Gregory Z40


medium large
Weight 3 lb 4 oz / 1.50 kg 3 lb 7 oz / 1.55 kg
Capacity 2441 cu in / 40 L 2563 cu in / 42 L
Torso length 18 in - <20 in 20 in - 22 in



I love this pack! I was looking for a pack that could…

Rating: rated 5 of 5 stars
Price Paid: $120

I love this pack! I was looking for a pack that could get small enough for a day pack but also get big enough to hold my gear for an overnighter. It did the job. The crossflow system provides excellent air flow to avoid the sweaty back.  

Without a rainfly it did well in wet conditions but not in a downpour. That's why I'm glad they added the rainfly. I also like how they added the sleeping back compartment in the bottom.

Overall this is an amazing pack!


It's not the lightest pack of this size, but it is…

Rating: rated 4 of 5 stars
Source: bought it new
Price Paid: $140


It's not the lightest pack of this size, but it is very comfortable so far, and seems very durable.


  • Very comfortable
  • Packs down nice when empty
  • Very durable
  • Includes rain cover
  • Breathable back
  • Reasonable weight


  • Tiny waistbelt pockets
  • very small "sleeping bag compartment"

I like this pack. I do a lot of hiking where there isn't always a trail, and this pack hugs my body very well while still providing air flow to most of my back. It's a very stream-lined, snug fitting design. Almost too small for a multiday pack (unless your a minimalist), and a little excessive for a day pack (unless you're very comfort driven).

I CAN fit all of my long distance hiking gear in it, but the Z45 or Z50 would probably be a little more ideal for carrying larger amounts of food, water or clothes. Again, if you're a minimalist or have the most compact gear you can get, this should be fine. My bag weighs 21 lbs. with everything in it, and it is very comfortable.

Now for the design of the bag. It has access points to the main compartment from the top, bottom, and the front, leaving plenty of options for you to get at all of your gear very easily. A folding top flap with two pockets in it. The top pocket is much larger than the bottom (on the under-side of the flap, almost a secret pocket).

The inside of the bag has a flap and a zipper for an optional separate sleeping bag compartment (barely fits a pair of sandals, a sleeping bag will not fit), a water bladder sleeve that goes all the way to the bottom of the pack, and two ports for the hose, one on the outside of each shoulder strap.

There are two outside mesh pockets, one on each side of the pack, and two mesh pockets on the waist belt. Unfortunately the belt pockets are the only part of this bag that I consider somewhat of a waste, due to their almost useless size. I don't know if my headlamp even fits in them.


Most comfortable pack I have owned. Great padding…

Rating: rated 5 of 5 stars
Source: bought it new
Price Paid: $169


Most comfortable pack I have owned. Great padding without being to cumbersome. Great from travel, day and multi-day hikes.


  • Gread padding in waist and shoulders
  • Instant access to entire inside at once


  • A bit on the heavy side
  • Top flap not removable

I have had this bag for the last three months, including a cross-country road trip, with lots of day hikes. This bag has been with me to the bottom of the Grand Canyon and back on a three-day trip.  Most recently I just spent the last month traveling around Turkey with this bag. It was small enough to fit under my seat during bus trips within the country, but big enough to hold everything i needed for a 3 day hike. Also worked well for day hikes using the compression straps on either sides. This bag is also small enough to fit in the over head compartments of airplanes so could be used as carry-on luggage.

Access to the main compartment was easy with the main zipper, which avoids the problem that most "tunnel" style backpacks have. Which is that you have to take every thing out to access things buried at the bottom great for trips where you sleep in different place every night. Extremely comfortable even when overloaded. Spent the last day overloaded walking around Istanbul with about 20kgs worth of gear and barely noticed.  Extremely comfortable Im 6 ft 200 lbs and the large size fit me like a glove.  an added bonus is the integrated rain cover pocket with rain cover.

I'm pretty hard on my gear and the pack seems to be holding its own. A few nicks and scrapes here and there but the construction seems to be solid.