Articles (2020)

Overview

Osprey’s Aether 60 has rightfully become a favorite backpack among many lightweight enthusiasts even though there are lighter alternatives. It is a great stepping-stone for backpackers who are transitioning to lighter loads. The Aether 60 makes its mark by providing a feature-rich, durable, 3,700 cubic inch (61 L) pack which weighs 56.6 oz (1.6 kg). The Aether 60 can handle loads approaching 40 pounds (18 kg) although there was some discomfort in the hipbelt with the heavier loads. It can carry skis, snowshoes, snowboards, ice axes, climbing ropes, kitchen sinks, and other necessary backcountry gear (many of these items can be carried simultaneously). The versatility and durability of the Aether 60 is excessive for those whose pursuit is simply lightweight trail hiking.

Specifications

• Backpack Style	Top-loading internal frame backpack.
• Fabric Description	210d double ripstop used in main pack body and pockets. Heavier 420d “chainlink” fabric used on bottom, sides, and center of compression panel.
• Sizes (Size M tested)	Sizes Torso Length (in) Torso Length (cm) M 16-20.5 41-52 L 20-22+ 51-56+
• Volume (Size M tested)	Sizes Volume (ci) Volume (L) M 3,700 59 L 3,900 64
• Weight (Size M tested)	Sizes Backpacking Light Measured oz (g) Manufacturer Specification oz (g) M 56.6 (1,605) 54 (1,531) L Not measured 56 (1,588)
• Volume to Weight Ratio	65 ci/oz size M (based on 3,700 ci and Backpacking Light measured weight of 56.6 oz)
• Load Carrying Capacity	35 lb (15.9 kg) as estimated by Backpacking Light
• Carry Load to Pack Weight Performance Ratio	10 (based on 35 lbs and Backpacking Light measured weight of 56.6 oz)
• MSRP	$199
• Manufacturers Contact Information	Osprey Packs, Inc. (970) 564-5900 http://ospreypacks.com

Features

Ratings follow subtitles on a scale of 1 to 5, with 5 being the best, and are relative to other Backpacking Light tested framed packs.

Frame and Suspension – 4.0

The frame of the Aether 60 combines two composite rods with an exceptional pack compression system to create a rigid frame for loads up to 35 to 40 pounds (16 – 18 kg). The two composite rods run down each side of the back panel, ending where the hipbelt and shoulder harness stabilizers attach to the pack. This design is a lighter weight version of the frame Osprey uses in its larger packs. Tightening the shoulder strap and hipbelt stabilizers flexes the composite rods like a long bow and quite effectively pulls the packbag into the user’s back. The pack hugs the back and has great flexibility while doing an excellent job of transferring weight to the hips.

The suspension consists of a shoulder harness, padded hipbelt, sternum strap (with whistle), and hipbelt and shoulder strap stabilizers. Osprey’s unique Ergopull hipbelt adjustment straps attach to each side of the hipbelt in two locations, one high and one low, and to a single side-release buckle (Photo 2). Tightening the adjustment straps causes the hipbelt to cup, better forming to the shape of one’s hips. Rather than pulling away from a center buckle, the hipbelt adjustment straps are pulled toward the center buckle. Thus, while tightening the adjustment straps, the user is pulling the padded hipbelt and lower portion of the back panel into his or her lumbar instead of away from it. This adjustment is easier to make and more effective at locking the lower portion of the pack to the user’s lower torso. Unfortunately, we found that the padding used in the hipbelt lacks enough suppleness to perfectly shape to the contour of our testers’ hips, tending to be tighter along the lower edge than it was along the upper. We found the poor fitting belt tolerable, but improvements could be made. The shoulder straps, with their dual density foam, are contour cut, and follow body curves well. The point where the shoulder strap stabilizers attach to the shoulder straps can be adjusted. The sternum strap’s vertical adjustment range is long enough to suit all users, both male and female.

Sizing

The Aether 60 is offered in three sizes to fit torsos from 16 to 22+ inches (41 – 56 cm). In addition, the shoulder harness is easily adjustable. The shoulder straps are connected to a short fabric and Velcro covered frame sheet which slides behind the padded mesh back panel and attaches to Velcro on the backside of the back panel. Field adjustment is a simple matter of breaking the Velcro connection and sliding the framesheet up and down. The question must be raised whether this connection will remain firm under a fully loaded pack. After anchoring the hipbelt to the floor and connecting a fish scale to both loose shoulder straps, I was able to pull over 50 pounds (23 kg) on this Velcro attachment without the slightest sign of release. Now consider that the pack will typically be loaded with less than 40 pounds (18 kg) and that most of this weight will be on the hipbelt. Also, the bottoms of the shoulder straps are connected to the lower back panel, so the weight on the Velcro will be that much less. Bottom line: it’s not going to slip.

Usable Features and Ease of Use – 4.5

The Aether 60 is loaded with features to adapt to a variety of outdoor pursuits. Pockets include two mesh water bottle pockets, a larger mesh back pocket, and a top lid pocket. The two mesh water bottle pockets located at the bottom of each side panel are uniquely accessible from both the top and front-facing side. This allows easy access to smaller items and secure storage for larger items. The pockets are large enough for a 1-liter water bottle and both openings are accessible while wearing the pack. The large mesh back pocket is a handy place to store gear and is secured by three of the back compression straps. The top hood pocket is roomy and fits well atop the pack. A keychain clip on the inside prevents those troublesome “where are the keys!” episodes many of us have experienced upon returning to the parking lot, but just prior to finding them buried in the pack. A double slider #5 YKK coil zipper closes this top pocket.

Plenty of essential attachment points are provided for the backcountry skier, snowboarder, snowshoer, and mountaineer. There are two ice axe loops located below the large mesh back pocket. The back compression straps, which are connected with side-release buckles, are ideal for attaching a snowboard or snowshoes. Along each side panel are attachment points for carrying skis. A climbing rope can be secured by the top lid and the upper ski attachment straps located on each side panel. If this is not enough, there are additional attachment points on the hood pocket and removable sleeping pad straps across the bottom that adjust with side release buckles.

The Aether 60 does not have a hydration pocket. There is a space behind the shoulder strap harness, but it was not large enough to comfortably hold a bladder without bulging the back panel out into the user’s back.

Load Volume Flexibility (Compression) – 5.0

Osprey’s unique compression system easily adjusts to varying load volumes. There are four compression straps on the back of the pack. Combined with the compression from the top pocket, these straps quickly reduce the pack to accommodate decreasing volume over an extended trip. For even smaller loads, three of the compression straps can be disconnected via side-release buckles and reconnected at points along the front of the side panels. They act to fold the left side of the pack over the right (like a burrito) creating a volume suited to day-hikes or a summit push.

The Aether 60 has an extension collar and numerous compression straps and accessory attachment points to attach additional gear to the outside to accommodate larger volume loads.

Options

Osprey offers a line of add-on accessories, such as small day packs and crampon pockets, that cleanly attach to their ReCurve and Ethereal suspension packs. On the Aether 60, attachment points for such accessories lie at the sides of the large back mesh pocket and beneath the back compression straps. The accessory packs attach with sliders that button through D-rings on the Aether 60 pack. Those connections combined with the compression straps create a seamless, stable pack set up. We did not field test any accessories; however, we did observe their attachment at a local backcountry store. They add considerable weight (10 to 21 oz, 283 – 595 g) pushing the Aether 60 beyond a lightweight pack, but may provide some utility for those who occasionally need the extra capacity.

Field Performance

Pack Load Carrying – 4.0

The Osprey Aether 60 was tested with loads of varying volumes weighing from 45 to 20 pounds (20 – 9 kg). We found Osprey’s Ethereal two-composite rod suspension system was well suited for maximum loads of 35 – 40 pounds (16 – 18 kg). The frame, combined with the compression system, maintains rigidity up to 40 pounds but the hipbelt becomes less comfortable above 35 pounds. At this weight some reviewers preferred to shift more weight onto their shoulders. For users who find weight on their shoulders uncomfortable 35 pounds is a more accurate maximum comfortable carrying capacity.

The Aether 60’s ability to easily and effectively adjust to smaller volumes allows this pack to carry small, heavy loads with ease. After loading the pack, the compression strap side-release buckles can be reattached to the side panel attachment points. Tightening these effectively contains the load in as small a volume as necessary, close to one’s back, providing a comfortable and stable pack.

Durability – 5.0

Osprey made this pack to handle a considerable amount of abuse from a lightweight enthusiast. The fabrics used are durable and able to handle many encounters with rock and brush. Nothing has been overlooked in this regard as every likely location where durability could be in question is either made with more hardy fabric or reinforced with Hypalon.

Stitching quality is superb, all of the seams are taped, and countless bar tacks hold it all together under the most demanding use. In short, this pack is built to last.

Value – 4.0

The Aether 60 may be a little heavier and pricier than some would prefer, but it is still a reasonable value considering it has features to carry just about anything found in a backcountry store. The weight is directly reflective of its durability, which will appeal to those covering harsh terrain. On the other hand, these features and durability are excessive for trail hikers.

Recommendations for Improvement

Some reviewers found the hipbelt in the Osprey Aether 60 uncomfortable when tightened down for a heavier load. This is the result of the hipbelt not conforming to the hips, particularly along its lower edge. We’d like to see Osprey redesign the hipbelt.

Overview

At 2 pounds 15.2 oz (1,338 g) without options, ULA’s P-2 is one of the lightest, large volume internal frame packs on the market. ULA was able to achieve these weight savings without sacrificing features and comfort. The basic pack has a total of five exterior pockets, an ice axe loop, and other gear attachment options. The P-2 is offered in four sizes (with five sizes for the hipbelt). We also enjoyed ULA’s exceptional customer service and support. Included with the P-2 is a detailed description of the pack’s abilities, how to adjust the various components, and how to install and remove accessories. The information provided goes beyond the market standard, providing even the novice backpacker the tools necessary to achieve pack adjustment nirvana. At 4,900 cubic inches (80 L) for the base pack, many ultralight travelers will find this large volume pack too cavernous for their backpacking pursuits.

Specifications

• Backpack Style	Internal frame, top-loading backpack with roll-top closure standard. A top hood pocket can be purchased as an option.
• Fabric Description	210d, 4.5 oz/yd2 (153 g/m2) Dyneema Gridstop and 1.9 oz/yd2 (64 g/m2) urethane coated ripstop nylon.
• Sizes (Size M tested)	Sizes Torso Length (in) Torso Length (cm) S 15-17 38-43 M 18-20 46-51 L 21-23 53-58 XL 23+ 58+
• Hipbelt sizing (belt size M tested)	Sizes Waist Circumference (in) Waist Circumference (cm) XS 26-29 66-74 S 30-33 76-84 M 34-37 86-94 L 38-41 96-104 XL 42+ 106+
• Volume (Size M tested)	Sizes Volume (ci) Volume (L) S 3,800 62 M 4,900 80 L 4,900 80 XL 5,100 84
• Weight (Size M tested)	Component Backpacking Light Measured oz (g) Manufacturer Specification oz (g) Base pack 47.2 (1,338) 47 (1,332) Pack with all options 56.3 (1,596) 56.1 (1,590) Top Lid 4.2 (119) same Internal Pocket 1.1 (31) same Hydration Sleeve 1.4 (40) same H2O Holsters (each) 0.4 (11) same Hand Loops (each) 0.8 (22) same Embroidered Name Not measured 0.0
• Volume to Weight Ratio	104 ci/oz size M (based on 4,900 ci, size M, and Backpacking Light measured weight of 47.2 oz)
• Load Carrying Capacity	35 – 40 lbs (16 – 18 kg) as claimed by ULA and confirmed by Backpacking Light
• Carry Load to Pack Weight Performance Ratio	12 (based on 35 lbs and Backpacking Light measured weight of 47.2 oz)
• MSRP	Basic pack – $210 Top Lid – $22 Internal Pocket – $5 Hydration Sleeve – $5 H2O Holsters (each) – $2 Hand Loops (each) – $2 Embroidered Name – $10
• Manufacturer’s Contact Information	Ultralight Adventure Equipment (ULA) (435) 753-5191 http://ula-equipment.com

Features

Ratings follow subtitles on a scale of 1 to 5, with 5 being the best, and are relative to other Backpacking Light tested framed packs.

Frame and Suspension – 4.0

ULA designed the P-2 to handle 35 to 40 pound (16 – 18 kg) loads, both in volume and in weight, in relative comfort. We found the internal frame and suspension were well designed to handle this task. The P-2 has a single removable aluminum stay running the full length of the back panel. The stay fits into a long webbing sleeve sewn into a closed cell foam pad. This closed cell foam, combined with a piece of open cell foam, makes up the dual density padding for the P-2’s back panel. The stay itself is fairly easy to remove for reshaping. However, the tight fitting padding is not, which prevents its use as a sitting pad in camp. The back panel is covered with mesh and moves perspiration efficiently, however there are no channels or grooves in the back panel for air circulation.

The P-2 comes loaded with shoulder straps, padded hipbelt, sternum strap, hipbelt stabilizers, and shoulder strap load lifters. The shoulder straps are contour cut and do a reasonable job of following body contours. However, we found the shoulder strap padding too long, extending beyond what is needed to pad the shoulders. The lower webbing ends of the shoulder straps are attached to the bottom of the pack, rather than to the lower sides and are reinforced by a large delta wing. In theory, this attachment should distribute the weight of a fully loaded pack better to the shoulder strap connection. In our testing, it appears the angle used to connect the triangular piece to the bottom of the pack is slightly too steep causing most of the load to fall on the rear of the triangle connection (Photo 2). However, we do not perceive any problems arising from this since the fabric triangle is much larger than necessary and maintains a significant amount of load distribution so it is unlikely a seam failure will occur. We did not experience any problems with this junction during our testing which included carrying weights up to 50 pounds (23 kg).

The hipbelt is adequately padded and removable. It attaches to the pack with Velcro behind the padded back panel. Torso length adjustment is made by moving the hipbelt vertically along its Velcro attachment behind the lower back panel. We found the hipbelt fit was exceptional due to ULA offering five sizes of hipbelts.

Both the hipbelt and shoulder straps have stabilizers that effectively compress the load into the user’s lumbar and transfer weight to the hipbelt, respectively. The point where the shoulder strap’s stabilizers attach to the top of the shoulder straps is adjustable. The shoulder strap stabilizers can also be removed altogether. The hipbelt stabilizers are not removable.

Usable Features and Ease of Use – 4.0

ULA’s P-2 was designed with versatility in mind. A total of five pockets (six including the optional top pocket) provide storage for often needed items. The P-2 has a single large pocket on the back that is large enough to dry a small tent fly. Two side pockets, measuring 9 inches wide by 14 inches high (23 x 39 cm), cover both lower side panels. Each side pocket can hold a 2-liter water bottle, but the bottles are not accessible while wearing the pack. The P-2 has two camera-sized pockets, one on each side of the padded hipbelt where small, trail accessible items can be carried. The P-2 also has two shingled water bladder tube ports that allow water to be carried in a hydration bladder within the pack.

The P-2 comes standard with a roll top closure. A top pocket can be added as an option. The top pocket is not a permanent alteration and can be removed easily without leaving behind a multitude of extraneous webbing straps or buckles. As a bonus, it is designed to attach to the P-2’s removable padded hipbelt to create a small lumbar pack (including the two hipbelt pockets) suitable for day trips from camp (Photo 3). The top pocket is too small to haul enough gear for a serious summit attempt or enough water for desert water runs. Nevertheless, we find the top pocket very handy when base camping and appreciate the lack of excess hardware when it is removed.

An optional bladder pocket can be purchased that attaches to the inside back panel with plastic quick clips. ULA offers water bottle holsters attached to the shoulder straps as another accessible water carrying option.Another mesh zippered pocket can be added to the inside of the pack for smaller items. Like the hydration pocket, this pocket attaches with removable plastic clips.

Two other options are available for the P-2. For those who don’t travel with trekking poles, two hand loops can be seamlessly added to the shoulder straps to provide a location to rest one’s arms. On the occasions we were without trekking poles, we found these additions comfortable, but wouldn’t have missed them either. The final option is to have your name or trail name embroidered on the pack. This option was not selected; however the examples from ULA’s web site are attractive.

A shock cord covers the large back pocket and adds compression and additional storage. Other exterior attachment options include two straps that run across the bottom and lower back of the pack – ideal for stowing a sleeping pad should the 4,900 cubic inch (80 L) pack volume be exceeded. These are attached at their upper ends with side release buckles and include enough webbing to secure fairly large items. The P-2 also includes a single ice axe loop on its right side with a Velcro attachment above that on the back panel to secure the ice axe handle. Other long items can be stashed into the two side panel pockets, with their ends secured under the upper-side panel compression straps. These straps do not have side release buckles for attachment. Instead they adjust with ladder locks which require that longer items be fished through the straps rather than simply buckling them on.

Load Volume Flexibility (Compression) – 3.0

The ULA P-2 has volume adjustability to meet the needs of various outdoor pursuits (Photo 4). For compression, each upper side panel contains a single compression strap which begins at the lower back panel just above the side pocket, runs to the back of the pack, and then back to the upper back panel where it attaches to a ladder lock. From the side, this strap looks like a sideways V. The bottom sleeping pad straps can also be tightened to compress the lower quarter of the pack. The roll top closure is compressed by a single strap that runs from the bottom back of the pack, up the center of the back, and over the top opening. The heavier than average shock cord over the large back pocket can effectively be used as a component of the compression system. Although the pack looks lumpy and poorly contained when compressed for a small volume load, the contents are stable.

When gear volumes begin to exceed the pack’s internal capacity, gear can be attached to the outside via the multitude of attachment options including the large mesh side and back pockets. The large extension collar will easily swallow a volume equivalent to a winter weight sleeping bag. If additional volume is needed, request the $22 top pocket option to add 400 cubic inches (6.6 L). For most lightweight backpackers, these exterior packing opportunities will not be necessary as the P-2 is already a huge volume pack. But then again, the P-2 has the makings of a super expedition load hauler.

Field Performance

Pack Load Carrying – 4.5

We tested the ULA P-2 carrying loads ranging from 50 pounds (23 kg) down to 10 pounds (4.5 kg) to confirm ULA’s suggested load carrying capacity. ULA recommends carrying weights between 35 and 40 pounds (16 – 18 kg) for best performance with the P-2. We found this to be entirely accurate. While the frame handles 40 pounds with ease, the shoulder straps and hipbelt begin to reach their comfort limit at 35 pounds, 40 pounds is tolerable, and comfort significantly drops off above 40 pounds.

We also tested the P-2 carrying smaller volume, heavy loads (i.e. desert water trips). Employing the full array of compression options, the ULA P-2 carries these loads with great stability but it is not pretty due to the lack of a comprehensive compression system.

One attribute of the P-2 is its stiff single aluminum stay with a relatively flexible framesheet. The flexibility allows great range of motion when hiking, while still being vertically supportive enough to effectively transfer the load to the hipbelt.

Durability – 4.0

Dyneema Gridstop, similar to Spectra Gridstop, was used throughout most of the ULA P-2. This 210 denier high tenacity nylon fabric adds a 215 denier Dyneema fiber in a ripstop/grid pattern. Dyneema is a high molecular weight polyethylene fiber that is, pound for pound, ten times stronger than steel and twice as strong as Kevlar, which translates into this fabric’s high tear strength. We find Dyneema Gridstop very well suited to backpacking on trails and even off trail to some extent. Unfortunately, tear strength and abrasion resistance are not the same. The Dyneema Gridstop requires some attentive care if this pack is used for more aggressive climbing or off-trail pursuits where abrasion is a factor.

Value – 4.5

At $210, the ULA P-2 is very price competitive with other large volume, lightweight internal frame packs on the market. Its relatively low weight and high volume result in the P-2 having one of the highest volume to weight ratios (104 ci/oz, higher is better) we’ve seen in an internal frame pack. We feel the ULA P-2 is an excellent value, offering large volume, great fit, and low weight.

Recommendations for Improvement

Overall, the ULA P-2 is an excellent large-volume, lightweight pack. A couple of changes will bring it to perfection. First, the triangular reinforcing piece that connects the lower shoulder strap webbing to the bottom of the pack is at the wrong angle for a fully loaded pack, putting more strain on the backside of this triangle. We suggest adjusting this angle such that load forces are more evenly distributed. The padded end of each shoulder strap is longer than necessary for most users. The lower portion was wide enough to rub the inside of our arms, causing a little annoyance, though not chafing. (This is by no means a reason to avoid buying this pack.) Either increasing the taper or shortening the padding by about 1 inch (2.5 cm) would alleviate the problem and save some weight in the process. Finally, it would be more convenient if ULA would exchange the ladder locks on the upper side panel compression straps with side-release buckles and longer webbing straps. This would allow longer items that extend out of the side pockets, and climbing ropes slung over the top opening, to be attached with greater ease.

Overview

Granite Gear’s Nimbus Ozone (top loading) and Nimbus Latitude (panel loading) are exceptionally comfortable lightweight packs designed for 40-pound (18 kg) loads. Granite Gear uses soft padding in their shoulder straps that conforms well to the shape of shoulders and collarbones and better distributes the weight of a loaded pack. The Tepex composite frame used in the Nimbus series offers greater adjustability than that found in similarly priced and sized packs. Torso length and shoulder width are both adjustable. The packs have some of the best load compression in the industry. One complaint with both the Nimbus Ozone and Nimbus Latitude is that the load compression straps cut across the top of the side pockets making it difficult to access items unless the strap is loosened. Both packs are heavier than many ultralight internal frame packs that use less rugged fabrics, lighter albeit not as stiff frames, and less padded harnesses.

Specifications

• Backpack Style	Nimbus Ozone – top loading internal frame backpack with roll-top closure Nimbus Latitude – panel loading internal frame backpack
• Fabric Description	70d 2.4 oz/yd2 (81 g/m2) silnylon, reinforced by 210d, 6.5 oz/yd2 (221 g/m2) hybrid HT Cordura in high stress and high wear areas. Both packs feature 8.5 oz/yd2 (288 g/m2) Durastretch fabric on the side pockets. Durastretch is a waterproof / breathable, laminated, stretch woven fabric with DWR surface treatment. The Nimbus Latitude has an additional section of Durastretch between the two panel loading zippers.
• Sizes (Size regular tested in both Nimbus Ozone and Nimbus Latitude)	Sizes Torso Length (in) Torso Length (cm) Short 14-18 36-46 Regular 18-22 46-56
• Volume (Short and Regular volumes are the same for both the Nimbus Ozone and Nimbus Latitude packs)	Sizes Voume (ci) Volume (L) Short 3,500 57 Regular 3,800 62
• Weight (Size Regular tested)	Model Backpacking Light Measured oz (g) Manufacturer Specification oz (g) Nimbus Ozone 48.7 (1381) 48 (1361) Nimbus Latitude 56.8 (1610) 56 (1588)
• Volume to Weight Ratio	Nimbus Ozone – 78 Nimbus Latitude – 67 (based on Regular size volume and Backpacking Light measured weight (ci/oz)
• Load Carrying Capacity	40 lbs (18 kg) as claimed by Granite Gear and confirmed by Backpacking Light
• Carry Load to Pack Weight Performance Ratio	Nimbus Ozone – 13 Nimbus Latitude – 11 (based on Backpacking Light confirmed carrying capacity and Backpacking Light measured pack weight)
• MSRP	Nimbus Ozone – $200 Nimbus Latitude – $230
• Manufacturer’s Contact Information	Granite Gear, 218-834-6157 http://www.granitegear.com

Features

Numerical ratings follow on a scale of 1 to 5 (1=poor, 5=excellent), and are relative to other internal frame packs tested by Backpacking Light.

Frame and Suspension – 4.5

Granite Gear’s Nimbus Ozone and Nimbus Latitude share the same frame and suspension system. Setting these packs apart from the rest of the market is a three dimensionally molded Tepex composite frame (Photo 2). The Tepex frame lacks any similarity to the industry standard, a thin plastic HDPE framesheet and aluminum stays. It resembles a framesheet but is much stiffer, eliminating the need for an aluminum stay. Rather than being stiff just down the center (along an internal stay), the Tepex frame is stiff and supportive throughout. The drawback with this type of frame is that it cannot be shaped to custom match individual back curvature. However, our samples approximated correct spinal shape to keep our reviewers comfortable.

The Nimbus series have harnesses that include shoulder straps, sternum strap, padded hip belt, and shoulder straps and hip belt stabilizers. The padding used in the shoulder straps and hip belt is luxurious. Our female reviewers like its suppleness which distributes loads over a large area and avoids concentrating pressure on high spots (particularly shoulders and collar bones and the top of the hips). Both the shoulder straps and hip belt bolt directly to the Tepex composite frame for a rigid link between harness and pack. The harness attaches to the frame by inserting metal bolts through grommets in the shoulder straps and hip belt that screw into blind bolts behind the Tepex frame. The Tepex frame has been drilled to provide multiple attachment options for the harness. In addition, the shoulder straps have three grommet holes to extend their length and distance apart. The adjustability provided in this arrangement far exceeds that found in other internal frame packs by allowing both torso length and shoulder width adjustments. Note: this adjustment requires a screwdriver that should be carried on a few trips until the fit is dialed in.

Usable Features and Ease of Use – 3.5

Both of these packs have two water bottle sized pockets made of Durastretch fabric at the bottom of the side panels. These easily hold liter-sized bottles. The smooth Durastretch fabric does not hang up on Platypus bag-type bottles. The high position of the side pocket makes access difficult while wearing the pack (e.g. removing a water bottle while hiking). In addition, the lower compression straps cross over the top of these pockets. This makes removing stowed gear almost impossible unless you loosen the strap.

Both packs feature two ice axe loops. The upper shaft of an ice axe in the loop goes underneath the upper side panel compression strap. We had some concern that the axe shafts might abrade the side panel’s 2.4 oz/yd² (81 g/m²) silnylon fabric. So far, we haven’t had any problems in the field.

These packs feature a hydration port and an internal hydration sleeve located against the back panel. A removable shock cord compression system holds the hydration bladder tightly against the back panel. Like most hydration pockets of this design, the contents of the pack must be partially removed in order to refill the bladder. This is a pain on the trail.

Granite Gear’s panel loading Nimbus Latitude has two YKK #8 weather resistant coil zippers running up from the upper back panel, over the top of the pack, and down to the bottom. They are separated by 5-inches (13 cm) of Durastretch material. As the name implies, this material stretches to allow a minimal amount of overstuffing and to reduce the chance of zipper failure. The panel loading design gave us easy access to packed contents. Behind these two panel-loading zippers, Granite Gear has added two internal compression straps mirroring the two on the outside of the pack. These compression straps allow the user to pack the contents of the pack while the zippered panel section is completely open. Once packed, the interior compression straps are tightened making it easier to zip the pack shut. One caveat with this design is an un-sealable 5-inch (13 cm) wide slit at the bottom of the pack, at the lower edge of the Durastretch panel (Photo 3). There is a 4-inch (10 cm) piece of overlapping fabric between the opening and interior of the pack. We explored the possibility of adding Velcro to the bottom of the Durastretch material to secure this opening. However, the designers at Granite Gear avoided Velcro in this area because it will eventually wear out and abrade the fabric it comes in contact with. They also claim to have 10,000 documented miles (16,000 km) with this design without any losses through this opening. We were unable to intentionally make an item fall out with the pack properly loaded and securely compressed.

The Nimbus Latitude has an unusual internal pocket. It is essentially a short, fat stuff sack with a thin piece of perforated closed cell foam supporting the bottom and a draw cord closure. The pocket attaches to the inside of the pack via two small side release buckles. We opted to leave it out during testing in lieu of a stuff sack or two of our own, which proved to better fill the interior volume of the pack and weighed less.

Load Volume Flexibility (Compression) – 5.0

Granite Gear has one of the best compression systems on the market for their Ultralight Packer series. Both the Nimbus Ozone and Nimbus Latitude use two sets of three compression straps that encircle the side panels and back of the packs. The compression straps create two continuous lines of compression over both the upper and lower portion of the packs. These packs can handle compression of full volume loads down to day trip sized loads with ease.

In addition to the horizontal compression straps, the top-loading Nimbus Ozone has a roll-top closure similar to that found on the Granite Gear Virga and Vapor Trail backpacks. Two compression straps cross over each other on the top of the pack, one that provides the roll top closure similar to a dry bag, and the other that provides over-the-top compression similar to compression straps used to secure climbing ropes on alpine packs.

Both the Nimbus Ozone and Nimbus Latitude offer excellent load volume flexibility for long hikes without re-supply or for alpine climbing. For example, we used the Nimbus Ozone as a winter alpine climbing approach pack. The backpack was large enough to accommodate a mountain tent (Integral Designs MK1 Lite), synthetic 20 °F (-7 °C) sleeping bag (The North Face Cat’s Meow), synthetic winter insulating clothing (parka and pants), skis, and other shared climbing and camping gear (including a white gas stove, 2 liter cook pot, ice tools, ropes, and a full rack of slings, ice screws, and pitons) and still left enough room in the extension collar for 4-5 days of food. Upon reaching the base of a climb, the pack compressed very well to remain stable for easy-to-moderate ice climbing in alpine couloirs.

If you need to extend the volume beyond the 3,800 cubic inches (62 L) mark, gear can be attached behind the compression straps on the outside of these packs (Photo 4). The Granite Gear Nimbus Latitude excels here as the compression straps crossing the back of the pack are connected with side release buckles (a necessity for the panel access) and can be opened to readily accept gear. The Nimbus Ozone, on the other hand, uses ladder locks in this location requiring items to be slipped into position from the top.

Because the Nimbus Latitude is a panel loading pack, it lacks the additional storage provided by an extension collar. Granite Gear’s Nimbus Ozone has a short extension collar at its upper opening.

Field Performance

Pack Load Carrying – 4.5

Backpacking Light’s testing confirms the load carrying performance of the Nimbus Series meets Granite Gear’s claim of 40 pounds (18 kg). Although we were regularly able to carry more than forty pounds in the pack with no ill effects, many testers had hipbelt discomfort with loads of 45 pounds (20 kg) and higher. We fitted the pack to several people in the recommended torso size range (men and women) and found that the contoured and shaped hip belt did not perfectly fit everyone’s body type. Perhaps a flatter (not pre-molded/contoured), thinner (and thus, more likely to conform to people’s hip shapes), but wider (to increase load bearing surface area) hip belt would carry loads as well and increase comfort for a wider range of body types.

For three out of five testers, carrying loads higher than 45 pounds (20 kg) for more than 10 miles (16 km) a day caused some pain in the iliac crest area. The cause of the pain was the collapse of the hip belt under heavier loads. The belt no longer spread the pack’s load evenly across the hips but concentrated pressure at the top of the iliac crest, which resulted in substantial discomfort. Thus, we estimate the reasonable “long-distance” load carrying capacity of the Nimbus Ozone and Latitude to be about 40 pounds (18 kg), consistent with Granite Gear’s claim.

Durability – 3.5

Due to the use of 2.4 oz/yd² (81 g/m²) silnylon in areas that are prone to abrasion, including the lower back panel, upper side panels, and extension collar (Nimbus Ozone only), the Ozone and Latitude have some durability limitations. Increasing the height of the bottom reinforcing fabric a few inches would protect the lower back panel. If you are using the extension collar on the Nimbus Ozone, its light fabric will be exposed while bushwhacking or scrambling. Most other backpacks which use similarly light extension collar fabrics have a top lid that generally protects the collars from abrasion. Granite Gear might consider offering a modular top “flap” or an extension collar using more durable fabric to decrease the extension collar’s vulnerability to abrasion.

The Nimbus Latitude, which doesn’t have an extension collar, does have the heavier weight hybrid Cordura and Durastretch material on its top. Wear in this area from bushwhacking is not as much of a concern. However, the upper side panels, made of 2.4 oz/yd² (81 g/m²) silnylon are exposed in both of these packs (Photo 5). This area is susceptible to abrasion while bushwhacking, and care must be taken to avoid damage.

The side pockets are not durable enough to withstand repeated stowage of metal-edged skis; we found the pockets had holes from ski edges after only a few days of hiking with skis in the pockets. This problem was alleviated by inserting ski tails first into some custom-sewn Cordura sleeves prior to stowing them in the pockets.

Value – 3.5

At $200 and $230 for the Nimbus Ozone and Nimbus Latitude respectively, these packs are not exactly inexpensive. However, they offer a comfortable carry, top-notch construction and materials, and are reasonably light for packs capable of carrying the weight and volume these packs can haul. Attributes that downgraded the value rating include the inaccessible side pockets and unprotected, less durable fabric in highly exposed areas.

Recommendations for Improvement

A few recommendations: first correct the conflict of the lower side-panel compression straps limiting access to the side pockets. One solution would be to run the compression straps behind each pocket. One could do this by adding two small slits along the sides of the pockets so that the compression straps would run through and underneath the pocket. Adjusting the compression straps would become more cumbersome; however, this is usually done with the pack off and would be easier than trying to get a water bottle back into the pocket while moving in the current configuration. If one was concerned with the lower opening on the Nimbus Latitude’s Durastretch panel access, a small amount of sewing skill and a bit of Velcro could easily seal this opening during the hike while maintaining access to the zippered panel.

Overview

The Granite Gear Vapor Trail uses a flexible high-density polyethylene (HDPE) framesheet in combination with a virtual frame to transfer the load to your hips. When packed with 30 pounds (14 kg) or less, the harness design, frame sheet, compression strap system/virtual frame, and load lifter straps work well together to create a comfortable carry. Our primary reviewer found the Vapor Trail pack to be very comfortable and more amenable to the female body than most ultralight packs. In the past, other internal frame packs have bruised her hips and pulled at her shoulders. The flexible HDPE plastic framesheet strikes a compromise between light weight and flexibility to move with your torso but still provide enough ‘frame’ to transfer load to your hips when the pack is fully compressed.

The Vapor Trail has one of the best external hydration pockets we’ve seen on a pack. It doesn’t take away pack volume, sits close to your back for balance, and you can remove the bladder without opening the pack or removing any gear!

The Granite Gear Vapor Trail is made with more rugged fabrics than many packs in its weight class, with substantial fabric reinforcements in the abrasion-prone areas of the pack’s bottom panel, lower sides, and rear panel. The Vapor Trail is suitable, both in load carrying capability and features, for backpacking, off-trail scrambling, and alpine climbing. Major weaknesses of this pack include shoulder strap attachment points that are too low on the backpanel, contributing to poor load lifter strap performance when the pack is under packed, and limited external pocket storage for commonly accessed items. Admittedly, climbers and minimalists may love the pack’s current pocket configuration.

Specifications

• Backpack Style	internal frame pack (framesheet), top-loading with roll-top closure.
• Fabric Description	210d, 6.5 oz/yd2 (221 g/m2) Cordura nylon/polyester blend in high stress (shoulder strap and compression strap attachments) and high wear (rear pack panel, bottom of the pack) areas; 70d 2.4 oz/yd2 (81 g/m2) silicone coated nylon in the packbag. 8.5 oz/yd2 (288 g/m2) Durastretch (four way stretch nylon) on side pockets.
• Sizes (Size Short tested)	Sizes Torso Length (in) Torso Length (cm) Short 15-18 38-46 Regular 18-21 46-53 Long 21-25 53-64
• Volume (Size Short tested)	Sizes Volume (ci) Volume (L) Short 3,300 54 Regular 3,600 59 Long 3,900 64
• Weight (Size Short tested)	Sizes Backpacking Light Measured oz (g) Manufacturer Specification oz (g) Short 32.2 (921) 30 (850) Regular Not measured 32 (907) Long Not measured 34 (964)
• Volume to Weight Ratio	102 ci/oz (based on 3300 ci and a measured weight of 32.2 oz)
• Load Carrying Capacity	35 lbs (16 kg) is a reasonable limit for the average user if a good virtual frame is used to supplement the framesheet. It may be pushed to as much as 40 lbs (18 kg) for hikers who find weight on their shoulders tolerable. Granite Gear claims 30 lbs (14 kg).
• Carry Load to Pack Weight Performance Ratio	17 (based on 35 lbs and a measured weight of 32.2 oz)
• MSRP	$150
• Manufacturer’s Contact Information	Granite Gear, 218-834-6157 http://www.granitegear.com

Features

Numerical ratings follow on a scale of 1 to 5 (1=poor, 5=excellent), and are relative to other internal frame packs tested by Backpacking Light.

Frame and Suspension – 4.0

The Vapor Trail’s anatomically curved shoulder straps are more padded (0.5 in, 1.2 cm thick) than those found on many lightweight internal frame packs. With the pack properly loaded and compressed, the load lifter straps pull the pack close to your back for optimal pack stability and balance while hiking or scrambling on rough terrain. Shoulder straps are attached to the top of the frame sheet but well below the top of the pack and the load lifter straps attachment points. In our opinion, the shoulder straps are attached too low and negate the ability of the load lifter straps to maintain stability (tension) in the upper portion of the pack when the upper portion of the pack is not tightly packed and compressed. Fortunately, this problem can be alleviated in large part by properly adjusting the upper compression system so the section between the top of the frame sheet and the load lifter attachment points is rigid.

We found the well padded, 4 inch (10 cm) wide and 7/8 inch (2 cm) thick, hipbelt provided good load transfer to our hips for loads of up to 30 pounds (14 kg), providing the pack’s compression system was properly used to create a virtual frame to supplement the somewhat flexible framesheet’s performance. Ultralight hikers, who are used to minimal or no hipbelts, will appreciate the well-padded belt found on the Vapor Trail.

The Vapor Trail’s soft foam back panel padding and padded ergonomic harness are more comfortable than those used in many ultralight framed backpacks, especially those in the 2 pound (0.9 kg) range. Alison, the lead tester for the Vapor Trail, found the well-padded hipbelt exceptionally comfortable on her bruise-prone hips. The 2.5 inch wide (6 cm) and 1/2 inch thick (1.2 cm) anatomically curved and padded shoulder straps are a boon to sensitive shoulders as pack weight increases and more weight inevitably gets transferred to the shoulders.

Usable Features and Ease of Use – 3.5

Granite Gear’s Vapor Trail has features that will appeal to hikers and climbers alike. The Vapor Trail has Durastretch side pockets that, when used in combination with side compression straps, are suitable for long, skinny items like tent poles, a fishing rod, trekking poles, or snow anchors. The side pockets are capable of carrying 1-liter water bottles. However, they are covered by the lower side panel compression straps, making it quite a feat to remove and replace a water bottle while wearing the pack. The rear compression straps are ideal for holding bulky and large items like a wet tarp or an additional sleeping mat (e.g., on a snow trip).

The Vapor Trail has most of the features one would want in an off-trail and alpine climbing backpack – durable fabric in high wear areas, dual tool loops, a reasonably slim profile for good balance and arm swing clearance, large capacity, a versatile compression system, and easy climbing rope attachment using the top and side compression straps. When the Vapor Trail was properly packed with a full load, we found its load control and pack stability were excellent for off-trail scrambling, bushwhacking, and climbing.

The Vapor Trail has an additional pocket behind the padded backpanel, accessible from the outside, that will accommodate a full three-liter Platypus bladder comfortably. This setup is one of the best hydration pockets we’ve used, allowing easy access to a bladder without unpacking or opening anything. The water is held close to your back for good balance and is insulated by the foam backpanel and pack contents. This excellent, albeit unintentional, hydration pocket significantly improves the pack’s rating in this category. In addition, it leaves the side pockets free of water bottles and available for storage of other items.

Load Volume Flexibility (Compression) – 5.0

The Granite Gear Vapor Tail’s effective compression system controls loads of almost any size, keeping even day-sized loads stable. With eight compression straps, and two catenary compression panels, the Vapor Trail’s ability to stabilize a load in unmatched by most internal frame backpacks on the market. The dual top closure straps compress the top of the pack effectively, playing an essential role in maximizing the effectiveness of the shoulder strap load lifters.

Field Performance

The Vapor Trail was tested in the High Sierras, the Blue Ridge Mountains of the Northeast, and along the Ice Age Trail in the Midwest. Conditions encountered included difficult off-trail travel over rock, ice, snow, scree slogs, and some serious bushwhacking.

Pack Load Carrying – 3.5

Granite Gear rates the Vapor Trail load carrying capacity at 30 pounds (14 kg). With its sturdy hip belt, well-padded and ergonomic harness, and combination framesheet/virtual frame, the Vapor Trail handles 30-pound (14 kg) loads with ease. If one can tolerate a bit of weight on their shoulders, and a good virtual frame has been created, 40 pounds (18 kg) can be carried without too much discomfort. Overall, we estimate that 35 pounds (16 kg) is a reasonable limit for the average user if a good virtual frame is used to supplement the framesheet.

The Vapor Trail’s compression system can compress the packbag to create a nearly rigid pack enhancing the framesheet’s performance and efficiently transferring the load between shoulders and hips. Pulling the pack tight to the back allows for excellent load control and wearer balance when carrying loads up to 30 pounds.

Durability – 3.5

The only thing holding the Granite Gear Vapor Trail back from a higher durability rating is the use of silicone coated nylon fabric in the pack body. Even so, fabric reinforcements in key areas make the Vapor Trail suitable for alpine scrambling and bushwhacking in conditions where you won’t constantly drag your pack against sharp rock or plow pack-first into groves of slide alder. The Granite Gear Vapor Trail uses a more tear and abrasion resistant 2.4 oz/yd² (81 g/m²) silnylon as compared to the more common 1.3 to 1.7 oz/yd² (44 – 58 g/m²) fabrics used by other manufacturers. Cordura (6.5 oz/yd², 221 g/m²) is used in high wear areas, such as the bottom, back panel, and much of the rear panel. The Durastretch side pockets protect the silnylon on the lower side panels. Still, the pack has some of the lighter fabric exposed, and as strong as it is relative to lighter silicone coated nylons, it won’t withstand repeated abrasion.

Value – 4.0

At only $150 we think the Granite Gear Vapor Trail is a good value. For its weight, the Vapor Trail provides efficient load transfer to the hips, offers a comfortable harness, is durably constructed, and offers a versatile compression system suitable for a wide range of load sizes. The Vapor Trail’s durability, climbing friendly amenities, stability, and minimalist design will appeal to aggressive off-trail travelers and fast and light climbers who don’t overly abuse their packs. We especially like the Vapor Trail’s external hydration pocket.

Recommendations for Improvement

• The Vapor Trail’s lower compression straps run over the top of the side pockets. If you have these compression straps tightened down, you’ll need to loosen them to access pocket contents, a nearly impossible task to perform while hiking. We suggest moving these straps up to clear the top of the pockets.
• The lower portion of the pack is prone to abrasion (e.g., sliding down a steep slope) and would benefit from tougher fabric in the region below the lowest compression straps.
• While adaptable to a wider range of torso sizes than other frameless packs, the Granite Gear Vapor Trail’s shoulder strap-and-load-lifter system is quite sensitive to torso collapse when the pack is under-loaded or improperly packed, making the Vapor Trail more appropriate for lightweight hikers who pay a reasonable amount of attention to packing their pack. Extending the frame sheet to the top of the pack and raising the shoulder strap attachment points would increase the pack’s load carrying capacity.
• In lieu of the solid side pockets, we’d prefer to see mesh pockets that better expand and contract to different volumes and allow us the capability to see what is in the pockets.

Overview

The Mountainsmith Auspex is a top-loading internal framed pack offering extensive options and exceptional load carrying capability at a lighter weight than many of its competitors. While there are many packs that weigh less than the 4.1 pound (1.85 kg) Auspex, you will be hard-pressed to find one with as many features – convertible top lid, tough abrasion-resistant fabrics, an innovative bungee system, hydration system capability, water-resistant zippers, side panel access, and the ability to carry 65 pounds (30 kg). If you are a 20 pound (9 kg)-carrying fastpacker, the Auspex will be way more than you need or want. The Auspex is a light expedition worthy pack that is also ideal for climbing or mountaineering.

Specifications

• Backpack Style	Internal frame, top-loading with side panel zipper access.
• Fabric Description	Pack body constructed of Dimension Polyant x-Pac VX-21 and VX-42 fabrics that utilize a 3-ply design with a grid of high tenacity fibers in the middle (somewhat like Spectra). High tenacity nylon is used for the bottom and other high wear areas. Breathable Brock foam and nylon mesh are used at contact points for moisture transport.
• Sizes (Size LT tested)	Sizes Torso Length (in) Torso Length (cm) LT 19-22 48-56 MT 17-19.5 43-50 Chimera (Women) 15-17 38-43
• Volume (Size LT tested)	Sizes Volume (ci) Volume (L) LT 4,000 66 MT 3,850 63 Chimera (Women) 3,600 59
• Weight (Size LT tested)	Sizes Backpacking Light Measured oz/yd2 (kg) Manufacturer Specification oz/yd2 (kg) LT 65.3 (1.85) 64 (1.81) MT Not measured 63 (1.79) Chimera (Women) Not measured 58 (1.64)
• Volume to Weight Ratio	61 ci/oz/yd2, size LT (based on 4,000 ci and Backpacking Light measured weight of 65.3 oz/yd2)
• Load Carrying Capacity	60-65 lbs (27-30 kg) as estimated by Backpacking Light.
• Carry Load to Pack Weight Performance Ratio	16 (based on 65 lbs and Backpacking Light measured weight of 65.3 oz/yd2)
• MSRP	$230
• Manufacturer’s Contact Information	Mountainsmith (800) 551-5889 http://www.mountainsmith.com

Features

Ratings follow on a scale of 1 to 5, with 5 being the best, and are relative to other Backpacking Light tested framed packs.

Frame and Suspension – 4.5

The Auspex pack utilizes Mountainsmith’s Mountainlight suspension system. This system consists of two corrugated aluminum stays, a plastic mid-panel framesheet, padded shoulder straps, and a wide padded hipbelt. The stays are exposed in the lower section of the pack, and the hipbelt and upper shoulder pads are the only body contact points (Photo 2). The back panel is much more airy than a traditional full-contact design. Brock foam and nylon mesh, used for the shoulder and hipbelt padding, transports moisture and keeps the pack dry against your skin, even when worn without a shirt.

Side compression straps and a back bungee work together to keep loads compact. With the Auspex properly loaded and compressed, the load lifter straps and hipbelt stabilizers pull the pack close to your back for optimal pack stability and balance when hiking or scrambling on rough terrain. Torso length can be adjusted by moving the shoulder straps up or down along the two exposed corrugated stays. The sternum strap adjusts vertically along a unique piping channel, which offers no technical advantage but looks great. Stays are removable, but it is not an easy task. The user will most likely remove them once for bending and then leave them in the Auspex. It is essential to properly adjust the exposed stays to your back; one reviewer felt the non-adjusted stays jam into his back (Photo 2) on an extended hike. Another repeatedly hit his elbow when donning the pack at first, but then adjusted to the design.

Usable Features and Ease of Use – 4.5

The Auspex is full of many usable features often found in much heavier packs. It has a floating top lid with two pockets. The top pocket has a water-resistant zipper and is accessible while wearing the pack. Another pocket, hidden underneath the top hood, is constructed of mesh for easy viewing of the contents and includes an internal key clip. The top lid converts to a convenient fanny pack for day tripping (Photo 4).

Convenient side pockets hold items such as a wind shirt or water bottle securely and are protected by high-tenacity nylon on the bottom for durability. The side pockets are easily accessible while wearing the pack. The Auspex is hydration system-friendly with a removable internal hydration sleeve and shingled exit ports on each side of the pack body. Elastic loops integrated into the shoulder straps keep hydration hoses secured and within easy reach. A water-resistant panel loading side zipper allows access to items inside the main body of the pack; however, our reviewers found it easier to access items through the top as the water-resistant coating makes the zipper stiff. The Auspex includes two ice-axe loops at the bottom of the pack’s back.

Although these features make the Auspex usable over a wider range of backcountry adventures, the added features increase the pack’s weight. The typical lightweight backpacker will find these features get in the way more often than they are needed.

The shock cord on the back of the pack is quickly removable from the side attachments making it easy to attach large objects, such as sleeping pads or tents, without the need to feed the items through a web of cords (Photo 5). Simply remove the cord attachments from one side, center the object on the pack, reattach the cords, tighten the one-handed cord lock, and the hiker is ready to go.

Load Volume Flexibility (Compression) – 4.0

The Auspex’s effective compression system allows it to comfortably carry loads much smaller than the maximum capacity. By tightening the side compression straps, tightening the bungee system, and leaving the top lid empty, the user can comfortably carry even day-sized loads with great stability. Because the aluminum stays are difficult to remove, the Auspex remains tall and stiff while carrying these minimal loads. With large volume loads, the exterior side pockets, top lid pocket, and shock cords across the back provide suitable expansion of an already large (by lightweight standards) pack.

Field Performance

Pack Load Carrying – 5.0

The Auspex can haul heavy loads with ease. During one field session on the badly washed out Enchanted Valley trail in Olympic National Park, a reviewer carried both his and his wife’s loads (approximately 35 lbs, 16 kg) in complete comfort. In an effort to find the pack’s carrying limit, the pack was filled with 50 pounds (23 kg) of water and rocks . Even with the rough terrain, the Auspex did not flex and carried the weight comfortably. In further tests, the pack was filled with 65 pounds (30 kg) of water and weights and taken for several miles on local trails. The Auspex carried this load comfortably. We think it could probably carry even more. Through the full range of loads carried, the wide hip belt and high-density foam shoulder straps transferred the weight as comfortably as packs weighing much more. The Auspex is a true expedition worthy load hauler. In addition, its compression system and slim pack design kept the load close to the user’s back for a good center of gravity.

Durability – 5.0

After extensive use, Mountainsmith’s Auspex only showed slight fraying in the piping that frames the base of the pack. All straps are internally sewn into piping which is very strong. The use of highly abrasion-resistant Dimension Polyant x-Pac fabrics enables the Mountainsmith pack to hold up well, even in off-trail hiking and climbing. Heavier high-tenacity nylon is used on the bottom of the pack for further durability in this high wear area.

The reinforced x-Pac fabric used behind the bungee made it possible to carry crampons without a reinforced bag. This narrow, durable pack makes an excellent companion for climbing trips.

Value – 4.0

At $230, the Auspex is not an inexpensive pack. However, you are getting all the bells and whistles such as waterproof zippers, convertible top lid/fanny pack, bungee system, durability, side access, high tech fabrics, and a suspension system that can handle expedition weight loads. Further, this is accomplished at just a hair over 4 pounds (1.85 kg). As a lightweight expedition pack, the Auspex is an excellent value.

Recommendations for Improvement

Mountainsmith has hit their target market quite well with the Auspex pack. While not as light as some other packs, you would have to eliminate features and durability to bring the weight down; this is simply not Mountainsmith’s goal with this pack. Our only concern with the Auspex is the exposed frame stays. During testing, we repeatedly scraped our triceps against the sharp stay edges, especially when the pack was filled to capacity. A better design would have the stays covered in soft fabric or at least sanded smooth along the edges.

Overview

The Gossamer Gear (formerly GVP Gear) Mariposa represents a significant step forward in the ultralight backpacking industry; a 1-pound (0.5 kg) pack capable of carrying loads up to 30 pounds (14 kg) in reasonable comfort. Gossamer Gear does this without losing features like full peripheral pockets, padded hip belt, bear canister compatibility, and an ice axe loop (Photo 1).

The key to this carrying capacity: two carbon fiber stays combine with the hiker’s sleeping pad to form a rigid frame that effectively transfers pack weight to the hipbelt. Another innovation is the use of pad pockets on the shoulder straps and hip belt that permit exchanging the included closed cell foam pads with articles of clothing, thus leaving the padding weight at home. Further weight is reduced by the use of 1.3 oz/yd² (44 g/m²) silnylon for most of the pack body (oxford cloth is used in key stress/wear areas). Obviously, a pack made of such lightweight material is not designed to handle the rigors of off trail backpacking and climbing. One gripe: the harness on the prototype Mariposa tested was not a great fit. We’ve talked with Gossamer Gear and expect a few tweaks will significantly improve comfort on production packs.

Specifications

Backpack Style	Internal frame, top-loading pack with roll-top closure
Fabric Description	40d 1.3 oz/yd2 (44 g/m2) silnylon and selected use of 210d 4 oz/yd2 (136 g/m2) urethane-coated ripstop nylon
Sizes (Size M tested (prototype))	Sizes Torso Length (in) Torso Length (cm) S 16-19 41-48 M 18-22 46-56 L 20-24 51-61
Volume (Size M tested (prototype))	Sizes Volume (ci) Volume (L) S,M,L 4,200 69
Weight (Size M tested (prototype))	Component Measured Weight oz (g) Manufacturer Specification Weight oz (g) Pack complete 17.0 (482) 17.4 (493) Pack stripped 14.9 (422) 14.6 (414) Stays 0.9 (26) pair 0.8 (23) pair Hip belt pads 0.3 (9) pair 0.4 (11) pair Shoulder pads 0.4 (11) pair 0.4 (11) pair Sternum strap 0.5 (14) 0.5 (14)
Volume to Weight Ratio	247 ci/oz size M (Based on 4,200 ci, size M, and Backpacking Light measured weight of 17.0 oz)
Load Carrying Capacity	30 lbs (13.6 kg), maximum comfortable carrying capacity as determined by Backpacking Light. Manufacturer claims 40 pounds (18.1 kg) maximum carrying capacity and Backpacking Light agrees the Mariposa will carry it, but with reduced comfort and with greater concern for fabric failure.
Carry Load to Pack Weight Performance Ratio	28 (based on 30 lbs and Backpacking Light measured weight of 17.0 oz)
MSRP	approximately $140, price not set at time of review
Manufacturer’s Contact Information	Gossamer Gear, 877-ULTRA-LT, http://www.gossamergear.com

Features

Ratings follow subtitles on a scale of 1 to 5, with 5 being the best, and are relative to other Backpacking Light tested internal framed packs.

Frame and Suspension – 3.5 (pre production) 4.0 (if production changes made)

Gossamer Gear’s Mariposa uses an innovative frame and suspension setup to comfortably carry loads up to 30 pounds (13.6 kg) in a pack weighing just a shade over 1 pound (0.5 kg). Currently, only two other pack manufacturers are employing similar frame designs (Six Moon Designs Starlite and ULA Fusion). The Mariposa integrates the user’s sleeping pad with two hollow carbon fiber frame stays to create a rigid back panel. The pack’s pocketed back panel has an opening slit in the center, where a sleeping pad is inserted, first into the bottom half and then into the top. Most thin 3/4-length closed cell foam (i.e. RidgeRest or Z-Rest) or any length rectangular, self-inflating pads should fit. This pocket measures 11 inches wide by 20 inches high (28 x 51 cm). If a self-inflating pad is used it has to be inflated before inserting, as there is no opening in the pocket to gain access to the valve. Inserting a sleeping pad into this pocket is slightly cumbersome, but the design is extremely light and simple.

The two carbon fiber stays look similar to carbon arrow shafts, but are nicely finished on both ends with a dome-shaped aluminum cap. The shape and smoothness of the caps prevent inadvertent fabric wear within the stay sleeves; an important consideration in such a light-fabric pack. The stays are easily removable by opening the Velcro closure at the tops of each stay pocket. It is not possible to reshape them, though the sleeping pad tends to conform to one’s back shape to some extent.

The back panel/pad pocket material is mesh. This material is thin and the portion of the sleeping pad, between the upper and lower sleeves is directly against the user’s back. The type of sleeping pad selected will determine pack comfort while on the trail. Closed cell foam pads that contain ridges and valleys offer some additional breathability over the self-inflating types, a relief when hiking in hot weather.

The Gossamer Gear’s harness sets it apart from most lightweight packs. Upon first inspection it appears simple, but this belies a sophisticated design. You can use gloves, socks, or other articles of clothing to replace the closed cell foam inserts (included) in the shoulder straps and hipbelt. This saves the weight of the foam padding and even gives you some extra pack room.

The Mariposa has a removable sternum strap with a safety whistle. Both the shoulder straps and hipbelt are sewn onto the back panel. Thus, the harness does not adjust to accommodate varying torso lengths. It also lacks shoulder strap and hip belt stabilizers. Unnoticed initially are Velcro openings along the seams of both the shoulder straps and hip belt, which allow the user to remove the padding to save weight. My first unfounded concern was that my clean socks were going to get soaked with sweat before I had an opportunity to wear them. However, a layer of 1.3 oz/yd² (44 g/m²) silnylon lines the inside of these pockets to keep the contents dry. In addition, the shoulder straps are a whopping 3.5-inches (9 cm) wide at their contact point. With lighter loads, many users will find the padding unnecessary. I was also concerned that articles of clothing used to replace the closed cell foam would not provide enough padding for comfort. Because the shoulder pads are so wide, the “padding” need only spread out the shoulder straps and keep them wide (Photo 2). In our testing, a shoulder strap without any padding would curl and become narrower, concentrating the pack weight on a smaller area and increasing discomfort. However, with as little as a thin polypropylene balaclava, the straps would maintain their full width and evenly distribute the load. Care must be taken to insert and remove clothing items without snagging them on the Velcro openings. You can also put the item in a light baggie to solve this problem and keep the article extra dry.

The fit was not perfect with our “pre-production, prototype” Mariposa. While the fit of the prototype will be discussed here, we have spoken with Gossamer Gear to learn others have expressed similar concerns with the prototypes and production runs will be corrected. With that said, the hip belt is sized fairly large on the size Medium prototype tested. With the padding removed, the hip belt was too big for my 33-inch (84 cm) waist. Even with the foam pads inserted, the adjustment straps would bottom out before the hip belt was completely snug. Production runs will have a slightly shorter hip belt (padded portion), which will alleviate this concern. Also, the webbing that the sternum strap adjusted on was too high. Referring to Photo 2, the sternum strap is at the bottom of the adjustment webbing, which is attached to each shoulder strap. Notice that the strap is well above the center of the wearer’s chest with nowhere to adjust but up to the neck. Again, production models should be corrected in this area.

Usable Features and Ease of Use – 4.0

Even at 17.0 oz (482 g), the Gossamer Gear Mariposa is still a full-featured pack. It has a total of four external nylon mesh pockets, not including the pad pocket and harness padding pockets. The pockets serve two purposes-to provide convenient storage and retrieval of frequently needed items and to protect the lower portion of 1.3 oz/yd² (44 g/m²) silnylon making up the pack body. The lower back is covered with a large pocket suitable for storing wet tarps and the like. On the left side panel, a long 13-inch (33-cm) pocket provides enough room for a 2-liter water bladder. There are two pockets to protect the right side panel, one above the other. The lower 1-liter water bottle pocket is easily accessed while wearing the pack. A thinner map and compass sized pocket is above that.

The pre-production sample received for this review did not include the internal hydration pocket that will be found on production models. The hydration pocket will be constructed out of 1.3 oz/yd² (44 g/m²) silnylon, be non-removable, and will include two drinking tube ports. Since it is going to be made of silnylon, we don’t expect it to add much weight (approximately 0.2 oz, 6 g).

The back pocket is covered by a removable shock cord, which provides some minimal compression and an additional location for storing wet gear. The shock cord is laced through grosgrain attachment points located along both vertical seams on the back. These attachments points are repeated down each vertical seam on either side of the back panel, at the front of the side panels. These offer additional gear securing options and because they are tied into the 210 denier nylon oxford fabric, they are a more durable attachment point. These can be used to attach the tops of long items (trekking or tent poles) that are inserted into the side pockets, as an additional location for compression shock cords, or as a convenient location for one’s bandana or towel. Use your imagination.

For those who like to venture over ice and snow, a single ice axe loop is centrally located below the large back pocket. It could also be used as a place to attach adjustable trekking poles. When the back pocket is full, items attached to this loop are pushed away from the pack by the pocket contents. Attachment for other climbing hardware is not provided. A single haul loop is included between the shoulder straps.

The top of the Mariposa closes like a stuff sack, with a draw cord closure. The top of the pack is then secured with a Y-shaped compression strap. This grosgrain-webbing strap attaches at the top of each shoulder strap and extends all the way to the bottom of the large back pocket. In addition to compressing the pack, its wider profile across the top provides storage for larger items, like a bear canister, that might sit on top of the pack.

Load Volume Flexibility (Compression) – 2.5

The Gossamer Gear Mariposa can adjust to varying volume loads, though this is not its strong suit. To adjust to smaller loads, the contents initially stored in the mesh exterior pockets can be brought to the inside and the single top compression strap tightened. This, combined with tightening the back shock cord, is the only means of converting this pack to daypack dimensions. Heavier items will tend to stretch out the shock cord rendering compression less effective. Because of the limited number of compression straps, the fully compressed Mariposa looks lumpy. Very small volumes do not compress well to the point of having loose contents in the pack. Larger loads that exceed the pack body’s 2,900 cubic inch (48 L) main volume, can overflow into the 500 cubic inch (8 L) mesh pockets and 800 cubic inch (13 L) extension collar, with the remaining gear attached using various shock cord arrangements, before resorting to hand carrying gear.

Field Performance

Pack Load Carrying – 4.0

The Mariposa was tested while carrying weights ranging from 15 to 40 pounds (7 to 18 kg). We tested it both properly loaded approaching full volume, and with small volume, dense loads (i.e. water hauling trips). Although Gossamer Gear rates this pack as able to carry 40 pounds, we find this weight pushes the limits of the Mariposa. Here we evaluate the comfort of the different suspension components, as some hikers will have higher tolerances for discomfort in different areas. With the foam padding inserts, the shoulder straps and hip belt can comfortably carry up to 35 pounds (16 kg). It would seem replacing the foam padding with articles of clothing would greatly reduce the carrying comfort. Actually, the wide 3.5-inch (8.9 cm) straps dissipate the pack weight so well they only need enough “padding” in them to maintain their wide shape. Thus, with articles of clothing filling the shoulder straps and hip belt, we feel they are still comfortable supporting pack loads of up to 35 pounds. The frame stays remain solid up beyond 40 pounds and are not contributors to discomfort. Although the frame stays remain stiff at 40 pounds, the sleeping pad does not. Beginning at 30 pounds (14 kg), and after several miles, we find the sleeping pad within the Mariposa’s back panel collapses a bit and bulges in a way that does not complement the shape of one’s back. While we found it uncomfortable, it was not a level of discomfort that made carrying the pack miserable. It is appropriate to state that the Mariposa is capable of carrying weight upwards of 40 pounds for short legs of a trip where extra water or food is needed. Nevertheless, we found this pack performs best with weights at or below 30 pounds.

The Mariposa does not have a compression system that fully compresses and controls small, heavy loads. This pack’s ability to stabilize this type of load was exceeded at weights above 15 pounds (7 kg). Therefore, while short trips for water are acceptable with this pack, using it as a daypack or for a summit push may not be appropriate. Gossamer Gear did not design the Mariposa with carrying small, heavy loads as a requirement.

Durability – 2.0

A tradeoff with most lightweight packs is fabric durability. Gossamer Gear’s Mariposa is no exception; however, design elements are in place to minimize the 1.3 oz/yd² (44 g/m²) silnylon fabric from exposure to fabric destroying elements. Both the bottom and back panel of the Mariposa are covered by the relatively more durable 210 denier coated oxford. These areas are exposed to abrasion from the ground and fabric stress from the harness and internal stays. The silnylon, which is used for both side panels and the back, is partially protected by the nylon mesh pockets from the bottom of the pack up to 13-inches (33 cm) high. Assuming these pockets are completely empty, the silnylon can possibly be damaged through the mesh but to a limited extent. The real vulnerable areas are on the upper back and side panels above the 13-inch high pockets. Low branches can wreck havoc on the upper end of this pack.

This pack is not well suited as a climbing pack or for off-trail bushwhacking. Frequent contact with rock, trees, and other abrasive surfaces will eventually cause fabric failure. This was not the intended purpose of the Gossamer Gear Mariposa, which was designed to meet the needs of long distance trail hikers interested in reduced weight. If you are looking for a lightweight climbing pack, this is not it.

Value – 3.5

Considering the weight of the Mariposa, you don’t get much for your money, and we like that. Although higher priced than most silnylon packs, the price reflects innovative design and quality construction. You probably won’t find another 1-pound pack with the features of the Mariposa that can comfortably carry 30 pounds or more. The Mariposa value was slightly downgraded due to its lower durability; though this is the tradeoff for its reduced weight.

Recommendations for Improvement

When the back pocket is filled with gear and bulges out, trekking poles or an ice axe attached to the centered ice axe loop at the bottom of the back pocket tend to stick out rather than ride close to the pack. Relocating the ice axe loop to either side of the back would fix this problem. We also expect to see corrections to the hip belt (which was too long) and the sternum strap (which was too high) when full-production packs hit the market. We do not wish to see any improvement to durability, as this would also increase the weight. There are plenty of light, durable packs on the market. The incredibly light, not-so-durable Gossamer Gear Mariposa is a needed extremity to satisfy those on the lightweight fringe who spend most of their time hammering out long miles on the trail.

Overview

The Gregory G Pack is the result of Gregory’s experience making comfortable packs applied to lighter fabrics and materials. The hollow core single aluminum stay and well fitting harness combine to create a very comfortable pack suspension without being overly stiff. Weights at or around 30 pounds (14 kg, Gregory’s suggested weight) carried very comfortably in the G Pack. However, Gregory’s G fabric (1.3 oz/yd², 44 g/m² silnylon) is rather thin and will not handle a lot of abuse. We also found the lack of accessible pockets, limited exterior attachment options, and the omission of hydration compatibility disappointing.

Specifications

• Backpack Style	Top loading internal frame with top lid pocket closure.
• Fabric Description	Silicone impregnated 30d, 1.3 oz/yd2 (44 g/m2) “G fabric” for the main body and 210d, 4.8 oz/yd2 (163 g/m2) HT ripstop nylon for high wear areas and reinforcements.
• Sizes (Size M tested)	Sizes Torso Length (in) Torso Length (cm) S 15.5-17.5 39-44 M 17.5-19.5 44-50 L 19.5-21.5 50-55
• Volume (Size M tested)	Sizes Volume (ci) Volume (L) S 2,650 43 M 2,900 48 L 3,100 51
• Weight (Size M tested)	Sizes Backpacking Light Measured oz(g) Manufacturer Specification oz(g) S Not measured 41 (1,162) M 43.6 (1,236) 44 (1,247) L Not measured 46 (1,304)
• Volume to Weight Ratio	67 ci/oz, size M (based on 2,900 ci and Backpacking Light measured weight of 43.6 oz)
• Load Carrying Capacity	30 lbs (14 kg) as estimated by Backpacking Light
• Carry Load to Pack Weight Performance Ratio	11 (based on 30 lbs and Backpacking Light measured weight of 43.6 oz)
• MSRP	$149
• Manufacturer’s Contact Information	Gregory (800) 477-3420 http://www.gregorypacks.com

Features

Ratings follow subtitles on a scale of 1 to 5, with 5 being the best, and are relative to other Backpacking Light tested framed packs.

Frame and Suspension – 4.5

Gregory lightened the G Pack by reducing fabric weight while retaining a fairly substantial frame and harness for a pack designed to carry 30 pounds (14 kg). The frame consists of a single hollow core 7075 series aluminum internal frame stay and a supportive HDPE plastic framesheet (Photo 2). Although Gregory describes the frame sheet and stay as removable, removal is very difficult and not a task that one would repeat often. The one time I accomplished the task, it took me 15 minutes, and I broke out in a sweat. Nevertheless, once removed, the stay can be bent to make minor adjustments to better match spinal curvature.

The Gregory G Pack has padded shoulder straps and hipbelt, both cushioned sufficiently for the load carrying capacity of this pack. There are no means to adjust the harness to accommodate varying torso lengths. However, the G Pack is offered in three sizes (small, medium, and large) to fit torso sizes from 15.5 to 21.5 inches (39 to 55 cm). The shoulder straps are contour cut and fit very well. The harness is completed with waist belt and shoulder strap stabilizers and a sternum strap. The padded back panel only makes contact at the lumbar and shoulder blades creating channels in between that allow air movement between the pack and wearer.

 

Usable Features and Ease of Use – 2.5

 

The G Pack has an unusual pocket configuration that is both uniquely functional and cumbersome to use. Rather than having two side water bottle pockets and one large back pocket, as many lightweight packs do, the G Pack has one large pocket that covers both side panels and the back, named the “bucket pouch” by Gregory. It can accept lots of small gear, or take on enormous items, as needed. This pocket is secured along its top edge by three side-release buckles that connect the pocket to each side panel and to the top compression strap. These also act as the pack’s primary compression system. The deep side panel pockets are unreachable with the pack on. For that matter, none of the pockets are accessible while wearing this pack. What makes this pocket cumbersome to use is the top or center compression strap. A single strap compresses the top of the pack, underneath the top pocket, and also attaches and compresses the center panel of the back pocket. Since one webbing strap does it all, this arrangement necessitates the adjustment of both the top compression of the pack and back pocket at the same time, a task that requires removal of the top lid pocket. We would prefer the increased weight (a weight only measurable in grams) of an additional piece of nylon webbing that would allow independent adjustment of the top and pocket compression.

The top lid pocket is standard enough. It attaches cleanly with four adjustable side release buckles, one at each corner, and compresses the pack well. A #5 YKK weather resistant coil zipper closes this pocket. Although the top pocket can be removed, doing so leaves four long sections of nylon webbing dangling from the pack. Diehards, wanting to loose the top pocket permanently, can do so by cutting these nylon straps.

The main pack bag closes like a stuff sack, with a draw cord and cord lock. As mentioned previously, a single nylon strap with a side release buckle goes over the top of this opening (underneath the top pocket) for vertical compression. Gregory added an extra bit of reinforcement material where the draw cord enters the pack to protect the silnylon from ripping.

The G Pack further misses the mark by not providing a hydration system friendly pocket and tube port. It is difficult to stay hydrated while wearing this pack. This pack also lacks the ability to carry ice axes or long items as there are no tool loops or upper side panel attachment points. The pocket and compression strap configuration limits sleeping pad storage to the inside.

Load Volume Flexibility (Compression) – 3.0

With a total of eight compression straps, the G Pack excels at compressing loads. Oddly, all of these compression straps compress in a mostly vertical direction. The exceptions are the compression straps connecting the sides of the main large pocket to the upper side panels, which angle at an upward diagonal, towards the backpanel. Nevertheless, the G Pack compresses well enough. Smaller loads are easily swallowed within the pack. Larger loads are a little more problematic. The G Pack lacks a daisy chain and only the two front compression straps connected to the top pocket can be used to lash on extra gear.

Field Performance

Pack Load Carrying – 4.5

Gregory claims a carrying capacity of 30 pounds (14 kg), which was unequivocally confirmed in our testing of the G Pack. We tested the G Pack with loads as high as 40 pounds (18 kg) reducing down below 20 pounds (9 kg). At the heavier weights, the lighter hip belt and single stay were unable to completely transfer weight comfortably to the hips. The single, centered aluminum stay could not transfer this weight to the shoulder strap stabilizers’ upper attachment which caused some torso collapse. This required adjusting more weight onto the shoulder straps, which were not up for the task and quickly became uncomfortable. At, or around 30 pounds (14 kg), the G Pack’s frame and suspension was comfortable, with minimal frame collapse and sufficient padding for those loads. The single stay and framesheet are vertically supportive and able to transfer weight to the hips and provide enough pack flexibility for the hips and shoulders to twist independently of each other. For a pack designed to carry 30 pounds, the G Pack does so in comfort without unnecessary rigidity.

Durability – 2.5

Although the main body of the pack uses 30 denier, 1.3 oz/yd² (44 g/m²) silnylon “G fabric” to reduce weight, most high wear areas are covered by 210 denier double ripstop nylon. The 210 denier ripstop was used for the bottom, up the middle of the back pocket, and across the top of the top pocket. The nylon mesh used in the sides of the large back pocket protects the G fabric side panels. The silnylon is exposed in two narrow strips down the back pocket and quite extensively above that pocket.

We tested the G Pack down a narrow, trail-less canyon in northern Arizona which included numerous encounters with dense vegetation. In our testing, the 210 denier double ripstop held up well to conscientious use, but not at all to abuse. The silnylon was hidden well enough behind tougher fabric to resist most encounters with abrasion and snags, which generally occurred on the lower portion of the pack. The exposed silnylon on the back pocket was susceptible to wear, particularly when dropping the pack on the ground or leaning against brush. Care must also be taken when passing low overhanging branches so they do not find their way through the exposed G fabric on the upper portion of the pack. It was suitable to omit climbing attachment options on this pack, as its fabric will not tolerate encounters with abrasive surfaces.

Value – 2.5

At $149, the G Pack is priced on the low end compared to other lightweight internal frame packs. However, the exposed areas of G fabric greatly reduce its durability. It also lacks accessible pockets and options for hydration.

Recommendations for Improvement

The comfortable-to-carry Gregory G Pack could be optimized with improved pocket accessibility. In order to keep the current pocket configuration, we recommend adding two water bottle sized pockets, one on each lower side panel. Attaching them with side release buckles, such that they can be attached low and are removable allowing the bucket pocket to remain, might be the best option for this pack.

We would really like to see Gregory add an additional nylon webbing strap for the back pocket’s center adjustment strap, thus allowing separate adjustability for the back pocket and pack’s top compression. This would only add a nominal amount of weight, if any at all, as the current single strap is much longer than necessary.

More options for attaching gear externally would be an improvement that could extend the load volume carrying capacity. Even a single daisy chain running up the middle of the back pocket, with an ice axe loop at the bottom, would make a significant improvement in this regard. The benefits of these changes would outweigh the minimal weight increase. Although this is not a climbing pack, the additional attachment options would be suitable for attaching trekking poles or a jacket that does not fit inside the pack.