Reviews > Packs > Internal and External Framed Backpacks > Gregory Jade 50 or Z55 Pack 2007 > Test Report by Thomas Vickers

Gregory Mountain Products Z 55 Pack

Initial Report - June 6, 2007
Field Report - August 14, 2007
Long Term Report -October 14, 2007

Tester Background:
I grew up in the piney woods of southeast Texas. Camping was a quick trip into the mosquito-infested woods behind the house. My style has evolved and over the last 4 or 5 years, I have begun to take a lighter weight approach to hiking gear (I still use sleeping bags and tents, just lighter versions). While I have flirted with lightweight hiking, I feel that I am more of a mid-weight hiker now. My philosophy is one of comfort, while carrying the lightest load possible.

Initial Report
June 6, 2007

Initial tester expectations:
I love going to the Gregory Mountain Products website. It is easy to navigate and full of useful pictures and information.  I came away from the site with a few questions, but not because the site was lacking information. The 3D pictures showed me what I think is the Jetstream suspension and from viewing on the site, I am intrigued by it.  I guess in this case, the website had more than enough information, but nothing substitutes for holding new gear in my hands.  I like the feeling that I know what to expect before the Z 55 arrives.

Description from the manufacturer:
With an all-new ventilated Jet Stream™ Suspension, this durable, yet lightweight pack carries like a dream. Thru hikes, lightweight three day weekends, or trips to the crag are just a few places you'll enjoy wearing this fully redesigned classic. Jet Stream™ suspension system-Auto.Fit harness system-Ventilated, moisture wicking harness and waistbelt system-7001 T6 aircraft aluminum hollow stay-Weight reducing molded V-beam framesheet-Top and side access-Expandable front Bucket pocket-Secondary front pocket-Water resistant top pocket and front pocket zippers-Water resistant side access zipper-Dual quick access waistbelt pockets-210D HT double box ripstop nylon-210D HT nylon twill.

Tester's Description:
Fabric:
The Z 55 pack is constructed from 210D HT "Double Box" Ripstop Nylon fabric and 210D HT Nylon Twill fabric.  I am not really sure which is which, but from inspecting the pack I think the yellow portions of my pack are the "Double Box" Ripstop Nylon and the bottom and parts of the top pocket are made from the Nylon Twill.  The yellow portions are smooth and slick to the touch despite the being able to see the ripstop threads in the fabric.  The Nylon Twill is gray in color and are rougher than the other fabric, but not as rough as other pack fabrics I have encountered.   Overall, the fabrics used on the Z 55 look and feel nice, but they also seem to be fairly light weight.  Many times I have wondered why pack makers don't use lighter, yet durable fabrics on their products, but Gregory Mountain Products seems to have answered my wondering with the Z 55. 

Lid Pocket:
The lid pocket on the Z  55 does not appear to be that large.  The opening on the lid pocket measures 9 in (23 cm) across and 8 in (20 cm) deep. There is only one zipper pull on the lid pocket and the entire lid seems to be removable without much hassle.  There are two plastic sliders which attach in the front of the pack and two plastic snaps that attach to straps on the back of the pack. I had the entire lid removed in less than two minutes and it only took about three minutes to get it back on.  One thing that became apparent as I looked over the Z 55 is that the webbing straps in several locations are very long and the ends are not sewn over.  This means that I can get the straps into and out of the plastic sliders quickly and easily.  I can also cut the straps off to a shorter length without much trouble as well.  I really like the fact that Gregory didn't go to the expense or effort to fold over and sew the ends of the straps.  It means less hassle for me if I want to remove a strap quickly.

Front Bucket Pocket:
Gregory's front bucket pocket is a bit difficult to describe. In essence, it is what I have always referred to as a "shove it" pocket. The difference is that rather than being a flap of fabric held shut by a strap, the Gregory Bucket Pocket is attached to the pack by a stretchy material on the sides and sort of combines a normal 'shove it' pocket and side mesh pockets into one big pocket.

This photo shows the bucket pocket, the gray stretchy material and mesh that attaches the pocket to the pack, and the top of the pocket which contains a strap that allows the bucket pocket to be cinched tight against the pack body. I am interested to see how easy it is to utilize this pocket to carry items that may need to dry out or get put away or accessed in a hurry. 

Secondary Front  Pocket:
On the front of the Bucket Pocket is the secondary front pocket. This is basically a zippered pocket on the front of the bucket pocket which is accessed by an 11 in (28 cm) zipper.  The placement of this pocket really makes me wonder about its functionality. If the pack and bucket pocket are full, how much will fit into the secondary front pocket? Will I even be able to get anything into it?  While this does seem like a nice extra on the Z 55, I am going to pay close attention to how functional it really is.

Suspension:
The Z 55 has several suspension elements that I am interested in. The first is the 7001 T6 hollow aluminum stay. I haven't weight it yet. In fact, I haven't even tried to remove it yet, but from my quick examination of it and its pocket on the inside of the main pack bag, I think I can get it out if needed. The other part of the suspension that intrigues me is the Jet Stream Suspension System.  This is a combination of a "lightweight perforated framesheet combined with  Aerotech mesh backpanel" which is supposed to promote ventilation between the pack and my back.

It took some investigation and putting the pack on a few times to find a way to translate this into normal language. From what I can tell (see photo above) the framesheet is curved and pulls/holds the pack body away from my back. Running between the lumbar and shoulder pads of the Z 55 is a tightly stretched piece of mesh.  This piece of mesh causes the pack body to ride about 1.5 in (4 cm) away from my back rather than right up against it.  Since internal frame packs always lead to a sweaty back, I am really interested to see how well this system works in the field.

Main Pack Bag/Compartment:
An opening at the top, which closes by a drawstring and toggle and from the side by a zipper, accesses this compartment. The side zipper is crescent shaped and about 18 in (46 cm) long and is designed to provide access to the pack while it is loaded.  I also discovered to my delight that there are dual hydration ports located on either side of the top of the main pack compartment. Finally, a simple solution to a simple problem; two holes instead of one.  It probably isn't  a big deal and I have no real personal preference of which side I drink from, but I like having the option of choosing either one on a whim.   Part of the main compartment is an extension collar that can be extended to increase the pack volume  There is also a compression strap that hooks over the top of the main compartment to help cinch the Z 55 Pack down when it is not quite full.

Compression Straps:
The Gregory Z 55 Pack seems to have straps coming out of every spare spot. There are cinch straps, sleeping pad carrying straps, gear lashing straps. No matter how I slice it, I come up with a new strap on the Z 55. One thing that I like about all these straps is that they appear to be functional. I often feel that packs don't have enough cinch straps to help adjust the load, but Z 55 almost goes too far in the other directions.  I also like the fact that despite there are so many straps, Gregory seems to have still gone to great lengths to make sure that weight is minimized.  All the straps that I have found are only 3/4 in (2 cm) wide and the quick release buckles are a new design that seems to maintain functionality while reducing weight.  The straps are also very long and it appears that they are designed to be trimmed by the pack user to a length that pleases the individual pack user.  So, despite the fact that I think Gregory went strap happy with the Z 55, I think all the straps and buckles serve their purpose and are designed to be functional and light weight.

Shoulder Straps/Sternum Strap:
The shoulder straps on the Z 55 are interesting in several ways.  The first is their "S" shape, which causes them to fit rather comfortably across my chest, then they travel back under my armpits.  I don't think I did the description a lot of justice, but the "S" shape is very different from what I am used too. I guess they are a bit more "contoured" or "fitted", which provides for a more comfortable feeling when wearing the pack. I don't feel so constricted with these shoulder straps. The start off over my shoulders, cross my chest, then fade out of my way under my arms. They start out 3.5 in (9 cm) wide at the top of the shoulder strap and narrow to 1.5 in (4 cm) at the bottom of the strap.  The padding isn't that thick, but I think the idea here is too reduce weight (less padding) by making a shoulder strap that fits the body better.  The shoulder straps are easily adjusted at the bottom where they attach to webbing which then attaches to the side of the pack.  My only issue with them is that while all the other straps on the Z 55 seem overly long, the load lifter straps at the top of the shoulder pads are short. It takes quite a bit of grabbing in order to get a grip on them. A little more load lifter strap length and adjusting the top of the shoulder straps would be extremely easy with the Z 55 on my back.

The last part of the shoulder straps that I want to talk about is the sternum strap.   It uses a strange design which attaches both sides of the sternum strap to a round, stiff piece of cord on each shoulder strap. The sternum strap can be adjusted to any location along the shoulder straps by sliding it along this "cord". 

Waist belt:
I am just going to jump out here and say that the waist belt blows me away. It is another great example of "less is more" that seems to be the theme on the Z 55.   The padding isn't that thick, but the tapered shape of the belt is very comfortable around my waist.  The inside of the waist belt has a kind of "waffle" pattern in the foam.  This is probably part of the moisture wicking system that the hang tag described and it is soft and comfortable.  Next on my list are the two mesh pockets, one on each side of the waist belt. The pockets (zipper close) measure about 6 in (15 cm) long, 3.5 in (9 cm) high and 2 in (5 cm) deep. They won't hold much, but hopefully they will be handy and easy to access while moving on the trail. Just the perfect spot for my knife and lip balm.  Last, but not least is the cinch system on the waist buckle.   The adjustable webbing strap is 1.5 in (4 cm) wide and there is a quick release buckle to close the waist belt and a special slider at the other end of the webbing that allows me to tug one direction on the webbing and the waist belt cinches down tightly. No need to bend over, dance a jig on one leg, and have a friend push on the pack just to get the waist belt tight.  If nothing else comes of this test, the whole waist belt, cinch, pocket, wicking system has me impressed, and that is all before I have even put a real load on the Z 55.

Impressions:
The Gregory Mountain Products Z 55 Pack is a great attempt at making a full featured pack that doesn't break my back.  At every turn I have found features that I like, but rather than having the entire kitchen sink thrown in without worrying about weight, Gregory seems to have thought out the Z 55 and made functionality and light weight work together.  I am really hoping that the idea behind the Z 55 translates into an enjoyable field experience with this pack.

Test Strategy:
Here are some questions that I plan on using as a guide for my testing of the Gregory Mountain Products Z 55 Pack

Fit:
1. What is the auto-fit harness system? How does it work?

2. Is the autofit harness system easy to use? Does it work properly?

3. How well does the Z 55 fit with a small load in it? Does it compress to a manageable size? 

4. How wide are the chest straps?

5. How thick is the waistbelt?  

6. Is there a sternum strap on this pack? 

Use:
1. How easy is it to pack the Z 55? 

2. Can I use stuff sacks or will too many “lumps form” and make the Z 55 uncomfortable? 

3. How well does it load without stuff sacks? I prefer the “Stuff it all in” method which doesn't use any stuff sacks. 

4. How well does the Jet Stream Suspension work/feel under heavy loads  (25-30 lbs/11-14 kg)? 

5. How well does the Ventilated, moisture wicking harness and waistbelt system work? It is HOT in Texas and probably New Mexico during the summer.  

6. How does this pack feel and respond while loaded? Does it feel “heavy” or is it comfortable to wear? 

7. How easy is it to get this pack on and off while loaded?  

8. How much can the top pocket hold? Is it large enough to be useful? Or is it too small? 

9. How much can the expandable bucket pocket hold? How well can I access it while the pack is loaded? 

10. How easily accessed are the hipbelt pockets while the pack is being worn? How large are they? How useful are they? 

11. What exactly is the secondary front pocket and where is it on the pack? 

12. Can the aluminum stay be removed? 

Durability:
1. How well do the zippers work? Are they really water resistant or do they leak?

2. How durable is the 210D HT ”double box” ripstop nylon and 210D HT nylon twill? 

3. Will the pack material abrade from normal use? Will it hold up for the entire test period? 

4. How well do the buckles and sliders on this pack work? Will they crack or break after prolonged use? How easy is it to work the buckles with gloves on?

Final thoughts:
I can't wait to take this pack out.  It has felt so good in my initial inspections and fittings and I hope that I still feel that way after I have many trail miles under my belt.  I have not put a real load in the Z 55 yet, but just wearing it around the house to get a feel for it has really impressed me. If I had to describe the Z 55 in one phrase right now, it would be something simple; "More is less."   I had fully expected this to be a retread of the original Gregory Z pack, but I think that Gregory Mountain Products has gone a step further and created a new and exciting descendant of the Z pack in the Z 55.

Field Report
August 14, 2007

Test locations:
Sam Houston National Forest

Test conditions:
Hot, dry, and humid.
Day time temperatures from 70 F to 95 F (21 C to 35 C)
Forested trails with little or no elevation change

Trip 1:
Three days
32 miles (52 km)
Pack weight - 23 lbs (10 kg)

Trip 2:
Two days
12  miles (19 km)
Pack weight - 18 lbs (8 kg)


Getting packed:
The first thing I do with a pack is sit down and try and figure out where everything goes.   The night before my first trip I did just this with the Z 55. I put my rain gear and toiletries in the top pocket, my towel in the front pocket, tent poles in the bucket pocket, and then I loaded the main compartment. My sleeping bag went in first, tent next, cooking system, water filter, food, and then water.  My Z Rest sleeping pad was then slipped through the webbing straps at the bottom of the pack and I was nearly done.   I put my GPS in one belt pocket and my digital camera in the other.  I figured I was pretty much all packed, but there was still plenty of room in the Z 55.  This first load out was my heaviest of this portion of the test and the pack topped the scales at 23 lbs (10 kg). 

On the trail and off the trail, the Z 55 was extremely easy for me to pack, unpack, and repack.  My only issue was with the drawstring that controls the top of the main pack compartment. I don't think that I was ever able to get it cinched shut tightly enough to really please me.  I am going to play with this more in the next phase of the test, but right now it is pretty much the only complaint that I have.

Hitting the trail:
Summer is HOT here in Texas. I don' think there is any way to wear any pack and not become drenched with sweat.  Even wearing the Z 55 and its fancy suspension was no relief from the heat.  I will say that the "Jet Stream Suspension" makes the Z 55 much cooler than any other internal frame pack that I have ever worn, but I still had a sweaty back. I think the best way to describe the "Jet Stream Suspension" as far as being on the trail is that it does allow a lot more air to flow between my back and pack.  This does not get rid of the sweat, but it does keep my back much cooler than I would have expected.  I have to really give Gregory some high marks on this part of the Z 55.

I also like the fact that I don't bump my head or arms on the Z 55. It has a nice low and narrow profile when being worn. No matter how I moved, twisted, or turned, I was happy with my mobility and flexibility while wearing this pack.  I really enjoyed the fact that the Z 55 has integral bottom straps that can carry my sleeping pad.  I spent a lot of time ducking under branches and fallen trees along the Lone Star Trail and it was nice to be able to do this without snagging my sleeping pad. It was nice to be able to wear a pack that has such a great profile and doesn't interfere with my mobility, especially in the piney woods here in Texas.

Comfort:
The Z 55 was extremely comfortable despite the heat here in Texas.  It fit snuggly against my body and even when I jogged for short stretches, it stayed put. There was not any wobbling or slipping no matter how I moved in the Z 55.  It was actually a joy to be able to move a fast as I needed to without stopping to adjust my pack.  Best of all, even after moving fast or after climbing out of a creek bed, I didn't have to readjust the Z 55. Once I got it on my back and adjusted properly, it stayed put.   This was a feature that I really enjoyed. 

Other comments:
There really isn't anything that I don't like about this pack.  The hip belt pouches are just the right size for my camera and GPS and they are both easy to get to when I am wearing the pack.  There are two hydration ports on the Z 55 and they are both big enough to allow a bite valve through without any problems. The buckles on the webbing straps work well and they have held up to a lot of buckling and unbuckling. I could go on and on, but in my opinion, the Z 55 is the pack that keeps on giving.  It is comfortable to wear, it holds more than enough gear, and it has plenty of extras. Every now and then I expect to find the proverbial 'kitchen sink' attached to it somewhere. This pack is just well thought out, well built, and well executed. 

I am looking forward to putting even more miles on this pack with a little heavier load as the temperatures cool off here in Texas.  It is a real pleasure to wear and I am hoping that loads above 25 lbs (11 kg) will not curb my enthusiasm for the Z 55.

Long Term Report
October 14, 2007

Test locations:
Sam Houston National Forest
Other areas in Southeast Texas

Test conditions:
Hot, dry, and humid.
Day time temperatures from 80 F to 95 F (21 C to 35 C)
Forested trails with little or no elevation change
Bushwhacking

Trip 1:
Two  days
17 miles (27 km)
Pack weight - 22 lbs (10 kg)

Trip 2:
Three days
20  miles (32 km)
Pack weight - 19 lbs (8.6 kg)

Summer in Texas:
Summertime in Texas is not the time to be doing much backpacking. This also means that it is the perfect time to see if a pack is going to make me miserable on the trail without me having to get too far from home.  I have put the Z 55 through its paces this summer and it has held up to the worst that the summer heat had to offer. 

I am glad to report that the Z 55 was comfortable and fun to wear, even in the summer heat.  I feel that it really was cooler to wear than most internal frame packs I have used, but this doesn't mean that it was like walking around in the air conditioning. I got hot, I sweated, and I cursed myself for wearing pack in the heat, but I do know that the suspension and other features of the Z 55 made it more bearable than it would have normally been. 

Below is my standard base loadout for all of my trips this summer. I often carried more water, more food, and more luxury items (books, mp3 player, etc ) than are shown, but these items were ones that were always in the pack.

Basic summer loadout for the Z 55 Pack:

	Top Pocket: First aid bag Personal grooming bag Camera Tripod Fuel Bottle Water Filter	weight: 2 lb 1.35 oz (945 g)
	Secondary front pocket: Rain pants Rain jacket Pack towel	weight: 1 lb 5.60 oz (612 g)
	Bellows pocket: Tent poles	weight: 15.95 oz (453 g)
	Main compartment: Tent Food Sack Pillow Cook set Sleeping bag Hydration system	Total weight: 11 lb 13.30 oz (5.37 kg)

Questions answered:
Fit:
1. What is the auto-fit harness system? How does it work?
I really wish I could explain this more. I could not really tell any difference between the auto-fit harness system and the suspension on any other pack that I have used. It seems to work the way it should. I put the pack on, then adjust one or two straps till the load rides just the way I want it to.

2. Is the autofit harness system easy to use? Does it work properly?
It seems to work properly and I don't recall having to be a contortionist to reach the adjustment straps while wearing the pack.  I also know that once I adjusted the load to my back, it stayed put and fit really well no matter how fast I was moving.

3. How well does the Z 55 fit with a small load in it? Does it compress to a manageable size? 
The Z 55 works pretty well with a small load. I hate to say this, but it was almost too big for the size of my summer gear. It spent a lot of time cinched down to what is probably its smallest dimensions during my trips.  The best news is that the Z 55 wasn't a huge bellowing bag of air. I was able to cinche it down to a controllable size without any difficulty.  I would liked to have been able to really cinch it down smaller, but that isn't a deal breaker for me, just another thing to add to the wish list.

4. How wide are the chest straps?
The chest straps are 2.5 in (6 cm) wide at their widest point and much better padded than I expected.

5. How thick is the waistbelt?
The waistbelt is 5.5 in (14 cm) wide and I can't accurately measure the thickness. It is thinner than what I consider a normal pack waistbelt, but considerably better padded than most ultralight packs I have seen.   

6. Is there a sternum strap on this pack? 
Yes there is a sternum strap and it was easy to use (it moved via a slide mechanism) and it snapped open and closed very easily.

Use:
1. How easy is it to pack the Z 55?
Packing was never an issue. The top of the main pack body opens more than wide enough for me to stuff anything I want into it. Taking stuff out was just as easy. My only complaint was that I never seemed able to get the cinch cord at the top of the main pack compartment to close tightly enough to please me.  

2. Can I use stuff sacks or will too many “lumps form” and make the Z 55 uncomfortable? 
I tend not to use stuff sacks because they add weight and make lumps in my pack. Due to the low weight of my summer gear, I carried a lot of it in stuff sacks just because I could. Despite being lumpy, the stuff sacks did not press against me or cause any discomfort.  The front of the Z 55 is padded pretty well and I never had any issues with hot spots or pokes from something in the pack. 

3. How well does it load without stuff sacks? I prefer the “stuff it all in” method which doesn't use any stuff sacks.
The good thing about filling this pack up without using stuff sacks it that I can cinch the load down if it gets too big or tries to expand on me. Even when unstuffed, my summer load never made the Z 55 bulge or unbalanced.  The cinch straps work great and helped me manage the size of the pack pretty well.  

4. How well does the Jet Stream Suspension work/feel under heavy loads  (25-30 lbs/11-14 kg)? 
I never really pushed the suspension past about 25 pounds (11 kg) during the summer months. I will say that even that that weight this pack was a pleasure to wear. It hugged my back and did not bounce even when I was pretty much running down rough trails.  I have to say that the Jet Stream Suspension works pretty darned well.

5. How well does the Ventilated, moisture wicking harness and waistbelt system work? It is HOT in Texas and New Mexico during the summer.
It gets REALLY hot here in Texas and I know that I am going to sweat a huge amount while wearing any pack. I did not think that the Z 55 was any hotter than other packs I have worn and I also feel that is was cooler and better ventilated than I expected.  It didn't perform any magic acts as far as heat and sweaty backs were concerned, but I do think that the harness and waist belt dried out quickly after I took the pack off.   

6. How does this pack feel and respond while loaded? Does it feel “heavy” or is it comfortable to wear? 
It never felt heavy. It was always a pleasure to wear this pack. That says a lot here in Texas, especially with the heat and humidity.  Even when I was moving quickly or scrambling out of creek beds, the Z 55 was always extremely comfortable.

7. How easy is it to get this pack on and off while loaded?  
I have to say that the Z 55 is pretty  normal for a pack as far as getting it on and off is concerned.  The one thing I did like was the fact that the size of the pack tended to make it easier to handle while I was swinging it on or off of my back. It was compact enough that it didn't try to swing out of control and this made it fairly easy to handle while putting it on or while taking it off.

8. How much can the top pocket hold? Is it large enough to be useful? Or is it too small? 
I got far more in the top pocket than I expected. It was a nice place to store items (See picture above) that I wanted to access without tearing into the main pack compartment.   This normally included my First aid bag, personal grooming kit, camera tripod, fuel bottle, and water filter.

9. How much can the expandable bucket pocket hold? How well can I access it while the pack is loaded?
The expandable  bucket pocket can probably hold more than I tried to put in it. Normally I just stuck my tend poles into this part of the pack.  I would still rather see a couple of mesh side pockets and a standard "shove it" flap on the back of the pack. The idea of combining the two makes it a rather interesting job to put items in or take items out of this area when the pack is loaded. 

10. How easily accessed are the hipbelt pockets while the pack is being worn? How large are they? How useful are they? 
I really like the hipbelt pockets. I had not problem getting into them while I had the pack on and they are just the right size to be useful. They were not too small which means nothing fits nor were they too large which would have led to me over packing. On most trips they held my camera and GPS and made them easily accessible when I wanted them.

11. What exactly is the secondary front pocket and where is it on the pack?
This was the most interesting pocket because my initial reaction was "I will just be able to force my stove's windscreen in there."  I was pleasantly surprised when I was able to get the windscreen, pack towel, rain jacket and rain pants into this pocket. It is located on the back of the pack and comprises the rear portion of the expandable bucket pocket.

12. Can the aluminum stay be removed? 
Probably. The stay has a flap over it that closes via hook and loop fasteners.  I attempted to remove the stay a couple of times and it came a little ways out, but was too slippery for me to completely remove it by hand. I didn't want to get the pliers out or mess things up before the test was over, so I left it as a probably, with enough time and effort.

Durability:
1. How well do the zippers work? Are they really water resistant or do they leak?
All the zippers on the Z 55 work really smoothly. I didn't test it in any really rainy weather, but I know that no sweat got in! The main zippers that I used regularly were on the hip belts and they worked just find despite a lot of heavy use. 

2. How durable is the 210D HT ”double box” ripstop nylon and 210D HT nylon twill? 
I have to say that is is pretty darn durable considering the piney woods puts out a lot of sticker bushes and snags during the summer.  I would have predicted that I would have at least one serious scuff/snag at this point, but the Z 55 shrugged the brambles and branches off pretty well. 

3. Will the pack material abrade from normal use? Will it hold up for the entire test period? 
I have seen no abrasions from anything I have done with this pack and that includes rubbing against some serious trees when working over or under blow downs on the trail.

4. How well do the buckles and sliders on this pack work? Will they crack or break after prolonged use? How easy is it to work the buckles with gloves on?
I never had to work with gloves on, so I can't comment on this. I will say that the buckles and sliders are smaller than I expected, but they have been durable. Even the summer sun here in Texas has not made them brittle in any way.  They have all held up very well during this test.

Final thoughts:
I really enjoyed testing this pack. It was almost too big for my summer gear, but I don't think that I would have enjoyed another pack as much in the heat.  The suspension of the Z 55 made it a pleasure to carry and kept my back a great deal cooler than with a regular internal frame pack. This doesn't mean that I didn't sweat in this pack, but it does mean that it could have been a lot worse.

I also enjoyed the fit and comfort of the Z 55. It was so easy to compact down and take off down the trail. No matter how fast I moved or how rugged the terrain was, this pack rode comfortable on my back without any  movement. I strapped it down where I wanted it and it stayed there. 

Most of all I feel that Gregory Mountain Products has taken great care to craft a light weight pack that is full of features. Rather than cut corners and take the bells and whistles off to save weight, the Z 55 is a full featured pack that also manages to keep the weight down.  I consider it a great compromise between features and weight without any sacrifices on either side of the equation. 

Reviews > Packs > Internal and External Framed Backpacks > Gregory Jade 50 or Z55 Pack 2007 > Test Report by Thomas Vickers