not a photo pack (a vast category in itself) so this isn't a criticism.

As a hiker's pack, so far the Z 35 has been spot on.

Long-Term Report

Field Locations & Conditions

In the last two months Iíve use the Z 35 weekly for a combination of day hikes and photo trips (quite a bit for the kid's soccer season, truth be told).

Even packs get an occasional rest.

Conditions: My day hikes and my photo trips were in my local valley region and the Sierra foothills, and were shorter trips up to 5 miles (8 km). Temperatures were mostly late-summerlike but have recently been cooler, ranging from a high of the mid-90s down to about 50 F (35 to 10 C). Elevations have been between sea level and 4,000 feet (1,200 m). I did not use trekking poles and pack weights were between 10 and 20 pounds (4.5 to 9 kg).

Trails have been mostly forest and meadow, and ďnon-technicalĒ i.e., not rocky, especially steep or badly eroded. I still havenít encountered rain, although I twice missed it by a just few hours! Oh well. I also cycled with it several more times.

Packing & Gear Retrieval

Didnít stray much from how I packed during the Field Report, although I finally used the little elastic tool straps to attach a tripod. They held but the tripod moved a lot while I walked and could use a stout, non-stretchy anchor. At least I didnít rip the elastic bands off, so no complaints about their strength. Finding I like to load it from the top and then often retrieve gear using the front panel zipper. The clever design is helpful and I just need to remember to use the compression straps that help prevent the zipper from opening on its own.

Cycling duty.

On the Go

I canít fault how the Z 35 carried. Itís comfortable regardless of how empty or full it might be. In cooler weather when Iím wearing more layers, the back ventilation is as welcome as when itís hot, because my back stays drier and warmer. Load control is the best of many positive features; this suspension just works. It helps that the pack fits correctly. For this test segment I only carried water bottles (as big as 1 liter), not a reservoir. While they retrieve easily from the side pockets itís not easy to slide them back in while wearing the pack due to the snug elastic pockets. Bottles donít fall out either, so thereís also a benefit to the design.

Had opportunities to carry use the pack after dark, when the bright fabric was really welcome for retrieving gear. I can attest changing black lenses on a black camera is not easy in a black pack, so the Gregoryís bright yellow fabric is welcome. Have also had other hikers tell me how far away they can spot the pack on a wooded trail, which is exactly what I want during fall hunting season!


The Z 35 is still in very good condition and Iíve finally managed to get it dirty and sweat-stained, in spots. ďA dirty pack is a happy pack.Ē Buckles and zippers all work as new, stitching is holding and the straps are fine. I donít see any fabric snags or tears, including the elastic sections. I haven't dropped it down any mountains (something that has happened to me more than once) but I didn't baby it either, like I must with very thin-fabric packs I've used.


As a large day pack the Z 35 is versatile and engineered to handle large and hefty loads that a simple rucksack won't. Echoing what I've already written, it has been comfortable throughout this test, regardless of the load, the trail or the weather. Weight doesn't "disappear" but it's kept tolerable when a lesser pack would conspire with the load to cripple me. And with a light enough load I can actually forget it's there, basically the highest compliment I can pay to a backpack.

Recommendations for Improvement

Nothing to add beyond my Field Report, where I noted Iíd like a solid anchor for strapping heavy gear to the outside. This is mostly to support uses not related to my typical day hikes, but in addition to lashing a tripod I can also envision a wintertime benefit for strapping on my snowshoes. I might tackle that challenge this coming winter.

Future Use

Iíll happily keep using the Z 35. Its capacity, comfort and stability make it a great day pack when I have large loads and it serves well for non-trail uses, too.


My sincere thanks to Gregory Mountain Products and for the chance to test the Z 35.

Copyright 2014. All rights reserved.

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