Articles (2020)

Overview

The Sierra Designs Hyperlight is the roomiest two-person lightweight tent we reviewed. It has more usable area than other tents considered to be spacious, like the MSR Hubba Hubba. The Hyperlight’s large asymmetrical floor plan, optic white tent walls, and mosquito netting create a huge, bright and pleasant living area – an antidote to tent-bound claustrophobia from long periods of rain or heavy bug pressure. (Tent pictured at right is under siege from formidable Maine mosquitoes in high summer.)

What’s Good

• Roomy – largest floor area of lightweight two-person tents reviewed
• Our highest rated large durable tent – reflects an excellent balance between weight, durability, weather performance and usable space
• High area to weight ratio for a tent with durable fabrics and materials
• Asymmetrical floor plan increases usable space over traditional rectangular tents
• “Jake’s corner,” a short third tent pole, is one of a number of low weight features to increase wind stability
• Durable floor hold ups well to field abuse

What’s Not So Good

• Lower area to weight ratio compared to the very lightest (but less durable) double wall tents
• Single door
• Long side of tent (body and rainfly) could use an extra tie out or two in high winds to reduce sidewall deflection
• Asymmetrical floor plan may not suit all tastes
• Included tent stakes are heavy

Specifications

Performance

The outstanding feature of the Sierra Designs Hyperlight tent is its large floor area. We found the asymmetrical floor plan to provide plenty of room for two sleepers while leaving enough extra room to store all our gear. The yellow fly and white optic tent canopy let lots of pleasant light in. The tent has a single oversized door and vestibule. There are numerous pockets to hold hard-to-keep-track-of items. Although there is no attic for the tent, we found hanging a line from the loops in the tent ceiling sufficient for our needs.

The Hyperlight has an exceptional area to weight ratio for a full-featured tent with a durable 70-denier floor and a strong 40-denier fly and body. Its area to weight ratio is comparable to some very light tents using silnylon floors, mesh tent bodies, and silnylon flies, like the Big Agnes Seedhouse SL2.

For a large and relatively light tent, the Hyperlight is strong enough to withstand substantial wind. When kayaking along Florida’s Gulf Coast we were surprised by a sudden overnight cold font. The winds shifted to blow straight off the gulf onto our exposed beach campsite, hitting the tent broadside. By the time we realized it, the winds were too high to allow re-pitching of the tent with the foot into the wind or to find a more sheltered spot. All we could do was guy the tent out as best we could and wait. The strong winds persisted and we were forced to wait for a day, as we couldn’t launch off the beach in the high surf. The Hyperlight survived 30 hours of constant 45 mph broadside winds with some higher gusts. Many lesser, non-mountaineering tents would have flattened. Our only gripe with the Hyperlight was that the windward sidewalls deflected in particularly strong side gusts.

The Hyperlight uses a number of innovative features to stabilize and strengthen the large tent without adding too much weight. These include a short third pole called “Jake’s corner” and a “Clip Loc” at the intersection of the two crossing poles. The Clip Loc creates a rigid non-slipping joint where the two main poles cross.

Pitching ease on the Hyperlight is about average. There are faster and more innovative pitching systems out there. In defense of the Hyperlight, its focus is on tent strength, where it has an advantage over many tents in its class. With its strength, high fabric walls and a minimum of mosquito netting, the Hyperlight could be pushed to a 3+ season tent.

The two main poles are in a standard crossing X pattern with clips attaching the tent body. The Hyperlight has a few more pitching tasks than a traditional two pole, rectangular X tent. There is wrapping the Clip Loc at the pole intersection, attaching the Jake’s corner, and the asymmetrical floor requires six stakes instead of the normal four for a rectangular tent. The tent comes with eight 6-millimeter diameter aluminum shepherd’s crook stakes. While the stakes work reasonably well, the aluminum can bend and they are heavy at 0.55 ounce each. The shepherd’s crook stakes are much easier to palm into the ground than the sharp-ended stakes provided by many tent manufacturers.

Attaching the fly is easy with snap buckles and color-coded webbing. The webbing is substantial with excellent tension adjusting buckles. There are two pole grommets on each body stakeout webbing to allow for stretch when the tent is wet.

The Hyperlight provides good rain protection with its high catenary cut, and well-tensioned bathtub floor. The high sidewall fabric provides good protection from rain blowing in under the fly. We had no problems staying dry in the tent. There are no vents on the tent fly, and limited amounts of mesh in the tent body. The Hyperlight depends on wind under the gap between fly and ground to ventilate the tent and reduce condensation. In use, we did get condensation on the inside of the fly on cool, humid and windless nights. Little if any of this condensation found its way into the tent proper. A peak vent in the fly would lessen condensation.

After extensive field testing in a variety of environments, the Hyperlight has shown no durability issues. We’ve used it on rough mountain ground with too many rocks and sharp sticks to clear, and in unforgiving rocky beaches with sharp shell fragments, coral pieces, and other floor damaging detritus. The floor is still intact. The tent also survived substantial wind and rain with aplomb.

At $269.95 the Hyperlight is very price competitive with the MSR Hubba Hubba ($299.95), the Sierra Designs Lightning ($249), the Big Agnes Seedhouse SL2 ($299) and other tents in its class. The Hyperlight’s advantage over many of these tents is substantially more room, an excellent area to weight ratio, and more durability compared to silnylon based tents like the Big Agnes Seedhouse. The Hyperlight provides good wind stability and storm protection. If you want a large tent and don’t mind it being a bit heavier than the smaller tents then it is a good value.

What’s Unique

My wife and I like the asymmetrical floor plan of the Sierra Designs Hyperlight tent. There is plenty of room for the two of us in the middle. The storage area remaining in the corner area of the tent is huge. In mosquito infested campsites we could bring all our gear into the tent and even spread out a bit without feeling cramped.

The Hyperlight has good wind stability without adding too much weight: the “Jake’s corner” does a good job of stiffening-up the 9.5 foot long side of the tent without the weight of a full sized pole. It also spreads out the terminal corner for more space. A “Clip Loc” (a fancy term for a multiple wrap of shock cord) binds the intersection of the main poles into a rigid non-slipping structure to improve the tent’s stability with minimal increase in weight.

The Hyperlight has a very high area to weight ratio for a durable double walled tent. It uses 70-denier fabric in the floor where it is most needed, combined with lighter 40-denier tent body and fly fabrics, an asymmetrical floor plan, and a number of lightweight solutions to increase tent stability and strength.

Recommendations for Improvement

• Two doors is fast becoming an industry standard for two-person tents. Fortunately, the Hyperlight’s single door is large and at the head of the tent so you don’t have to crawl over your tent partner to get out. But with a second door you’ll always have a lee exit even if the wind changes, or for campsites with access to only on side of the tent (assuming you want to keep the rear of tent pointing into the wind).
• The single vestibule may be small for two people. This applies only for storing wet and muddy gear. There is plenty of room in the tent for dry gear.
• High fabric walls (non-mesh) on tent body reduce ventilation and limit views when the rainfly is off. (It does however, provide warmth and additional splash and wind resistance for the lower edge of the rainfly.) A peak vent in the fly would vent moisture via convection and reduce condensation.
• A few extra guyline attachment points on the tent body and fly would help reduce wind deflection along the tent’s 9.5 foot sides (this is especially true if the wind shifts to hit the tent broadside). Attaching the tent body to the center of the fly on the longer sides would help with sidewall deflection as well.
• Window(s) or some other option to see out of the fly would be nice.
• Include lighter stakes with the tent

Introduction

The Evolution 2P is the flagship of Big Sky International’s now extensive line of lightweight shelters. Simply stated, it is the lightest, best designed, most user-friendly three-season two-person double-wall freestanding tent available. This review presents the facts behind that statement and makes recommendations to make the Evolution 2P even better.

What’s Good

• Lightest two-person double-wall freestanding shelter with two doors and two vestibules
• Fibraplex carbon fiber poles are strong and light, and withstand moderate winds (assuming good staking)
• Titanium stakes included
• Fast and easy setup
• Superb views and ventilation with the fly off
• Both vestibules offer space for a pack and boots without blocking entry
• Vestibules are easily accessed from outside or inside the tent
• Large zippered mesh entry doors
• Large mesh gear/clothing storage pockets
• Adequate length and headroom for taller people
• Good wind stability if you use four angled guylines

What’s Not So Good

• Inner mesh tent contacts the fly in some places, and some condensed water can drip inside the tent
• Only eight stakes and two guylines are included (12 stakes and four guylines are needed for a stable pitch in moderate winds)
• With carbon fiber poles, the tent deflects a lot in moderate winds, especially from the sides (aluminum poles are highly recommended if you expect strong winds or snow loads)

Specifications

Performance

The Big Sky International Evolution 2P is a three-season two-person double-wall freestanding tent with two vestibules and two doors. There are lots of other tents out there with the same feature set, like the MSR Hubba Hubba, Sierra Designs Hyperlight, REI Quarter Dome UL, and The North Face Vector 22. However, there’s one BIG difference: the Evolution 2P is a pound (or more) lighter than these tents. The Evolution 2P weighs 3 pounds 6.4 ounces (my measurement, which includes stakes, guylines, and stuff sacks). Put another way, the Evolution 2P at 0.63 ft²/oz with carbon fiber poles, has the most tent area for its weight among these tents.

As the name implies, the Evolution 2P has had some…evolution. Our SpotLite Review published in 2005 was based on Revision A. The current model is Revision C, and Revision D will be out in April 2006. With each revision, the design is tweaked and the tent becomes even more user-friendly.

Design

I will start this review with a photo gallery of the outside of the tent to get you familiar with its design.

Features and Ease of Use

Overall, the Evolution 2P “gets it right”:

• All tent components are lightweight – Fibraplex carbon fiber poles, titanium stakes, mesh inner tent, and silnylon floor, fly, and stuff sacks
• Fast, easy setup – no complex instructions, set it up in minutes
• Easy entry – large zippered side entry doors in the vestibules and inner tent
• Plenty of storage options – the vestibules are 9.5 square feet each, enough for a backpack and boots, and there are four large interior mesh pockets
• Plenty of room – while 32.7 square feet of floor space for two people isn’t huge, the steep tent walls, storage pockets, and vestibules add up to tons of usable space
• Convenience – two vestibules and doors plus plenty of pockets allow tent mates to remain good friends, and everything is within easy reach
• Fly only option – the tent can be pitched using only the fly, poles, and optional footprint, (total weight 2 pounds)

Ventilation

The mesh inner tent allows maximum airflow. There are two large vents at the tops of the vestibules, and the fly is raised off the ground enough to provide good high-low airflow. Most condensation forms on the inside of the fly, but the mesh inner tent can contact the fly in a few places to transfer water, sometimes dripping into the tent.

Wind Stability

The fly has four Velcro tabs to anchor it to the pole sleeves. This along with corner attachments, eight stakes, and two guylines are adequate for “normal” conditions. However, for stability in strong winds (and to protect your investment), I strongly recommend using four guylines at 45-degree angles to the corners. For a truly wind stable pitch, twelve stakes and four guylines are required.

With carbon fiber poles, don’t even think of using this tent without four guylines! Even with good staking, it still deflects a lot in strong winds because of the poles’ flexibility. A strong wind from the side will nearly flatten it. If you expect to use this tent in above average wind (more than 30 mph) or snow conditions, I strongly recommend getting the stiffer/stronger (and less expensive) aluminum poles.

For the best of both worlds, you might consider owning both pole sets: a carbon fiber pole set for less severe conditions, and an aluminum pole set to use when you expect snow and/or strong winds.

Storm Protection

The fly completely envelops the tent and has good overlap with the bathtub floor. The floor is silnylon, with a hydrostatic head pressure rating of 1800 mm, which means that water can pass through in places where you apply pressure (like sitting on the floor, or your hip contact area while sleeping). Therefore it’s important to pitch the tent in a well-drained area.

My wife and I weathered numerous showers, rainy nights, and even a light snow in the Evolution 2P and stayed dry and cozy. The silnylon fly stretches when damp or wet, so it’s important to keep the fly tensioned so it doesn’t contact the mesh inner tent.

Assessment

The ideal application for this tent is three-season camping with a spouse or close friend, or solo hiking for folks that like the comfort, security, wind resistance, bug protection, and privacy of a double wall tent. For two people, ease of use is hard to beat with the Evolution 2P. Each occupant has plenty of interior pocket storage for organization, and dual vestibules and doors go a long way towards keeping tent mates close friends. Vestibules are large enough for boots, a mid-sized backpack, and plenty of other gear. The fly is adjustable in several different positions on each vestibule side, allowing you to fine tune ventilation and views ranging from entirely open sides to fully sealed. Vents at the top of the vestibules vent moisture, and a clear vinyl window brings morning light into the shelter.

This tent is not bombproof by any means. While I would not call it fragile, the Evolution 2P does require special care. There are definite limits to the abrasion and puncture resistance of silnylon and no-see-um mesh. Setting it up on sharp rocks or stubs could puncture the floor, and rough edges or stubs could snag the mesh or fly. This is where heavier tents with more durable floors, like the MSR Hubba Hubba and Sierra Designs Hyperlight will have an advantage.

A final thought: if you get the Evolution 2P with carbon fiber poles, you are paying $85 more to save 4.6 ounces. Carbon fiber poles are subject to breakage at the connections, and require careful use. They are also more flexible, so the tent leans in response to wind gusts. Bottom line, the 7000-series Easton aluminum poles are bomber and cost a lot less, so give them some serious consideration. The 2P with aluminum poles is an excellent value at $260.

What’s Unique

The Evolution 2P is the lightest two-person double-wall freestanding shelter available with two doors and two vestibules. Besides being a lightweight champ, it is exceptionally well designed and user friendly.

Recommendations for Improvement

• Add guyline loops to each end of the fly and to each vestibule for extra wind anchorage.
• Offer a guyline kit for use with carbon fiber poles that includes enough guylines and stakes for good wind stability.
• Offer a heavy-duty version with a more durable floor, aluminum poles, and extra guylines and stakes.

Introduction

In a crowded field of lightweight one-person single wall tents, the Big Sky Revolution 1P’s distinction is that it is the lightest freestanding breathable fabric tent available. Notice the adjectives. There are lighter and roomier solo tents available, but they are not made of breathable fabric.

• The Mandatory Gear Puppy Pile tent at 25.1 ounces is the lightest freestanding solo tent (actually adventure racers like to cram the whole four member team into one tent!), has loads of floor area (36.7 square feet), but it is made of non-breathable silnylon and is a sauna with its minimal ventilation.
• The Tarptent Virga 2 weighs a couple ounces less, has 77% more floor area, is well ventilated, but is not free standing
• The Lightitude Award winning Six Moon Designs Lunar Solo provides 57% more floor area and weighs a scant 23 ounces, but it is also made of silnylon and is not freestanding
• The new Rainbow by Tarptent is neck and neck for the title – a prototype silnylon version weighs 32 ounces, but production versions are promised to weigh 24 ounces, and an Epic version of this free-standing tent is likely.

So, what are the notable features of the Big Sky Revolution 1P that might persuade you to choose it over the others? Read on.

What’s Good

• Lightest freestanding breathable fabric solo tent
• Fibraplex carbon fiber poles are very strong for their weight
• Fast setup with clips attached to external poles
• Epic fabric and vestibule vent provide good breathability in warm weather
• Vestibule offers space for a small pack and boots plus good access to entry door
• Vestibule is easily accessed from outside or inside the tent
• Large zippered mesh inside door
• Large mesh gear storage pockets
• Adequate length and headroom for taller people
• Good wind stability if you use four angled guylines

What’s Not So Good

• Zipper on vestibule easily snags on the storm flap, especially when zipping from inside
• High condensation at cool and cold temperatures
• Dark blue color makes it dark inside (but color will change to granite gray)

Specifications

Single Wall Tents and Condensation

Condensation or frost on the inside of a single wall tent is a fact of life and completely agrees with the laws of physics. For an in-depth explanation of condensation processes, read Mariah Walton’s article on Night Time Condensation on Tarp and Tent Fabrics.

Condensation occurs when the temperature of the tent fabric drops below the dew point of the surrounding air. For a breathable fabric tent, the process is as follows:

• As the air cools at night, the amount of water vapor it can hold decreases
• Because of nighttime infrared radiation, the tent walls typically cool below the air temperature at night, creating a cold surface
• Campers inside the tent generate lots of water vapor from exhalations
• At warmer temperatures (above about 50 F, as long as the outside air is above the dew point), the inside air will hold significantly more water vapor and moisture can be adequately exhausted via tent ventilation and passage through the tent fabric
• But at cool/cold air temperatures (a situation where the outside air is near or below the dew point), people’s activity inside the tent my provide enough energy to drive moisture through the tent fabric, but after the activity stops and the temperature drops further there is not enough energy (temperature/vapor pressure gradient) to drive moisture vapor through the fabric
• As warm/moist air reaches the cold tent wall, the dew point is exceeded in the air near the wall, and condensation results
• When the temperature is below freezing, the result is frost on the inside of the tent

The principle is similar to condensation or frost forming on the inside of your car window, or condensation on a glass of ice water.

Breathable fabric helps, but tent ventilation is the primary mechanism to exhaust moisture from a single wall tent, especially at low temperatures. A tent made of non-breathable fabric (silnylon) is totally dependent on ventilation to exhaust moisture, so serious condensation can occur when ventilation is inadequate and temperatures drop below the dew point. As explained above, at low temperatures, a breathable fabric tent performs about the same as a non-breathable fabric tent, i.e., they both have abundant condensation (depending on the amount of ventilation).

In the case of a double wall tent, the inner tent fabric is usually very porous, so moisture laden air is more likely to pass through rather than condense. If ventilation within the fly is good, the moisture will be whisked away, but if ventilation is restricted, condensation or frost is likely to occur on the inner surface of the tent fly.

Performance

The Big Sky Revolution 1P shelter is designed to be light. The shell is lightweight Epic water-resistant/breathable fabric by Nextec. The bathtub floor is silnylon. The entry wall is mesh. Provided stakes are titanium, and the tent is available with either Easton aluminum poles or Fibraplex carbon fiber poles. The complete package with carbon fiber poles weighs 36.3 ounces (my measurement) and provides 17.5 square feet of floor area plus an entry vestibule with 9 square feet.

Setup is quick and easy. The Revolution 1P has two external poles that slip into grommets at the four corners of the tent to create an asymmetrical “X” frame. The tent body attaches to the frame with clips and then is staked at the four corners plus two loops on the vestibule.

Although the Revolution 1P’s 17.5 square feet of floor area is a bit small compared to other solo tents, it has a very large zippered mesh entry door that ties off to one side. This functionally adds the vestibule’s 9 square feet to the tent’s usable space, making the tent seem a lot roomier. The doors in both the vestibule and mesh wall are tall and wide for easy entry and exit. Inside the tent all of the space is usable because of the tent’s steep walls, 84 inches of length, and 39 inches of headroom. I left the mesh door open most of the time, which increased interior roominess and allowed easy access to items in the vestibule.

One annoyance I encountered was the vestibule zipper’s tendency to snag on the storm flap. It happened most often when I was unzipping from the inside, and caused consternation a couple of times when it snagged in the middle of the night when I was trying to get outside for bladder relief.

The tent I reviewed was a dark blue color, which made it pretty dark inside. However the production tents by the time you read this review will be a light gray and much brighter inside. The newer fabric will be slightly heavier (adding about 1 ounce to tent weight), but it is about 25% stronger.

The tent has an eye-shaped window at the foot end, which provides a fair amount of light. Interior accompaniments include a 20-inch by 6-inch mesh stow pocket at the head end and a large triangular “clothes hamper” in a corner at the foot end. The ceiling has four loops for a clothes line or suspending a tent light.

For a wind-stable pitch (which I consider a necessity to protect your investment), the tent should be tautly anchored with six perimeter stakes plus four guylines at 45 degree angles to the corners. Eight 6-inch titanium stakes and two guylines are provided with the tent, but 10 stakes and four guylines are required for a secure pitch. With proper staking, I found the Revolution 1P with carbon fiber poles to be surprisingly stable in a 30 mph wind, and had no problems with the clip attachments. If you anticipate frequent exposure to strong winds, I advise getting the stiffer Easton aluminum poles for more wind stability.

I added the section on single wall tent condensation to this review for a reason. During my testing, mostly in cool and cold weather, I found that the Revolution 1P accumulates a lot of condensation or frost inside. The condensation was enough to form larger droplets and run down the sides of the tent (see photos). Unless there was a good nighttime breeze, I found the condensation hard to avoid at cool and cold temperatures (as explained in the section on condensation).

A big contributor to the condensation problem is the Revolution’s ineffective high-low ventilation. There is a large vent at the top of the vestibule, but the only provision for ground-level air entry is a small gap at the bottom of the vestibule. The entire ventilation system is on the vestibule, and the bottom of the vestibule stakes nearly to the ground, which limits air entry. There is no provision for ventilation in the main tent, other than fabric breathability.

The condensation issue is not unique to the Revolution 1P; when I slept in a borrowed Black Diamond Lighthouse tent (also made of Epic fabric) on a 12 °F night I had abundant frost on the inside tent walls – the same situation as the Revolution 1P. So, my point is that condensation and frost on inside tent walls is a fact of life in single wall tents (including breathable fabric tents at cool/cold temperatures), and the only factors that seem to make much difference are abundant tent ventilation and a good breeze.

In warmer weather, the Epic-shelled Revolution 1P worked with aplomb. On several nights with temperatures in the 50’s and 60’s I had no inside condensation at all. For three-season use in predominantly warm weather conditions, the Revolution 1P will provide very user-friendly shelter with a minimum of condensation issues. When you do get condensation in extended rainy weather, a good solution is to wipe down the inside tent walls with a towel.

I weathered both rain and snow storms in the 1P and found it to be plenty storm worthy. Although the Epic fabric is only water-repellent, it sheds rain very well because of the 1P’s steep walls and tautness. I found that it would eventually wet through in prolonged rain, causing weeping on the inside, which exacerbated the condensation problem. Snow typically stuck to the outside of the tent and required slapping the tent walls to get it to slide off. Although the Revolution 1P will handle a light snow, I don’t recommend it for snow camping. The Big Sky Evolution 1P or 1P EX with aluminum poles would be a better choice. Their double wall construction with silnylon fly will shed snow much better than the Epic fabric single wall Revolution tent.

Overall, I found the Revolution 1P to be very well designed, very user friendly, and very storm worthy and wind stable. It’s also a great value compared to the competition.

What’s Unique

The Big Sky Revolution 1P is the lightest freestanding breathable fabric one-person tent on the market, and that includes a vestibule.

Recommendations for Improvement

The Revolution 1P is well designed, is very user friendly, and provides most of the features a lightweight backpacker would want. Some suggestions:

• The single vent on the vestibule is not enough to lessen condensation in cool/cold/wet conditions. Some serious high/low vents are needed to increase tent ventilation and exhaust moisture
• Redesign the zipper and storm flap on the vestibule door so it can be easily zipped and unzipped from the inside

Introduction

Mountainsmith’s popular MountainLight series is gone and is being replaced with a new TrekLight series that so far consists of the AT 55 and PCT 45/CDT 45. The new packs depart from the familiar beige Dimension Polyant fabric, and are frankly “softer” and more user-friendly. The AT 55 essentially replaces the popular Auspex, but the new pack is so different that they can hardly be compared. A closer comparison is with the new 2006 Osprey Aether 60 which we recently reviewed. How does the new TrekLight AT 55 stack up as Mountainsmith’s new frontrunner lightweight pack, and how does it compare with Osprey’s Aether 60? Read on.

What’s Good

• X frame is flexible and effectively transfers weight
• Suspension system easily adjusts for a perfect fit
• Firm, comfortable shoulder harness and hipbelt
• Top lid converts to a day pack
• Eight outside pockets provide plenty of convenient storage
• Water-resistant zippers operate smoothly
• Zippered map pocket under top lid
• Zippered access to main compartment
• Lightweight yet durable fabrics

What’s Not So Good

• Heavy by lightweight standards.
• Zipper on the main compartment opens from the top (it would be more convenient if it opened from the bottom)
• Inside PU coating on side stretch-woven pockets resists when sliding in gear or water bottles
• Straps and buckles on the top pocket make conversion to a day pack cumbersome
• Hipbelt pockets are too small
• At 4 lbs 3.3 ounces, the AT 55 is heavier than we would like

Specifications

Performance

The rather low, 3356 cubic inch (55 L), volume specification for the new Mountainsmith TrekLight AT 55 is deceiving. In reality it has about the same capacity as the old MountainLight Auspex/Chimera packs and the new 2006 Osprey Aether 60. The weights of these packs are equivalent within an ounce or two, so the real considerations are features, load carrying ability, and comfort. I will start with a full description of the AT 55.

While the previous Mountainsmith Auspex was rather utilitarian with its dominant (stiff and very durable) Dimension Polyant fabric and minimal features, the new TrekLight AT 55 is constructed of a variety of fabrics and is loaded with features. The pack body is 210 denier Cordura nylon with a white PU coating on the inside for better visibility, while the bottom is heavier 420 denier Cordura. Stress points are reinforced with Hypalon. Overall, the AT 55 pack fabrics are an excellent balance of lightweight and durability.

The outside bungee attachment system on the Auspex is replaced by real pockets, lots of them. The pack has a total of eight outside pockets: two stretch-woven side pockets, two stretch-woven front pockets, two hipbelt pockets, and a top lid with a zippered map pocket on the underside. The stretch-woven pockets have ample bellowing and gusseting so they have good capacity even when the pack is stuffed full. I am thankful for the hipbelt pockets, but they are small and will hold only the smallest items.

A nice feature on the TrekLight AT 55 is zippered outside access to the main compartment. A 14.5-inch water-resistant zipper on the right side of the frontpanel extends to about the middle of the pack. However, the zipper opens from the top, which is under the top lid. It would be more convenient for it to open from the bottom.

Another nice feature is a removable top lid that converts to a fanny pack or day pack. The lid quickly detaches from the backpanel with two side-release buckles. With the straps extended, the lid can be worn as a fanny pack or as a shoulder pack. The straps are a little too short for use as a shoulder pack and it’s a struggle to get it on and off. As a fanny pack it would work much better if one buckle was reversed where it attaches to the backpanel, which would make opposite buckles mate. As it is, only diagonal buckles mate.

The TrekLight AT 55’s frame is very different from the former Auspex. The Auspex had two vertical sleeved stays that could be removed and bent to fit the user. The AT 55 also has two flat stays, but they are arranged in an X pattern, with the ends secured in Hypalon sleeves. This arrangement discourages the user from removing the stays and bending them. I found the shape satisfactory as is, and did not feel the need to adjust it.

The AT 55 is available in regular torso and large torso versions (equivalent to size medium or large). To dial in the fit, the pack torso length is adjusted by raising or lowering the hipbelt on a Velcro pad, in combination with adjusting the shoulder strap length.

I found the AT 55’s suspension system to be first class. The backpanel is thermo-molded firm EVA foam with extra padding in the lumbar region. The wide, thick shoulder straps and hipbelt are also firm EVA foam to increase their capability to carry heavy loads. The hipbelt is further reinforced with a thin external polyethylene sheet to increase stiffness and resist distortion.

On the trail, I found the AT 55 to be very competent. It easily carried 25 to 30 pound loads of lightweight gear with comfort. To see what the AT 55 would do, I loaded the pack with increasingly heavy loads up to 45 pounds, and found that its frame and suspension could handle anything that I could stuff in the pack. The limiting factor is how much weight you can carry without your knees buckling. For me (6 feet, 170 pounds), I found the AT 55 comfortable to carry all day with up to 35 pounds. The pack was capable of transferring all of the weight to my hips, and I tended to carry it without the sternum strap attached.

Assessment

Overall, the TrekLight AT 55 is a well-designed lightweight internal frame backpack capable of carrying a sizeable load with comfort, and is very user-friendly. It quickly became my favorite medium volume internal frame pack. This lightweight pack is loaded with features! I really like the numerous outside pockets that provide plenty of places to organize my gear and make items needed on the trail readily available. Also it readily handles a bear canister; a Bearikade Weekender (9 inches wide x 10.5 inches high) easily slipped in and turned to horizontal at the bottom of the pack.

How does the Mountainsmith TrekLight AT 55 compare with the 2006 Osprey Aether 60? I found the AT 55 to be more user-friendly with more outside storage space, while the Aether 60’s stretch-woven pockets were tight and would not hold very much. On the other hand, the Aether 60’s peripheral frame rods and load lifters allowed the pack to pull in closer to my back and maintain a closer center of gravity. Bottom line, they are both very capable packs, and each has pros and cons, so I recommend trying both before making a decision.

Unfortunately, the AT 55 breaks the 4 pound limit we normally place on packs this size, as does the new Osprey Aether 60. I expect both packs to be very popular, but speaking on behalf of lightweight backpackers, I would like to see pack upgrades without a significant weight increase. Although I really like the improved suspension and features of these packs, I would like the changes to be weight neutral.

What’s Unique

The new TrekLight AT 55 sets a new standard for a medium volume lightweight (not ultralight) internal frame backpack. Its design and materials are cutting edge, it’s very user-friendly, load capable, and fits very well. It can easily become a good friend on a long trail, like the AT.

Recommendations for Improvement

Of course, we’d like to see it be lighter weight. Other than that, specific recommendations for improvements are:

• Reverse the gender on one of the buckles of the top lid where it attaches to the backpanel. This will provide buckle ends that mate for easier use as a fanny pack
• Reverse the direction on the zipper providing access to the main compartment, so that it opens from the bottom rather than the top
• Eliminate the PU coating on the side stretch-woven pockets to save a little weight and allow items to slide in easier
• Increase the size of the hipbelt pockets
• Reduce weight by half a pound

Introduction

The MontBell U.L. Alpine Down Hugger Thermal Sheet is designed to fit inside another sleeping bag to use as a winter liner, but serves equally well as a summer stand-alone bag in warmer weather. I like this simple bag’s features, baffled down construction and the exceptionally durable-for-the-weight ballistic nylon fabric. My only complaints are a slightly trim fit and that the features add weight. You’ll have to decide if the features are worth the extra weight.

What’s good

• Baffled construction eliminates cold spots
• Full length, two way zipper and drawcord neck edge provide ample venting
• Full length zipper creates a handy foot pocket for hammock use
• Reversible design allows it to be a right or left zip to correspond to the outer bag’s zipper
• Fabric is highly durable for its weight

What’s not so good

• Lack of hood requires a skull cap or balaclava when used as a stand alone bag
• Slightly heavy for the amount of insulation it provides
• Girth is fairly snug in the chest

Specifications

Performance

The MontBell U.L. Alpine Down Hugger Thermal Sheet is a hoodless, mummy style sleeping bag liner. I found it equally usable as a warm weather stand-alone bag. Compared to other liners, this bag is well outfitted with a full length zipper, baffled down construction, and drawcord neck line.

MontBell uses 725 fill-power down (1 ounce of which will fill a volume of 725 cubic inches). Down is a great material for use as a liner bag. In cold weather, condensation will tend to collect on the inside of the outer most layer of fabric where vaporized moisture hits colder temperatures. When using a synthetic outer bag with the down MontBell Thermal Sheet as a liner, moisture will tend to condense on the outside of the synthetic bag with little reduction in loft of the down liner. When used alone in warmer temperatures, condensation is less of a problem.

The MontBell Thermal Sheet can also be used as a top bag either on the ground or in a hammock. Place the zipper on the bottom, with the foot zipped. The neck drawstring remains adjustable thanks to a Velcro closure at the neck. Using the Thermal Sheet as a top bag allows you to wear insulating layers, such as a synthetic jacket, without compressing the loft of those layers.

The Thermal Sheet is designed with uniform loft. I measured the loft in six places across the bag. The MontBell Thermal Sheet has 3 inches of double layer loft, or 1.5 inches of single layer loft. MontBell does not offer a temperature rating for their Thermal Sheet but the amount of loft compares to other bags rated for 50 °F to 60 °F temperatures.

The U.L. Down Thermal Sheet uses baffled construction. Down feathers will shift unless chambers are created to contain the down into confined spaces. Many bags this thin use sewn through construction, where pockets of down are separated by sewing through the bag. Sewn through baffles use less material and are therefore lighter, but heat is lost through the seams creating cold spots. The box construction baffles in the MontBell Thermal Sheet are only 0.5 inch high, preventing direct heat loss, but still reasonably light. With 1.5 inches of single layer loft, the baffle height suggests this bag is overstuffed, a condition that will prevent down from shifting towards the sides of the Thermal Sheet.

The full length YKK #3 non-separating double slider zipper on the Thermal Sheet allows significant venting options. The bag can be vented from the top down, or the bottom up using the lower slider. MontBell’s logo label would suggest the zipper is on the right side. However, the hoodless, symmetrical shape of this bag allows it to be flipped over, placing the zipper on the left, and consequently the MontBell label on the ground. This allows the Thermal Sheet to be used within either a right-zip or left-zip sleeping bag. A drawcord along the neck edge adjusts for ventilation or draft prevention at the neck and shoulders. Lacking a hood, the Thermal Sheet will prompt the use of a skull cap or balaclava in cooler weather.

With inside girth measurements of 60″/45″/38″, the MontBell Thermal Sheet is sized fairly typically for an ultralight sleeping bag. As such, using the Thermal Sheet as a liner within another ultralight sleeping bag will likely cause some loft compression in either the outer bag or liner. I gained very little warmth when using the Thermal Sheet as a liner inside a Marmot Hydrogen. The similar snug fit of these two bags kept the MontBell liner from lofting fully. When I used the Thermal Sheet with a top bag (homemade, down with 2.5″ of loft), I had much better results, lowering the top bag’s temperature rating by 10 °F to 15 °F. Other sleeping bags with an accommodating interior volume should see similar results.

I found the fit to be tight in the chest while moving my arms from the closure cordlock to my sides. This condition only presented itself when closing and opening the neck closure and did not affect comfort while sleeping. For reference, I am 5’7″ tall and weigh 155 pounds. For some, the fit may feel confining.

The Ballistic Airlight fabrics used in the construction of the MontBell U.L. Down Thermal Sheet have a high strength to weight ratio. Most of us associate Ballistic nylons with thick, heavy bullet stopping fabrics much more akin to war zones than to ultralight backpacking. It is not the weight of fabric, but the manufacturing process that gives Ballistic nylons their unique characteristics. The nylon fibers are heated and stretched, which aligns the nylon molecules in each fiber. Ballistic nylons are one-and-a-half times more abrasion resistant and have three times more tear strength than heavier nylons (according to MontBell). The fabric weighs 0.9 oz/yd². MontBell Ballistic Airlight uses hollow core fibers, which are flattened such that they overlay one another like shingles. The resulting fabric is very thin, down proof, and more durable than similar weight fabrics of conventional construction.

Missing from this review (and for all sleeping bag reviews published here, for that matter) will be an assessment of whether or not the sleeping bag performs adequately at temperatures near its manufacturer-reported temperature rating. Click here for the complete Backpacking Light Position Statement on Sleeping Bag Temperature Ratings.

What’s Unique

Baffled construction is rare in a bag this thin and eliminated cold spots. We also liked the use of ballistic nylons to create a strong, down-proof fabric at a respectable weight.

Recommendations for Improvement

Many will enjoy the venting opportunities gained from the full length zipper of the U.L. Alpine Down Hugger Thermal Sheet. Others will prefer a lighter weight. My recommendation is to reduce the zipper to a three-quarter length to shave weight.

Lighter materials could be used in the neck drawcord and cord lock, again to shed some weight.

I would prefer a tad more girth in the chest, though not in the shoulder. The shoulder girth should continue a couple of feet down the bag before tapering to the foot girth.

I liked the baffled construction despite the additional weight it adds. However, I do wonder how well this bag would perform with baffled construction only over the chest and feet, with sewn-through construction over the legs.

Introduction

The Big Agnes Lost Dog 50 is a synthetic fill sleeping bag that compresses into a tiny package. It is a top bag with insulation only above the sleeper, relying on a sleeping pad to provide insulation underneath. It is the lightest in the Big Agnes range of top bags at 21.2 ounces. The Lost Dog 50 has 0.4 inches of loft and is rated to 50 degrees F. Not a lot of loft for the weight, but it does have some advantages over ultralight sleeping bags.

What’s Good

• Light weight
• Compacts remarkably small for a synthetic bag (5 inch diameter x 10 inches long)
• Good price
• Seals to a rectangular sleeping pad without gaps at the sides
• Generously sized – plenty of room to move about
• Large enough to use as an overbag

What’s Not So Good

• Only 0.4 inch of loft
• Only 24% of the total bag weight is insulation
• Poor seal around the neck

Specifications

Performance

The Lost Dog 50 is a lightweight summer top bag. It has about the thinnest sleeping bag insulation available; 0.4-inch thick Primaloft Sport. This leads to the odd situation of only 5 ounces of insulation in a bag that weighs a total of 20 ounces. There are other synthetic fill sleeping bags that weigh the same and have more loft on top, and down sleeping bags that weigh the same with five times the top loft. However, in common with other Big Agnes bags, especially with the Classic Series, the Lost Dog 50 has much more room and is constructed of more durable materials than its ultralight competitors. The generous rectangular shape of the Lost Dog 50 provides ample room and comfort even for larger users. It has a full-length zipper, which adds to the usability – and also to the weight.

As a light summer bag the Lost Dog 50 performs satisfactorily but with one annoying problem. Sealing the gap between your neck and the sleeping pad is often difficult in hoodless top bags and the Lost Dog 50 also struggles here. If the drawcord is pulled tight it strangles your neck and doesn’t seal, if it is left loose the gap remains and the drawcord becomes redundant. (A less stiff sleeping pad reduces this effect.) When the temperature dropped a bit and I needed the warmth, the inability to cinch the neck up became a frustration – every time I moved I could feel the warm air pumping out of the bag. For anything but the warmest nights, I needed to wear all the insulated clothes I was carrying to stay warm inside the bag.

While the Lost Dog 50 is large enough to use as an overbag to boost the rating of another bag, the small amount of additional insulation makes it barely worth carrying the extra weight and I found myself looking for something with a bit more loft when I needed additional insulation.

Missing from this review (and for all sleeping bag reviews published here, for that matter) will be an assessment of whether or not the sleeping bag performs adequately at temperatures near its manufacturer-reported temperature rating. Click here for the complete Backpacking Light Position Statement on Sleeping Bag Temperature Ratings.

What’s Unique

The Big Agnes Lost Dog 50 is a synthetic top bag with much more girth and a more durable build, but less loft per weight than other down and synthetic summer bags.

Recommendations for Improvement

Doubling the thickness of the Primaloft insulation would only add 25 percent more weight to the Lost Dog 50 and would make it useful in a much wider range of temperatures. Also, a means of sealing around the neck (such as a draft collar attached to the bag bottom) would greatly improve the performance.

Introduction

A compact, top-loading, internal frame backpack, the Gregory G Pack incorporates lightweight materials and numerous features while hitting the stores at a competitive price. The G Pack elbows its way into a very crowded market segment where it might get lost in the mob if it weren’t for its effective load control and comfort – characteristics often missing in this group.

What’s Good

• Frame and suspension are effective and comfortable without stays
• Compression scheme manages diminishing loads
• Six external pockets, four accessible while wearing the pack
• Floating, removable top pocket
• Light and effective axe/trekking pole carriers
• Three sizes to fit more hikers

What’s Not So Good

• Considering the reduced-weight fabrics, it should weigh 8 ounces less
• Won’t accommodate most bear canisters
• Lower compression straps interfere with side pockets
• Too-short sternum strap also lacks an elastic damper
• Dark fabrics make it hard to see pack contents
• Fabric top-pocket zipper wicks water inside
• Test pack suffered seam failures

Specifications

Performance

The top-loading G Pack – 2700 cubic inches (48 L) in size medium – is part of Gregory’s Anti-Gravity series (large and small G Packs are also available). It sports an interior hydration reservoir pocket, one hose port, a removable lid pocket, two mesh side pockets, a mesh center front pocket with daisy chain, two mesh hipbelt pockets and an HDPE “Exo-Frame.” The chimney-style backpanel separates two breathable backpads and a lumbar pad to create an air channel. This review evaluates the G Pack’s ability to carry the recommended load, its packing flexibility, and life with it in the field.

Capacity and Loading Schemes

The G Pack is smaller than the average short-haul, three-season backpack but certainly adequate for weekends and a bit longer. While the G Pack fills quickly, it manages to hold my typical solo kit and up to about four days of food. Obviously, more compact gear ekes out more days, especially the sleeping bag, shelter, and carried clothing. A three-season synthetic bag for example, gobbles up a big chunk of the pack’s interior while a 2-pound or smaller down bag is a lot less greedy. Copious external pockets actually make the G Pack a lot more spacious than the volume specification suggests.

Sample Gear List

• Shelter: GoLite Hex 2 and groundcloth
• Sleeping Bag: Western Mountaineering Ultralight
• Sleeping Pad: Therm-a-Rest Prolite 4 Short
• Kitchen: Primus Ti Alpine stove, 220 g cartridge, MSR Ti kettle, MSR Ti mug, etc.
• Food, hangsack, and cord
• Water and Treatment: 1-liter AquaStar and bottle in one side pocket, 750 milliliter bottle in the other, 3-quart Nalgene canteen (carried empty)
• Clothing: Typical three-season kit
• Other Necessities: Toiletries, first aid kit, glasses, headlamp, map & compass, etc
• Extras: Camera (carried outside), film, GPS

The top-loading G Pack requires no unusual packing tricks; it responds well to the typical light, medium, heavy, medium progression from bottom to top. Excess clothing, along with rain and wind gear can go in the front pocket (when it’s not being used for wet gear) and the sleeping pad gets strapped either to the daisy chain (which is stabilized from above by a strap) or crosswise, beneath the top pocket. I use the inner hydration pocket when day hiking, but not for overnights because I usually need the interior space. The side pockets hold as much as a liter of water each or a host of small gear and snacks. Angled elasticized pocket tops ease access while wearing the pack, but the lower compression straps run diagonally across them and limit access when cinched tight. Two mesh pockets adorning the hipbelt wings host snacks, sunblock, lip balm, a small camera and the like. These are larger than typical belt pockets, covering each belt wing entirely.

No fewer than five straps anchor the floating, removable top pocket, helping to keep it centered. The pocket has a single zipped compartment with a key-keeper inside. Two ice axe loops and corresponding toggled elastic straps on the main packbag work well for carrying trekking poles, and are acceptable for heavier ice axes. They can handle a light monopod but not a hefty tripod.

With considerable wrestling, a Bearikade Weekender (9 inches wide x 10.5 inches high) fits vertically but it leaves little useful space once there. This probably isn’t a pack for touring in aggressive bear country.

Fit

The tested medium G Pack is specified to fit 17.5 to19.5-inch torsos. My torso measures 19.5 inches using Gregory’s fit kit, putting me on the cusp betwixt medium and large. After trying both sizes, I felt the medium fit me somewhat better in length and girth, although the shorter pack limited load lifter strap effectiveness. Because the pack has no back length adjustment, fitting is important before purchase. In sum, while the test pack fit me very well I urge anyone on the long end of the fit range to test a loaded one before purchase.

Once I’ve hoisted the G Pack and sequentially adjusted the various straps (waist belt, shoulder straps, sternum strap, top load control straps), it molds nicely to my hips and back. The Wraptor Stabilizer scheme integrates bottom load control with the shoulder straps, eliminating more-typical hipbelt load control straps. Looking at this system it’s not clear to me why it works, but it does. The semi-rigid Exo-Frame backpanel dispenses with a stay through molded U-section channels and doesn’t sag or collapse under load. Compared to the original G Pack, the new version has an impressive improvement in comfort and load control.

In Use

I can be a lazy packer and the G Pack is pretty forgiving. If I’m not careful loading the main compartment, the pockets can swallow an amazing amount of overage. So long as the front pocket isn’t loaded down with heavy items, its use doesn’t seem to affect load balance or control.

Keeping within Gregory’s suggested maximum 25-pound load limit, I found the G Pack effectively maintains control and comfort. Approaching 30 pounds, the pack sags and pulls away from my back, so the maker’s recommendation is right-on.

On terrain both level and steep the G Pack performs very well, providing excellent balance and load control and not interfering with pole use. I didn’t experience any sore spots, and adjusting the shoulder straps during the day helped reduce fatigue. The sternum strap is too short and lacks elastic damping. I got so tired of it I swapped in the elastic one from the original G Pack, something Gregory ought to do too.

Partial loads are well controlled via the load compressor straps (absent on the original model), the bottom load control straps do interfere with side pocket access though. The several top pocket straps help keep it centered as pack volume drops.

Wear and Tear

My technical travel with the G Pack occurred mostly while cross-country snowshoeing, offering plenty of bushwhacking, face-plants and general backcountry mishaps. No matter, the pack’s condition is fine with only minor fabric abrasion and padding distortion. The various light and heavier weight fabrics are strategically well placed and no snags appeared in the mesh. However, a seam unraveling in two places atop the packbag indicated sewing or thread defects. Although not in critical spots, their presence raises the question of whether there will be more seam failures (key stitching is bias-taped).

Tracking the Changes

Comparison with the original G Pack shows considerable evolution. Capacity is down, weight is slightly up and new features abound. The biggest changes are to the suspension, which now includes Gregory’s Wraptor Stabilizer system and Gullwing hipbelt.

The original’s flat thermoplastic framesheet with oval-section aluminum stay is gone, replaced with a fairly complex Exo-Frame framesheet. The new framesheet, no longer removable, has stiffening channels molded into it where stays might once have resided.

The original’s huge wrap-around bucket pocket has been divided into three pockets (side and center), a more useful arrangement, and the top pocket is better controlled by an additional anchor strap.

There’s the welcome addition of a drinking hose port and the odd replacement of the waterproof top pocket zipper with a plain one that wicks water. The sternum strap lost its elastic damper. G 30 fabric has been replaced by stronger, heavier G 70 cloth and last but definitely not least, are four new compression straps not present on the original (the first G Pack had poor load control when less than full).

The differences in load control and comfort are dramatic, with the new pack better in every way. The only potential downside is the lower capacity, but more capacity is available by going to Gregory’s Z Pack.

Assessment

Our sample medium pack weighs 47.6 ounces, 3.6 more than specified (+7.7%), and has a suggested (and realistic) 25-pound load limit (22 pounds, net). The G Pack is suitable for lightweight hikers who prefer a frame and who keep their load volumes small. It also makes a capacious day pack that’s especially useful in winter, although it has no specific provision for carrying snowshoes or skis.

The G Pack is a comfortable and compact backpack for weekend and somewhat longer trips. It’s not especially wide and keeps mass close to the body, which helps load control and maneuverability. The angled pack bottom makes steep downhill travel safer at the cost of reduced pack volume. A host of external pockets provide quick-access versatility and overload capacity.

What’s Unique

Gregory’s Wraptor Stabilizer system and Exo-Frame framesheet provide comfort and load control while eschewing metal stays or perimeter frames.

Recommendations for Improvement

• Cut the weight by half a pound and keep its comfort and feature set
• Lengthen the sternum strap and add an elastic damper
• Use a lighter color fabric to improve interior visibility
• Add a shoulder strap drinking hose clip
• Use a water-repellent zipper on the top pocket
• Mind the stitching

Introduction

With their 2006 introductions, Osprey will have more pack models than brands of cereal in your grocery store. The new Stratos line alone has five models. I tested the Stratos 34 general use daypack/overnight backpack – the largest of the Stratos line, and found a lot of nice features. The Stratos 34 is very similar to the popular Osprey Atmos 35, which was introduced in 2004. In this review I take a hard look at the Stratos and compare it to the Atmos 35. My pick of the two my surprise you.

Photo: The incredible balanced rock in the photo is for real, and can be found in the Red Canyon Recreation Area outside of Bryce Canyon National Park in Utah.

What’s Good

• Panel loading
• Excellent fit
• Four outside pockets plus hipbelt pockets provide lots of convenient storage
• Internal hydration sleeve plus additional water storage in backpanel cavity
• Well ventilated backpanel
• Straightjacket compression system
• Very comfortable suspension system

What’s Not So Good

• No hydration tube ports on main compartment
• No hydration bladder hanger in mesh backpanel cavity
• Mesh hipbelt pockets allow contents to get wet
• At 2 lb 13.8 oz., the Stratos 34 is not lightweight

Specifications

Performance

Building on the success of their lightweight Atmos pack line, with its innovative AirSpeed frame and mesh backpanel, Osprey is launching its Stratos line of general use daypacks with AirCore frame and mesh backpanel. The Stratos 34 is the largest of the Stratos line. It is a panel loader similar in size and features to the popular Atmos 35 (I will address the similarities and differences later in this review).

The AirCore frame and tensioned backpanel borrow from the AirSpeed design found on the Atmos packs. It consists of two fiberglass struts that anchor into top and bottom Delrin Acetal (high-strength plastic) wings. The assembly fits tightly into a mesh pocket and anchors to a center stabilization disk attached to the main packbag. The result is a concave frame and tensioned mesh backpanel with a cavity behind it.

The AirCore design with its tensioned mesh backpanel is form-fitting and allows full air circulation. It molded to my back like a water bed. While other packs use spacer mesh or other porous fabrics to increase ventilation between the pack and your back, the tensioned mesh backpanel virtually eliminates the wet-shirt-behind-the-backpack issue. Needless to say, this design is a winner, especially in desert environments.

The Stratos 34 suspension system consists of sewn-in spacer mesh contoured shoulder straps and hipbelt. The hipbelt is fairly thin (about 1/4-inch) and soft, but wide to distribute weight. The front buckle uses Osprey ErgoPull straps, which employ a pulley design to apply pressure evenly.

The mesh backpanel has a zippered access and hydration tube port at the top, so the cavity can be used to hold a water reservoir or a Platypus flask. My sample pack did not have a clip at the top to suspend a reservoir. Inside the main compartment there is a hydration sleeve big enough to hold a 3-liter water bladder. The specifications say that this pack has dual side hydration ports, but my sample pack did not have them. Rather, there was a slit connecting to the backpanel cavity and its one top/center hydration port.

When you add in the capability of the side pockets to carry water bottles, this pack has copious water-carrying capacity – as much as 10 liters – making it especially suitable for desert hikers or adventure racers. I personally liked to put my hydration bladder in the backpanel cavity because it saved room in the main compartment and my back kept the water warm in the wintertime.

The outside of the pack is adorned with useful features. There are three large stretch woven pockets on the front and sides that will hold water bottles or an assortment of stuffable items. The side pockets are ample, big enough to hold two slender 1-quart bottles in each one, and you can reach a water bottle with the pack on. A roomy mesh-lined pocket with water resistant zipper at the top of the frontpanel provides secure storage, and has a key clip inside. It’s big enough to hold your lunch. In the same location there are two elastic accessory cords to help attach items to the front of the pack. The mesh hipbelt pockets are bellowed and run the full length of the hipbelt wings; the zippered opening is 8 inches long. The pockets are most useful for smaller and more stuffable items. A compact digital camera will fit, but the mesh pocket does not provide much protection from dirt or weather.

As I mentioned, the Stratos 34 is a panel loader. The front panel zipper is about ¾-height with a double slider. All of the zippers on the pack have Osprey’s new finger loop zipper pulls that are really slick. The frontpanel has Osprey’s Straightjacket compression system, which provides two straps to attach gear to the front of the pack, or extend over the pack to clip to a buckle on the opposite side to compress the entire pack for smaller loads. Each side of the pack has a lower ski loop and upper strap to attach skis or other gear.

With its innovative frame and full-featured suspension system, the Stratos 34 is capable of carrying weighty and bulky loads, and attaching various pieces of gear (skis, snowshoes, snowboard, accessory sack) to the outside. I tested it with loads ranging from 15 to 25 pounds and settled on 20 pounds as a comfortable load carrying capacity (the maximum comfortable load an average person can carry in this pack all day). It’s well designed and highly versatile. It easily handled every task I put it to.

So, how does the Stratos 34 compare with the popular Atmos 35? The Atmos has an aluminum alloy frame, smaller internal hydration sleeve, and perforated foam shoulder straps and hipbelt for better ventilation. Its frame is stiffer and may carry more weight, but it has two side compression straps instead of the Straightjacket compression system. The lower compression straps extend over the side pockets, which is a nuisance, and the frontpanel comes to a point near the top, which is a bit funky.

I measured the weights of the Atmos 35 and Stratos 35 (in size medium) at 41.2 and 45.8 ounces, respectively. Bottom line, neither pack is really lightweight, so if weight is your most important factor in choosing a daypack you will probably want to look elsewhere. I personally feel that weight is not the most important factor in choosing a day pack, because you only carry it for one day at a time, and carrying a loaded day pack is good conditioning for backpacking. More important (to me) is selecting a pack that really fits well, carries comfortably, and has all the features I need, while keeping weight to a minimum. Based on these considerations, my choice of the two is the Stratos 34. I like its design and feature set better – it’s a very rugged, user-friendly, and versatile pack.

What’s Unique

The Stratos 34 AirCore frame with tensioned mesh backpanel is an innovative design that really works to provide a form-fitting backpanel with plenty of ventilation.

Recommendations for Improvement

I had to look hard to find any faults with the Stratos 34. It would be nice to have a small strap to hang a water bladder in the mesh backpanel cavity, rather than just dropping it in. It would be nice to have side hydration ports on the main compartment to work with the internal hydration sleeve. Overall, the Stratos 35 is heavier than I would prefer due to the use of heavier fabrics and plastic frame components, but every part is functional and this pack is built to last a lifetime.

Introduction

The Exposure 36 is the smallest of Osprey’s Exposure series, a line of packs designed to meet the needs of climbers and ski mountaineers. If you are heading out for an all day summit attempt, an afternoon of ice climbing, or a long slog through the backcountry looking for that perfect virgin slope, then the Osprey Exposure 36 might be just the pack for you. The Exposure 36 is jam-packed with features to help you carry the specialized gear of these activities, and packs them all into a well-built three pound package. But how about general use – is this a good all around 36 liter pack?

What’s Good

• Comfortable harness system
• Low profile keeps the load close to your back
• Many nice features for carrying skis and ice gear
• Haul loops and daisy chain are useful for alpine climbs

What’s Not So Good

• Small diameter main compartment makes this pack less friendly for general purpose use
• Low volume side pockets have limited utility
• Fabric won’t hold up to hauling

Specifications

Performance

I used the Osprey Exposure 36 in the Arizona mountains all winter. Winter here means cool weather for rock and alpine climbing – no ski mountaineering or ice climbing. Most of my trips have been general rock climbing, exploratory climbs and bushwhacks, and alpine style rock climbs on some of Arizona’s best peaks. The Exposure 36 is designed purely for these types of vertical pursuits.

Its most notable feature is the long, narrow design of the main compartment. This design keeps the weight of the pack load close to your body, and makes it easier to maneuver with the pack while climbing or skiing on steep terrain. The small diameter of the main compartment does limit the use of the pack. Certain gear just won’t fit very well into the pack – sleeping bags and ropes most notably. Osprey has included rope tie-ins under the lid to facilitate carrying a rope on the outside of the pack.

The low profile is a significant benefit if you must wear the pack while climbing, as I did while climbing the 3 pitches on the remote north face of Rincon Peak. Following moderate climbs such as Rincon Peak was easier with this pack than other packs with similar volume. The built in daisy chain is a great feature on long climbs. I hung the pack at every belay, giving my shoulders a rest and making it easy to sort through gear.

The gear loops that are built into the hipbelt came in handy a couple of times. But if I am using gear that might be stored on the gear loop, I am also probably wearing a climbing harness, which makes the gear loops redundant in those cases.

Another climbing feature included with the pack is the three point haul system. Three attachment points are sewn into the upper pack to ease the setup of a haul system. The haul loops make it easy to set up a haul, and they keep the shoulder straps from being used to carry weight during a haul. But don’t think that this makes the pack into a good small haul bag. I recommend you haul the pack only for very short distances when absolutely necessary, as the fabric on the Exposure 36 is not nearly as tough as the fabric on well-designed haul bags. The pack would be shredded very quickly on any significant haul that was less than vertical.

Carrying a big load is a delight with the Exposure 36. For a small volume pack, it can carry a lot of weight very comfortably. I found the harness system and hipbelt very comfortable, and could easily carry 25 pounds on the 3000 vertical foot approach to Rincon Peak. I also carried heavy loads out to local crags on several occasions – intentionally stuffing the pack with as much weight as possible, about 30 pounds. Even with this weight the pack was quite comfortable on moderate approach hikes.

The Exposure 36 has an HDPE framesheet that is accessible from a zipper in the main compartment. A single, full-length aluminum stay runs down the center of the framesheet. I found the frame itself to be comfortable, even after a long day of climbing. The Osprey ErgoPull hipbelt adjustment system is easy to use and applies pressure quickly and evenly across your waist. The ErgoPull system is noticeably lighter and less bulky than the large webbing and buckle systems on most climbing packs.

The Osprey Exposure 36 has a number of features to assist the ice climber and backcounty skier. Carry points are included for skis, snow shovel, and ice tools. Dual side compression straps help keep the load stable and close to your back; and a small pocket on the left side is designed to carry wands or snow pickets. Their small volume won’t carry much else besides energy bars or other small non-essential items.

A hydration sleeve is built into the main compartment, along with a hydration tube port at the top of the pack. The hydration sleeve will easily fit a 100 ounce reservoir. A clip in point to stabilize the reservoir is not included.

Overall, I found the Exposure 36 to be very good at what it was designed to do. It is my pack of choice for any day-long alpine outing. But it is too small for overnight trips and too heavy to carry along with another pack – so it is best suited for day outings. The specialized feature set, light weight and good load carrying capacity combine to make it a great choice for serious, day-long climbing ventures.

What’s Unique

The Osprey Exposure 36 has a strong combination of features for alpine climbing, ice climbing and backcountry skiing. At 3 pounds, it is lighter than most packs with these features and has a fair price ($129) for a pack with such an extensive feature set.

Recommendations for Improvement

Osprey has clearly designed the Exposure 36 for climbers. The Exposure 36 is well designed for a narrow range of activities, but a small increase in the diameter of the main compartment would increase the pack’s utility. By also including well-designed compression straps climbers would still get the load control they need.

Introduction

The Shadow 55L is a lightweight backpack that utilizes clever design and numerous attachment points to provide a pack capable of hauling heavy, dense loads. Its use of lightweight fabrics make it lighter than similar-sized climbing packs on the market. Is it the solution for lightweighters looking for a framed pack for heavier loads?

What’s Good

• Great frame and harness for heavy loads
• Rigid aluminum Y frame
• Lightweight self-healing body fabric
• Durable materials
• Removable dual-density foam backpanel doubles as sleeping pad
• Plenty of straps and tie-on points
• Removable lid and frame to create a lighter summit pack

What’s Not So Good

• Loaded down with straps and excess ‘features’
• Heavy for its capacity
• No side pockets

Specifications

Performance

At only 3360 cubic inches volume and weighing 3 pounds 12 ounces (my measurement) the Black Diamond Shadow 55L is outside the range that we normally consider lightweight. However it has a very capable frame and suspension system and is aimed squarely at the climber hauling heavy, dense loads.

The primary weight saving feature of the Black Diamond Shadow 55L is the use of a unique silnylon fabric. This is not the 1.1 oz/yd² silnylon beloved by ultralight tarp makers, but a much heavier diamond ripstop that has both a silnylon and a polyurethane coating. This material is claimed to have the remarkable ability to self-heal small punctures. I punched small holes with the awl on my knife and following a bit of massaging it was very hard to find the holes again. This self-healing was surprisingly effective for holes with up to 1/8-inch (3 mm) diameter. This fabric is rugged enough for normal use although it is not very abrasion resistant; and the parts of the hood that use the silnylon material have picked up minor damage from abrasion during testing. The wear areas on the body, lid, and base are well-reinforced with heavier fabrics.

The Shadow has a wide, stiff hipbelt combined with a large and firm lumbar pad to provide an excellent platform for transferring heavy loads to the hips. At first I found the combination a little uncomfortable, but after longer use I ceased to notice the stiff padding and it felt remarkably comfortable. The shoulder harness, while not as well padded as most on the market, is firm and capable of carrying a good bit of weight. Carrying 16 kilograms (35 lb), or more, the harness was remarkably comfortable. The pack is exceptionally solid and stable, which is a great feature in a climbing pack. The only time the load was less stable was when the pack was overfilled with the extension collar filled right up, then it became a little top heavy and inclined to swing around.

The Shadow has a one-size-fits-all harness that minimizes weight by eliminating extraneous adjustment straps and buckles. It has a torso length of 20 inches (51 cm) from the center of the hipbelt to the top attachment point of the load lifter straps. Black Diamond says it is suitable for people with 18 to 21 inch back lengths, which seems reasonable. At 5 feet 10 inches this back length fit me just fine; much taller or shorter people might struggle.

The main point of a pack is to carry a load comfortably, so a little extra weight can be forgiven if a pack carries exceptionally well. Here the Shadow excels. The 4.2 ounce rigid Y frame provides great support, even under heavy loads exceeding 50 pounds. The volume is only 3360 cubic inches (55 L) with an extra 1300 cubic inches (21 L) in the extension collar, however a load has to be pretty dense before you can fit 50 pounds into the pack. Of course there is the opportunity to strap things on the outside, and the Shadow 55L has lots of unique attachment features. Instead of a crampon patch it has two straps with clips, and for ice tool attachments it has a little sleeve with clips at the bottom and bungees at the top. These straps are generally useful for climbers and well thought out, but they all contribute to the weight. The lightweight backpacker who only occasionally takes ice tools and crampons might wish for simpler, lighter, traditional attachment straps.

The floating lid is attached with two straps that can usually be clipped with one hand – a nice touch. The lid can be instantly unclipped to form a little daypack. Unfortunately the straps supplied are too short for use as a daypack and there aren’t others on the pack that can be scrounged for the purpose.

Apart from the lid, the pack has no external pockets; not even a stub pocket for anchoring snow stakes or poles. The main pack has two internal full-height pockets, one for a foam backpanel pad and one for the aluminum Y frame and a water bladder. I felt a terrible ultralighter’s urge to start cutting out this extra fabric.

The Y-frame has my pet peeve – plastic end protector caps that become unglued from the aluminum and get lost in the innards of the pack when the frame is removed. The frame is held in place by big Velcro tabs that seem redundant. The frame is most easily removed by gently flexing it from the pockets.

The foam backpanel pad has two layers, a 1/8-inch (4 mm) thick closed cell foam and a stiffer white foam material of the same thickness. In a pinch the pad can be unfolded to form a sleeping mat 44 inches long.

While the foam pad (which tapers from 11.5 to 10.5 inches wide) is a little narrow for a comfortable sleep, it is enough to make all the difference on a forced bivy. Like many packs with removable padding, getting the foam and Y frame back into their tight pockets is a bit of a struggle and not something to look forward to on a cold morning with clumsy fingers. At bit of practice at home is warranted.

The pack has one neoprene reinforced hydration port (which needed enlargement with a knife to fit a mouthpiece through) and a bungee on the shoulder to hold a drink tube.

The pack can be stripped down to 42.6 ounces for use as a summit pack by removing 16.3 ounces of lid and frame. The hipbelt is not removable. The weight breakdown of the unmodified pack is given in the table below.

Compared to similar packs in the Backpacking Light Gear Guide this is a mid-priced pack with a midrange weight. Where it stands out is its attachment points for climbing gear and its weight carrying capacity.

What’s Unique

• Little Velcro tags to keep the straps out of harm’s way
• One-handed fastening of the main compartment straps
• Aluminum Y-frame
• Dual-density foam backpad
• Self-healing silicone and polyurethane coated nylon

In the final analysis this is a fairly heavy pack for its volume by today’s lightweight standards. However it is a very capable load carrier, and for dense climbing loads that exceed the capacity of a frameless pack this may be just what you need.

Recommendations for Improvement

Some further refinements I would like to recommend are:

• End caps that stay attached to the frame
• More attention to saving weight – trim excess fabric around seams, use fewer layers of fabric in the harness, and eliminate one of the internal pockets

Introduction

New for 2006, the frameless GoLite Rodeo at 1500 cubic inches (23 liters) is labeled as a snowboard pack. It has a snowboard sleeve and MP3 player holder, which makes it rock for snowboarders, but it’s versatile enough for a lot of other uses. How does the Rodeo rate as a general snow sports pack, or year-around pack?

What’s Good

• Lightest snow sports pack we know of
• Two panel-loading compartments
• Case for MP3 player or ultra compact digital camera
• Zippered water-resistant hipbelt pockets
• Sheds rain and snow
• Pockets for valuables, goggles, shovel
• Sleeve for avalanche probe or shovel handle
• Excellent construction and durable
• Versatile enough to use as a general-purpose daypack

What’s Not So Good

• Limited volume for extended winter day trips
• Limited weight carrying capacity because of its frameless design and thin/soft shoulder straps and hipbelt
• Hydration system only, no water bottle pockets
• No ski loops (but skis can be carried on the sides)
• Hipbelt pockets are not easily accessible

Specifications

Performance

Since the GoLite Rodeo pack has a snowboard sleeve, it would be easy to label it as strictly a snowboard pack. But that would be unfair. For one thing, the snowboard sleeve is easily detached with four side-release buckles, yielding a versatile pack with two panel compartments on the front. For another, other gear (such as skis, snowshoes, a gear bag, or whatever) can easily be attached to the frontpanel instead of a snowboard. In my testing process, I approached the Rodeo with an open mind to see what it could or could not do well.

The Rodeo is essentially a frameless backpack. It does have a 1/8-inch thick flexible foam framesheet that provides a little rigidity, but it is not capable of transferring weight to the hipbelt by itself. For weight transfer to occur, the pack body needs to be stuffed tight with gear to create a “virtual frame” that transfers weight to the hips through its rigidity.

Four contoured mesh-faced foam panels sewn to the backpanel provide padding and channels for ventilation. The contoured shoulder straps are wide (2.5 inches) but they are thin (1/4-inch) and soft, which is good and bad. Their width helps to distribute weight, but their thinness and softness are not conducive to carrying heavier loads. Similarly, the hipbelt consists of two short lightly padded wings attached to a 1.5-inch mesh belt. Since the Rodeo does not have an internal frame, pack weight is split between the shoulder harness and hipbelt, and its weight carrying capacity depends on your ability to carry weight on your shoulders.

The Rodeo has several features that make it a specialized winter sports pack, but do not interfere with it functioning as a good general purpose daypack. There are two panel-loading main compartments. The inner compartment is mainly used to stow clothing and has a water-resistant zipper to keep moisture out. It has a hydration sleeve and a fleece-lined pocket for goggles inside. The outer compartment has a sleeve inside for an avalanche probe or shovel handle. A snow shovel with a detachable handle will fit inside, plus a few small clothing items.

Outside pockets on the Rodeo are a mixed bag. There is a zippered security pocket at the top of the pack, a good place for valuables. On one of the shoulder straps there is a neoprene foam pocket for an MP3 player or ultra compact digital camera (anything larger is a tight fit). I found the location good for convenience and keeping the electronics out of the snow when I set the pack down. Each hipbelt wing has an attached zippered water-resistant pocket to conveniently stow smaller items. However, when the pack is on, the hipbelt pockets are located under your elbows, so they are not easy to access. Each side of the pack has a small tool pocket and hold-down, which can be used for ski or trekking poles.

Note that hydration with the Rodeo pack is by hydration bladder only. There are no side pockets to carry water bottles. In the wintertime this approach actually works better – the hydration bladder is against your back to keep the water warmed, and an insulated sleeve on your delivery hose (not included) keeps water from freezing.

The most noticeable feature on the Rodeo is the snowboard sleeve on the frontpanel. Rather than a gear cradle, which is attached at the bottom, the sleeve is open on four sides and is attached with two straps and four quick-release buckles. I tested it with a snowboard, backcountry skis, and snowshoes and found that it handles a snowboard or snowshoes well. A snowboard slips under the sleeve, while snowshoes can either be secured to the face of the sleeve or under it. Each strap has two neoprene patches to grip items and prevent them from sliding.

Skis are best carried on the sides of the pack so they don’t interfere with walking. Since the pack does not have ski loops, I attached them under the panel straps on the sides of the pack. This arrangement worked, but was far from ideal because the skis blocked access to the panel-loading pack.

As far as roominess, I found the Rodeo’s 1500 cubic inches (23 L) adequate to pack my normal cold weather alpine day tripping gear, but it was a tight fit. I would prefer an extra 500 cubic inches, part of it in the form of two durable X-pac lower side pockets instead of the small pole pockets.

Besides volume limitations, I have some concerns about the comfortable weight carrying capacity of the Rodeo. The pack weight with my normal winter day trip gear, including food and water, is about 12 to 13 pounds. Attaching a snowboard or backcountry skis adds another 8 to 10 pounds, bringing the total weight up to about 20 to 22 pounds. That kind of weight goes beyond the comfortable load carrying capacity of this pack. In contrast to GoLite’s rating of 25 pounds, I feel that the maximum comfortable load for the Rodeo is around 15 pounds, 20 pounds at the most. The pack does not have a frame, and the shoulder straps and hipbelt are too thin and soft for comfortably carrying weight. It gets down to how much weight you can comfortably carry on your shoulders.

Bottom line, the Rodeo is a lightweight in more ways than one. Although it is the lightest snow sports pack we know of, it is short on volume and weight carrying capacity. Most snow sports packs have an internal frame and a more substantial suspension system for carrying weight, which also make them relatively heavy for their volume. The Rodeo is designed to attach a snowboard, but doesn’t really have the weight-carrying capacity to carry it plus normal snow sports and cold weather gear. But the Rodeo concept still has hope. Its present design is suitable for carrying lightweight snowshoes. If a lightweight frame (like the corrugated plastic frame in the GoLite Vision Pack) and a more substantial suspension system were added, the Rodeo could do the job and still weigh significantly less than many other snow sports packs.

So how versatile is the Rodeo? The snowboard sleeve easily detaches with four side-release buckles to yield a fairly normal year-around daypack. The top pocket and two panel compartments allow good organization and convenient access. Its volume and weight carrying capacity are about right to carry everything needed for an alpine day hike, or to carry gear for yourself and a companion. The main deficiency is side pockets; I would prefer to have two durable side pockets mounted low to provide a space for water bottles and frequently used gear.

What’s Unique

The Rodeo is especially suited for carrying a snowboard, and it provides places to put specialized winter sports gear (avalanche beacon and probe, shovel, and goggles) to keep them handy.

Recommendations for Improvement

Although the Rodeo is lightweight and versatile, it falls short in the volume and weight carrying capacity needed for alpine day tripping carrying a snowboard or skis. Some specific recommendations are:

• Increase the volume to about 2000 cubic inches to provide adequate room for bulky cold weather clothing
• Add a lightweight removable framesheet (perhaps similar to the one in the Vision pack), and add more and stiffer padding to the shoulder straps and hipbelt
• Add durable lower side pockets for water bottles or convenient storage
• Move the hipbelt pockets from the side to the front to make them more convenient
• Add ski loops to the lower sides to make the pack more suitable for carrying skis