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Reviews > Packs > Internal and External Framed Backpacks > Black Diamond Astral Backpack > Test Report by Gail Staisil

Black Diamond
Astral 40 Backpack
Test Series by: Gail Staisil, Marquette, Michigan

Page Contents:

Initial Report:author
March 30, 2012

Tester Information

Name: Gail Staisil
Age: 59
Gender: Female
Height: 5' 9" (1.75 m)
Weight: 152 lb (69 kg)
Location: Marquette, Michigan USA
Email: woodswoman 2001 AT yahoo DOT com

For the last 20 years, backpacking has become a passion. I am a four-season backpacker and an off-trail navigator. Although I do take yearly trips to the American West or Southwest, the majority of my trips are in Michigan and Canada. My pack weight varies considerably but my base weight is below 18 lb (8 kg). I am primarily a tarp camper who averages more than 50 nights a year backpacking in a huge variety of weather conditions including relentless rain, wet snow and sub-zero temps.

Product Information

Black Diamond, Ltd.
Model Astral 40
Daiquiri (Also available in Merlot)
Medium (40 L/2,440 cu in)
Manufacturer  Weight
2 lb 8 oz (1.13 kg)
Tested Weight  2 lb 12 oz (1.25 kg)
Model Year 2012
MSRP $159.95 US

Initial Impressions and Product Description 

Black Diamond Astral 40 Backpack
The Black Diamond Astral 40 Backpack arrived in great condition in the color of Daiquiri and the size of medium as requested. The pack was neatly compressed and it looked really quite small upon first glance. I quickly undid the straps and was happy how much the pack appeared to grow. Even though I try to carry a minimalistic amount of gear I do carry everything that I need for any trip (I do not ever have anyone else carry any of my gear although I have been known to carry some of other people's gear if they are newbies or have limitations). That said a 40 liter (2,440 cu in) pack will likely fill a niche for shorter trips. The suggested load level is between 25 to 35 lb (11.34 to 15.88 kg).

The pack had a multi-page and multi-language hangtag denoting features of all the packs in the manufacturer's Enduro Series. The Astral 40 is the smallest pack in that series of technical packs. The Astral 40 is a women's-specific pack and is available in two sizes, small and medium. The size medium is suitable for those with a torso length of 17.5 to 20.5 in (44.45 to 52 cm). My torso length is 19 inches (48.26 cm) and it fits very well. Women's-specific features include shoulder straps and a hipbelt which is designed for a women's body. The pack weighed about 4 oz (113 g) more than noted on both the website and the hangtag. As a side note, this pack is also available in a men's version.

After filling the pack with some equipment I tried it out quickly. It seems to fit well with easy adjustments to the harness and waist belt and I can hardly wait to get out for an overnight with it.

Design and Technical Features
The exterior of the pack features several fabrics (Daiquiri and Gray colors) most of which appear to be some sort of embossed nylon with some cool graphics. There are also stretch-fabric pockets. I did not find any information on the fabrics on the website or on the hangtags.

The front of the pack features a somewhat roomy stretch pocket in the center of the pack. This open-top pocket with partially open sides features a compression strap on each side to adjust the load in the pocket. Paired with a lower set of compression straps they could also be used to compress the pack or secure items attached to the outside of the pack.

The front of the pack also has trekking pole or ice axe loops with shock-corded handle straps.

The load capacity of the pack can be adjusted by the use of a roll-top feature. I like the fact that the roll top features a buckle closure rather than a drawstring like many packs. The front side of the top opening is reinforced with a stiff but flexible band so that the top of the pack can be rolled neatly.

reACTIV Suspension

The Astral 40 Pack features reACTIV suspension. According to the manufacturer "reACTIV suspension lets you move naturally and comfortably with your backpack instead of despite it". The design is patent pending and reportedly allows the hipbelt and shoulder straps to move "in concert" with a person. There are three parts to the reACTIV suspension. They include the reACTIV Hipbelt, SwingArm Shoulder Straps and the V-Lite Frame.

The gender-specific reACTIV Hipbelt is floating or has a strip of webbing that moves freely through the bottom of the back panel to move with my body. Either end of the webbing has a slider to tighten or loosen if desired. The contoured hipbelt also features two zipper
Roll-top feature of main compartmented pockets. Although small in size they could each easily accommodate an energy bar, sunscreen and lip balm, etc. The hipbelt has a two-way webbing closure with a small buckle.

The SwingArm Shoulder Straps are also floating and gender-specific. They connect at the bottom of the pack with cable and housing for reportedly smooth and low-friction movement. The cable and housing is fabric covered but I can feel it through the material. The shoulder straps have load lifters at the top of the straps. The chest strap can also be adjusted by sliding it up and down on its fabric-covered cording. The chest strap is adjustable and the buckle doubles as a whistle.

The V-Lite Frame is made out of 4 mm (0.16 in) 6061 aluminum. The frame can be accessed and removed from a pocket in the interior of the pack.

More Features
Back showing OpenAir Backpanel
The front of the pack also features a removable zippered-top pocket. This neatly fits over the roll top main compartment. The pocket has a clip inside of it for attaching an item such as car keys or other security item.

The OpenAir Backpanel is covered with a stretchable m
esh fabric. I can feel the cushion and see the design of the molded foam through the mesh. The lower part of the backpanel is covered with stretch fabric but it is not mesh. Above the backpanel is a fabric haul loop.Side stretch pocket and compression straps

The inside of the main pack compartment has an access pocket to th
e frame sheet. Near the top of that pocket is a hook-and-loop tab to hold a hydration bladder.

A simple but wide elasticized loop would theoretically hold the middle of a hydration bag to keep it in place. Corresponding features such as a tube port and stretch loops on the harness add in setting up a hydration unit. This type of set-up is different from many in that there is not a separate sleeve for the hydration bag.

The lower sides of the pack feature stretch pockets. These pockets aren't especially tall but the bottom half of my 1 L (1.06 qt) hydration bags fit in the pocket
s. The bags can be further secured by the use of the compression straps. Of course the pockets could instead be used for other items that need to be tucked away.


The Astral 40 Backpack is a full-featured pack at the lighter end of the scale. Although it weighs more than many minimalistic packs it offers more comfort features than some. Part of the pack weight could be reduced by removing the top pocket. I am looking forward to using it on many short adventures of one to three nights.

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Field Report
June 3, 2012

USA Locations and Conditions

During the field test period I have used the Black Diamond Astral 40 Backpack during three different backpacking trips for a total of seven days in the field. Location of the backcountry trips were in Michigan and ranged from hilly deciduous forest to open non-deciduous communities. Elevation ranged from 600 ft (183 m) to almost 2000 ft (610 m).

April Backpacking Trip

Location: Hiawatha National Forest, Upper Peninsula of Michigan
Type of Trip: Trail 
Distance: 15.5 mi (25 km)
Length of Trip: 2 days/1 night
Pack Weight: 20 lb (9 kg) without water 
Sky and Air Conditions: Cloudy and very windy
Precipitation: None
Temperature Range: 28 F (-2 C) to 44 F (7 C)

Pictured Rocks National Lakeshore
Late April Backpacking Trip

Location: Pictured Rocks National Lakeshore, Upper Peninsula of Michigan
Type of Trip: Trail
Distance: 11 mi (17.7 km)
Length of Trip: 2 days/1 night
Pack Weight: 20 lb (9 kg) without water
Sky and Air Conditions: Mostly sunny and windy 
Precipitation: None
Temperature Range:19 F (-7 C) to 49 F (9 C)

Late May Backpacking Trip

Location: Pictured Rocks National Lakeshore, Upper Peninsula of Michigan
Type of Trip: Trail 
Distance: 31.2 mi (50 km)
Length of Trip: 3 days/2 nights
Pack Weight: 22 lb (10 kg) without water
Sky and Air Conditions: Sunny, windy and cloudy
Precipitation: 0.27 in (0.69 cm) rain
Temperature Range: 42 F to 78 F (6 C to 18 C)

Performance in the Field
Wearing the Astral 40 on a three-day backpacking trip
I first carried the Black Diamond Astral 40 Backpack during an overnighter. The first day I hiked nearly 10.5 mi (17 km) and I was thrilled that I didn't have to make many adjustments nor did I have any sore spots. On the second day of that  trip I noticed that the pack was just as comfortable as the first day. During my second trip I loaded my equipment much in the same way with equal results. My pack weight for the first two trips was identical at around 20 lb (9 kg) plus 4 lb (1.8 kg) of water at the start.

My third trip was a bit longer (3 days) so my pack weight increased by another 2 lb (0.9 kg). This was due to more food and a different tarptent that weighed an additional 8 oz (227 g). Again the pack was quite comfortable during over 31 miles (50 kilometers) of backpacking.

Packing the Astral 40

Since I normally use a hood-less minimalistic backpack, I had to re-adjust where I loaded each item. In the top lid, I placed my rain jacket, rain pants, hat, gloves, pack cover and other incidentals. Even though the hood looked small to me it swallowed all of that gear without over stuffing.

I next loaded the bottom of the pack with my down sleeping bag (30 F/.-1 C), sleeping pad and tarptent, first aid and extra warm clothes (down pants, down jacket and synthetic booties). Things that I might have needed quicker were next placed in the pack such as my stove kit, food bag, etc. All of my gear fit easily and the roll top closure with buckle secures it nicely. The large stretch pocket contained my sit pad and maps as well as some smaller items. The side stretch pockets were each loaded with a filled 1 L (1.06 qt) hydration bag and the waistbelt pockets were loaded with sunscreen, lip balm, small trowel, snacks and more.
The Astral 40 showing where I attached a removable pocket
During packing everything was going great until I tried to find a place for my personal locater beacon (PLB). Granted one of the zippered-waistbelt pockets might have held it but I like to have it even more accessible by pulling it out of a simple pocket that I attach to all my backpacks. Not only does the de-tachable pocket open with a hook-and-loop tab but two hook-and-loop tabs also secure the pocket to a shoulder strap.

Most backpacks that I have used have load lifters on the shoulder straps that continue down the length of each strap to the lower end of the harness. I normally use that extra webbing to attach the pocket so that the pocket doesn't slide downwards. The adjustable webbing (load lifters) ends on the Astral 40 just at the top of the shoulders so placing the removable pocket is abnormally high to use that area of the strap for attachment.

However, I secured the upper set of hook and loop fasteners over and under the loose webbing and the other on the harness itself. Being able to secure the top of the pocket on the webbing itself keeps the pocket from sliding downwards. Although it sits awkwardly on the top of one shoulder, I can still access the PLB which is high priority with me. 

More Thoughts

The reACTIV suspension system has been working amazingly well The SwingArm Shoulder straps move with me and as noted above, I have had no sore spots or pressure points. Some of the time I haven't bothered to use the chest strap as the shoulder harness is comfortable without having to secure the chest strap too. I absolutely love the reverse-pull belt adjustment. I  have never figured out why more manufacturer's don't use this technique. It is so easy to adjust and it normally needs very little further adjustment during many hours of hiking.
The mesh backpanel has been working well so far. Granted my first two trips were on the cold side but the last trip had warm temperatures and my back felt cool enough.
Tester wearing the Astral 40 during an overnighter
The lower side compression straps have worked exceedingly well in holding my water hydration bags in place. I do have to take the pack off to access the water however as I simply find it awkward to un-do the strap, and pull the hydration bag out. I simply can not get it back in! I know that a good amount of people use hydration tubes/with corresponding internal hydration bags for water but there are a lot of us out there that still prefer smaller quart (or liter) water bottles. I would like to see a built-in or a removable water-bottle holder on the waistbelt. I would gladly sacrifice one of the waistbelt pockets for such a feature. As it gets hotter I will likely add a removable one to the front of the backpack.

Even though the expandable outside stretch pocket is handy, I feel like I have less security in the items placed in that pocket. I have noticed that if the smaller items in the pocket are kind of odd shape or slick that they work their way to the open sides. When I have taken the backpack off at breaks or at the end of the day, the items were almost falling out. I have never had issues with such pockets when they were fully seamed at the sides. I will likely use the pocket for large items only in the future.


So far, I have been really surprised at how well the Astral 40 swallows gear. I thought I wouldn't be able to take it out on more than a three-day backpacking trip but I still have some room to likely add another day or two of food in the main part of the pack plus the compression straps could also be used to secure more gear on the outside of the pack. I hope to test that out in the long term period. Despite a few tiny nitpicks, this is one of most comfortable backpacks I have ever worn right from the start.

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Long Term Report:
July 24, 2012

USA Locations and Conditions

During the long term test period I have used the Black Diamond Astral 40 Backpack during an additional four trips in the field for a total of ten days and six nights. Location of the backcountry trips were in Michigan and ranged from hilly deciduous forest to open non-deciduous communities plus cliff trails above lakeshore. Elevation ranged from 600 ft (183 m) to almost 2000 ft (610 m).

June Backpacking Trip
Looking over a cliff at Grand Island
Location: Grand Island National Recreation Area, Lake Superior, Michigan
Type of Trip: Trail/Off-Trail
Distance: 27.8 mi (45 km)
Length of Trip: 3 days/2 night
Pack Weight: 22 lb (10 kg) without water 
Sky and Air Conditions: Sunny, Cloudy, Thunderstorms 
Precipitation: 1.67 in (4.24 cm) of rain
Temperature Range: 44 F (7 C) to 73 F (23 C)

Late June Backpacking Trip

Location: Pictured Rocks National Lakeshore
Type of Trip: Trail
Distance: 10.5 mi (17 km)
Length of Trip: 2 days/1 night
Pack Weight: 19.5 lb (9 kg) without water 
Sky and Air Conditions: Sunny, Cloudy
Precipitation: None
Temperature Range: 63 F (17 C ) to 84 F (29 C)

Late June Backpacking Trip

Location: Hiawatha National Forest, Michigan
Type of Trip: Trail
Distance: 10 mi (16 km)
Length of Trip: 2 days/1 night
Pack Weight: 19 lb (8.6 kg) without water 
Sky and Air Conditions: Sunny
Precipitation: None
Temperature Range: 64 F (18 C) to 78 F (26 C)

Mid-July Backpacking Trip

Location: Grand Island National Recreation Area, Lake Superior, Michigan
Type of Trip: Trail
Distance: 13.8 mi (22 km)
Length of Trip: 3 days/2 nights
Pack Weight: 21 lb (9 kg) without water 
Sky and Air Conditions: Mostly sunny
Precipitation: Trace of rain 0.08 in (0.20 cm)
Temperature Range: 57 F to 75 F (14 C to 75 C)

Performance in the Field
Backpanel very wet after only a couple miles
I have continued to enjoy wearing the Black Diamond Astral 40 Backpack. The highest weight carried on any of my trips was about 24 lbs (11 kg) with water. The pack has been real comfortable at that weight even during long days of hiking.

The weather was a lot hotter in the long term period. During the first trip moderate heat, rain and humidity were part of the experience. The pack was comfortable but I did notice that the backpanel quickly wetted out and didn't dry much during breaks (this was not during the rain which occurred mostly after hiking). On that trip I hiked about 16.5 miles (27 km) on one of the days. The back of my wool shirt was soaked and so was the pack's backpanel. With no airflow, both remained wet.

During the next two trips the temperatures were higher but the humidity was lower (about 50 percent). During the last trip the humidity was higher and temps were moderate. The backpanel still absorbed moisture and always was visibly wet when I took off the pack.

During one of my backpack trips I did some additional mileage using the pack as a daypack. This included about four mi (6.4 km) overall but less than two mi (3.2 km) of bushwhacking. The bushwhacking was on uneven terrain with lots of descents and ascents through thick brush. The lightened pack felt great on my back and moved nicely with me. I had removed the hood of the pack and the shortened pack didn't snag on any brush. I also wore the hoodless backpack during a dayhike of nine miles (15 kilometers).

During my last backpacking trip I decided to leave the hood of the pack at home. I still had plenty of room for all my gear. Although the hood doesn't weigh much (less than 4 oz/113 g), it still saved me from carrying extra weight.
Added a removable water bottle holder to belt
I ended up adding a removable water-bottle holder to the belt on the last three trips. During the first trip of this period I was frustrated as every time I wanted a drink I had to take the pack off. This resulted in me not drinking enough liquid during moderately hot weather. I simply found the side pockets too awkward to stash my water and retrieve it. I could pull my water hydration bag out but can't get it back in. I vowed that I would add the pocket for the remaining trips and it made it much better. The belt was very adaptable to adding such aDay pack version holder and I was still able to easily make waist belt adjustments.

More Thoughts

The pack has continued to be easy to pack and I still am surprised how easily my gear fits in it. I like the trim profile as there are no hidden corners to lose gear in.
I have continued to store my seat pad, maps and other items in the stretch pocket. The reACTIV suspension system has been working amazingly well. 


There are no signs of deterioration to the pack except for some staining that occurred when I put an almost empty hydration bag in one of the side pockets. I must have not put the cap on correctly and some of the liquid (that had a natural grape electrolyte mix in it) leaked out and stained the pocket and side of the pack. Unfortunately I haven't been able to remove the bulk of the discoloration even with soap. I was more worried about the actual residue attracting bears on the following trips, hence the washing. I did hang my pack sans gear and food just in case any odors lingered during the last two trips. There is also some slight catches in the stretch back pocket but no holes.


Overall I have been pleased with the performance of the Astral 40 Backpack. I like its slim profile. Even though the pack appears small it holds all of my gear without an issue. I could easily add more gear to the pack. I wish the backpanel was more breathable during hot weather but worked fine during the cooler months of the early test period. I would prefer a water holder on the front of the belt but that is my style and may not be what others are looking for. I surely will continue to use this pack after the test period as it is simply comfortable!


  • Women's-specific comfort features
  • Removable top pocket
  • Very roomy pack
  • Great suspension


  • Wish there was a bottle holder on belt
  • Backpanel could be more breathable

Tester Remarks 

Thanks to Black Diamond, Ltd. and for this opportunity to test the Astral 40 Backpack. This concludes the test series.

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