Overview – Frameless Backpacks State of the Market Report 2011

Much has changed since our last Frameless Backpack Review Summary published back in 2004 and our Superultralight Backpacks Review Summary published in 2006. Although the fundamentals remain the same, the number, diversity, and features available in frameless backpacks have greatly expanded. Our 2004 article contained just seven packs, and our 2006 article contained five packs. Today we have lots of choices, so it’s entirely possible to find exactly the pack you want in terms of fabric, sizing, volume, and features. The challenges are to determine exactly what you want and to find it.

A lightweight frameless backpack is a core component of a lightweight backpacking kit, whether you choose to travel superultralight (SUL, base weight less than 5 pounds/2.3 kg), ultralight (UL, base weight less than 10 pounds/4.5 kg), or lightweight (LW, base weight less than 20 pounds/9.1 kg). The base weight is everything but consumables (food, water, and fuel). Pack total weight with consumables for SUL backpacking should normally be less than 12 pounds (5.4 kg), less than 20 pounds (9.1 kg) for UL backpacking, and less than 30 pounds (13.6 kg) for LW backpacking. Stronger people can carry more, but most people prefer less. It’s best to keep weight under these limits if you expect to comfortably carry a frameless backpack. The guiding mantra is “less is better.”

To carry a light load, all you need is a light pack, so a frameless backpack is the pack of choice for backpackers who’ve gone lightweight. Frameless backpacks have become very sophisticated and do their job well. However there is a great diversity of users, backpacking conditions, and specific needs and preferences. To accommodate such a diversity, manufacturers offer frameless backpacks with a wide range of volumes, weights, features, and load hauling capability. To cover the range of packs and uses, we divide the topic into five articles as follows:

• Lightweight Frameless Backpacks State of the Market Report 2011: Part 1 – Choosing and Using a Frameless Backpack (this article) We discuss the fundamentals of selecting and properly using a frameless backpack, and provide specifications for all packs included.
• Lightweight Frameless Backpacks State of the Market Report 2011: Part 2A – Technical Evaluation – Measurement of Pack Volume and Volume Reduction Capability Reports our measurements of actual pack volume and the extent that pack volume can be reduced to accommodate smaller loads.
• Lightweight Frameless Backpacks State of the Market Report 2011: Part 2B – Technical Evaluation – Measurement of Pack Load Carrying Capacity Reports our pack torso collapse measurements using different pack loads to determine the comfortable load carrying capacity.
• Lightweight Frameless Backpacks State of the Market Report 2011: Part 3 – Packs for Ultralight Backpacking We provide specifications for midsize frameless backpacks popular for ultralight backpacking, rate them according to relevant criteria, and identify the standouts for different situations and needs.
• Lightweight Frameless Backpacks State of the Market Report 2011: Part 4 – Packs for Lightweight Backpacking and Load Hauling We provide specifications for larger volume frameless backpacks popular for lightweight backpacking, rate them according to relevant criteria, and identify the standouts for different situations and needs .

Introduction to Part 1: Choosing and Using a Frameless Pack

By definition, a frameless backpack lacks the support of a built-in internal frame. Today’s frameless backpacks are not just a bag with shoulder straps attached, i.e., a rucksack. Rather, they are highly refined for lightweight backcountry travel, a specialized piece of gear that requires the use of specialized techniques to attain its benefits. A frameless backpack is not for everyone, and hikers unwilling to adopt the proper usage techniques, or overload them, are not likely to be happy with a frameless backpack.

The classic frameless backpack consists of a rectangular main compartment, a large front mesh pocket, side mesh pockets, an extension collar, rolltop closure with top compression strap, padded shoulder straps, sternum strap, and most now have a padded hipbelt. This feature set has withstood the test of time, and the design of most frameless backpacks is some version of this fundamental feature set.

Also, some frameless backpacks have available (or included) removable stays or a removable rigid foam framesheet, which adds another dimension to the capability of these packs. With the stays installed, manufacturers claim these packs can comfortably carry heavier loads, but there are a few caveats to be aware of. Packs with removable stays are included in this state of the market report, and we will discuss the use and benefits of removable stays.

The successful use of all frameless backpacks is dependent on the protocols explained in this article (I can’t emphasize that enough!).

Backpackers who are lightening their pack and want to enter the unburdened world of ultralight backpacking should thoroughly read the following sections.

Creating a “Virtual Frame”

Successfully using a frameless backpack requires you to master certain packing protocols so the pack effectively transfers weight to the hips and carries a load comfortably. The pack needs to be properly loaded and compressed. A basic principle for using a frameless backpack is to create a “virtual frame” which provides frame-like rigidity in the backpanel. A virtual frame is created by the combination of:

• Choosing a pack with volume that matches the volume range of gear plus expendables (food, water, and fuel) you commonly carry.
• Coiling a closed cell foam (CCF) sleeping pad around the inside of the pack’s interior, or folding it and placing it against the pack’s backpanel.
• Proper packing so higher density gear and food is against the mid and upper backpanel.
• Tightening all compression straps so the pack is a firm unit.

The gist of this is that you want your pack to be stiffened as much as possible so it effectively transfers weight to the hips, increasing the comfortable load carrying capacity of the pack by reducing the weight carried on the shoulders. The importance of this technique increases with the amount of weight carried.

A key factor in this equation is the use of a closed cell foam sleeping pad inside the pack to help attain stiffness. You can test it for yourself by packing your gear kit in a frameless pack with or without a folded CCF pad against the backpanel, then going on a short hike. The CCF pad makes a huge difference!

You may be thinking: “I don’t use a CCF pad anymore, I switched to a lightweight inflatable sleeping pad, so what do I do?” That’s a common conundrum when it comes to the virtual frame concept. You will find some good ideas in the next two sections.

Pack Compression/Volume Reduction

As mentioned, a good compression system is required to make the pack a firm unit. A superultralight backpack doesn’t need much of a compression system because it is usually stuffed tight and is very light. However ultralight and lightweight backpackers, who carry loads of varying volume and weight, need to choose a backpack with a good compression system.

I don’t particularly care for a bungie system on the front of a frameless backpack because it overlays the pack’s mesh pockets and interferes with access to the pockets. For compressing the pack to reduce volume and tighten the load, a bungie system works well, as long as the elastic cord is heavy enough and you compress the pack before you fill it. If you fill a pack before you compress it, a bungie system provides “soft” compression (it stretches more than it compresses), while webbing straps provide “hard” compression (no stretch).

My preferred volume reduction system is webbing compression straps on the sides of the pack. Two compression straps on each side are adequate for a smaller volume pack, and three compression straps per side are better for larger volume or taller packs.

Key points for pack compression/volume reduction:

• This capability is more important when you choose a pack that is significantly larger than your gear kit, and for larger frameless packs in general.
• A good compression system provides the means to firmly tighten the pack around its contents on three sides (top and two sides).
• An excellent compression system has compression capability on all four sides, with two or three well placed compression straps on each side.
• An elastic bungie system will effectively reduce pack volume, if you compress it before you fill it, but it interferes with access to the pack’s outside pockets.
• An alternative to volume reduction is volume-filling, coiling a slightly inflated inflatable sleeping pad inside an oversize pack to take up volume.

Removable Stays

I chose to include packs with removable stays in this state of the market report because these packs are fundamentally frameless backpacks with an accessory consisting of sleeves on the inside of the backpanel that accept contoured flat or tubular stays. The purpose of the stays is to increase pack stiffness; they do not create an internal frame backpack because the stays are not solidly anchored to the hipbelt to directly transfer weight to the hips.

Some manufacturers claim their frameless backpack with stays inserted is capable of carrying loads up to 35 pounds (15.9 kg). There is a very important caveat to this; these packs are capable of carrying heavier loads if (and only if) the stays are used in combination with a confined folded closed cell foam pad against the backpanel. That combination can provide a significant boost in a pack’s comfortable weight carrying capacity, to 25 to 30 pounds (11.3 to 13.6 kg) in some cases. To the extreme, there are pack makers who claim their pack will comfortably carry 50 pounds (22.7 kg) (Mithril) or even 100 pounds (45.4 kg) (Kifaru), but let’s get real – for lightweight backpacking there is no reason to carry those outrageous loads, there is nothing comfortable about carrying 50 to 100 pounds (22.7 to 45.4 kg), and if you do there are better packs to help you manage the load. What they really mean is that if you can actually carry that weight, the pack will also carry that amount of weight without busting a seam!

Many hikers these days have switched to a lightweight inflatable sleeping pad, so they don’t have any need to carry a closed cell foam sleeping pad. How do you create a virtual frame without a closed cell foam pad? If a frameless pack has excess volume, a partially inflated inflatable pad can be coiled inside the pack to take up the excess pack volume, and our test results show that it can effectively create a virtual frame. However, a simpler and better approach is to select a properly sized frameless pack with removable stays to stiffen the pack; the stays basically provide the same function as a folded closed cell foam pad against the backpanel.

Do removable stays help you carry heavier loads more comfortably? The answer is a definite yes. In our measurements of pack torso collapse with different loads, reported in Part 2B of this series, we found that all packs that have removable stays will more comfortably carry a heavier load with the stays in, some better than others. But, again, it’s important to know that removable stays do not create an internal frame pack; they simply stiffen a frameless pack (just as a closed cell foam pad does to create a virtual frame) to help it resist pack torso collapse. And stays in combination with a CCF pad provide even more support. We also found that a confined rigid closed cell foam pad in the backpanel of some frameless packs (like the GoLite Peak, Jam, and Pinnacle) performs the same function.

Our tests of packs with and without stays support the conclusion that removable stays are a beneficial option and enhance the versatility of a frameless backpack. A high percentage of the packs in our roundup – even smaller volume packs – offer removable stays. As pack volume increases, the need for a supplementary removable stay system increases, so we feel that larger volume frameless backpacks should definitely include removable stays or at least offer them as an option. You may be thinking: “beyond a certain pack volume, why not simply use a lightweight internal frame backpack?” That’s an alternative, but there is still a weight penalty. Our tests show that the best larger volume frameless backpacks, with stays inserted, can match the comfortable load carrying capacity of a lightweight internal frame backpack, and the packs are significantly lighter.

Key points for removable stays:

• For a small weight increase (less than 5 oz/142 g), removable stays add a lot of versatility to a frameless backpack.
• Stays help to stiffen the pack; they don’t create an internal frame pack.
• Stays in combination with a coiled or folded CCF pad significantly boost a pack’s comfortable load carrying capacity.
• If you use an inflatable sleeping pad instead of a closed cell foam sleeping pad, stays compensate to stiffen the pack.
• Backpanel stays help you carry loads heavier than 15 pounds (6.8 kg) more comfortably (see our testing results in Part 2B of this series).
• Stays help maintain pack torso length.
• Stays can be shaped to match the curvature of your back to improve pack fit.

Pack Volume

It’s ironic that we usually know the exact weight of our gear kit (we weigh everything, right?), but we don’t bother to measure the stuffed volume of our kit. And knowing the volume is a key factor in choosing the proper size backpack. It’s important to choose a frameless backpack that matches the volume range of your normal gear kit plus food, water, and fuel for a typical trip. The reason for this is explained in the paragraphs above; you want your pack to be full and firm, as much as possible, so it carries well. For example, I live close to a large wilderness area and go on frequent fast and light two- or three-day trips. My ultralight gear kit plus food ranges from 2500 to 3000 cubic inches (41 to 49 L) and 15 to 18 pounds (6.8 to 8.2 kg), so my preferred pack volume is in the 2500-3000 cubic inch (41 to 49 L) range.

For many ultralight backpackers, the “sweet spot” is about 2500 to 3200 cubic inches (41 to 52 L) of volume. A well thought out ultralight backpacking kit plus expendables for a shorter trip (up to four days) will easily fit into a pack at the lower end of that range. Gear for cooler temperatures and/or a longer trip will fit into a pack at the upper end of the range. Some thru-hikers prefer a backpack up to 3600 cubic inches (59 L) so they have the extra volume needed for occasional long hauls. The important factor here is higher volume packs used for ultralight backpacking need to have excellent compression capability so pack volume can be adjusted effectively for various size loads.

Many hikers are not consistent on trip type and length, and their pack load varies a lot. What then? The options are to own smaller and larger volume packs, or choose a pack at the high end of the ultralight backpack volume range (around 3500-3600 cubic inches/57-59 L) that has excellent compression capability (explained above) so pack volume can be adjusted as needed. I have tested both approaches, and I personally prefer multiple packs, but that’s more expensive. The latter option is quite workable, but it’s important to choose a pack with excellent compression capability.

A common mistake is to overestimate the pack volume needed, and consequently purchase a pack that is larger than you really need. Many hikers don’t really know the actual volume of their gear kit, and the volume is probably lower than they think. To avoid the mistake of choosing a pack that is too big (or small), I recommend that you actually measure the volume of your gear kit, as shown in the photos below.

I took this exercise a step further by packing the same gear kit (shown above) into the GoLite Peak pack, which is 2440 cubic inches (40 L) for size Large. Again, it all fit leaving the entire extension collar free. Since the extension collar on the Peak is smaller, there is only room for three or four days of food. The mesh outside pockets on the majority of these packs expand to hold a lot of gear, and I typically put at least a third of my gear in the outside pockets so it’s handy. Overall, it’s safe to say that most frameless backpacks will actually hold more volume than specified.

Key points for pack volume:

• Don’t blindly choose a pack size!
• It’s important to measure the volume of your typical gear kit.
• The volume of your gear kit is probably smaller than you think.
• Frameless backpacks often provide more room than their specifications would indicate.
• Choosing a pack whose volume matches the stuffed volume of your gear kit is a good rule of thumb; there should be enough remaining volume for food for several days.

Okay, now that we have done our part to determine the pack volume we need, can we safely assume that manufacturer specified pack volumes are accurate? The short answer is no. It’s not as straightforward as it should be, because: 1) the volume sometimes varies with the pack size selected: 2) manufacturers vary in how they measure pack volume and what’s included: and 3) unfortunately, manufacturer volume specifications are inaccurate in many cases, as we find in Part 2A of this series. For some pack brands (for example, GoLite), the volume increases as the pack size increases, so there is about a 125+ cubic inch (2 L) difference between pack sizes. However, for many of the other manufacturers of frameless packs, the pack volume is the same for all pack sizes; they simply attach the shoulder straps higher or lower.

The variation in pack volume measurement methods among manufacturers makes it difficult for the buyer, because quite frankly the actual volume can vary substantially from the specified volume. In Roger Caffin’s Lightweight Internal Frame Backpacks State of the Market Report, he found that American made backpacks had 21.1% less volume than specified, which is quite significant. There is an ASTM standard and guidelines for measuring pack volume, using 20 millimeter hollow plastic spheres (essentially ping pong balls), but as Roger points out, there is quite a bit of variation in how the standard is applied (or not applied).

The situation for frameless backpacks is different. Most of the frameless backpacks in this roundup are made by American companies, and most are small businesses, so we would expect even more variation in the methods they use to determine pack volume. Many simply use pack dimensions to calculate volume, and there’s a lot of differences in whether outside pocket and extension collar volume is included or not. The de facto standard for frameless backpacks is to include all pockets and the extension collar in total pack volume, and itemize the volume of the pack components (main compartment, exterior pockets, extension collar). Ultralight and lightweight backpackers need to know these numbers, and the numbers need to be accurate. Unfortunately, that is not necessarily the case; our pack volume measurements reported in Part 2A of this series reveal some big discrepancies, indicating that frameless pack manufacturers need to adopt a consistent protocol and more accurately measure pack volume.

Proper Fit

The standard procedure to measure your torso length is as follows: have a friend measure your back along the spine from the level of your iliac crest (the top of your hipbones) to your C7 vertebrae (the knobby bone at the base of your neck). It helps to mark those spots with a pen or marker, then measure the distance. Most pack manufacturers have an illustration on their website to help you understand where to measure. If you are between two sizes, size up.

This assumes that you will wear a backpack hipbelt on your iliac crest (top of the hipbone). However, if you find it more comfortable to place a hipbelt either higher or lower, a pack should be fitted to your specific support points. For example, the top of my iliac crest has a steep angle, so wearing a hipbelt at the top of my iliac crest is too high, so I prefer to place the hipbelt lower, which means that my torso length is longer than the standard measure would indicate. Consequently, a size Large pack fits me better than a Medium. What doesn’t work is to choose a pack size based on the standard measure of user torso length, and then wear the pack either higher or lower than your iliac crest.

A proper fit, defined as the pack torso length matching the user torso length, is important for optimum pack performance. The hipbelt should wrap around the top of your hips, and the top of the shoulder straps should attach to the pack at the top of your shoulders. If a pack has load lifters, they should angle up to their pack attachment at a 45 degree angle. It’s okay for the pack torso length to be a bit more than the user torso length, but not less. The shoulder straps should not wrap over your shoulders and down to the pack attachment. The “wrap over the shoulders” fit may be acceptable for a day pack, but not for a backpack.

A pack that is too short (pack torso length less than the user torso length) results in pack lean-back, which is explained as follows. The proper procedure to put on a pack is to loosen the shoulder straps and hipbelt, put the pack on, tighten the hipbelt in its proper place, then tighten the shoulder straps (and load lifters if your pack has them). If the pack torso length is too short, tightening the shoulder straps will put much of the pack’s weight on your shoulders. After hiking a while, shoulder fatigue sets in and the remedy is to loosen the shoulder straps, which causes the top of the pack to lean back. This shifts pack weight to the hips and relieves shoulder discomfort, but the pack’s center of gravity is moved outward. Bottom line, this is not a proper fit and not the best way to carry a backpack, and can be avoided by purchasing the correct size pack in the first place.

Things I learned from testing backpacks for this article are: 1) the method manufacturers use to measure pack torso length can be misleading, 2) the actual pack torso length for a given pack size can vary significantly among manufacturers, and 3) an underfilled or overweighted pack can result in pack torso collapse, which amounts to a reduction of the pack’s torso length of at least one size.

Most manufacturers measure pack torso length from the top of the shoulder strap attachment to the bottom of the hipbelt. This is easy to measure, but (in my opinion) the resultant pack torso length comes out to be longer in relation to how user torso length is measured and how the pack is worn. In my opinion, a more meaningful pack torso length measurement would be from the underside of a shoulder strap to the middle of the hipbelt. Finally, the actual torso length of a given pack size can vary significantly among manufacturers. When I measured the actual torso length of all the size Large packs I tested, I found a rather wide range. The bottom line is to make sure a pack fits properly.

Key points for proper fit:

• Measure and keep a record of your torso length.
• Do your research and choose a pack that fits properly; it’s better to err on the tall side rather than getting a pack that is too short, which will put more weight on your shoulders.
• An underfilled or overweighted pack can cause pack torso collapse, which reduces the pack’s effective torso length by one size or more (a Large becomes a Medium, for example).

Fabric Choices

Interestingly, there are no frameless backpacks made of spinnaker fabric in this roundup, probably because it has proved to be too fragile. Spinnaker fabric, weighing about 1 ounce per square yard (34 g/m²), was previously the lightest fabric available in a frameless backpack, for example the Gossamer Gear G5 and G6 Uberlight packs. Overall, frameless backpack fabrics have moved up a notch in durability. The lightest fabrics available now are Cuben Fiber, silnylon, and PU coated ripstop nylon. The first two are nearly equivalent in weight because a heavier, more durable version of Cuben Fiber (CTF3, 1.4 oz/yd²/47.5 g/m²) is required for a backpack. Pack manufacturers who use Cuben Fiber claim that it has much higher puncture and tear resistance than silnylon. According to Ron Bell at Mountain Laurel designs, silnylon warp tear strength is about 12 to16 pounds per square inch (0.8 to 1.1 kg/cm²) and Cuben Fiber CTF3 is 190 pounds per square inch (13.4 kg/cm²). The differences are demonstrated in this video by ZPacks:

At the more durable end of the range are the Dyneema ripstop fabrics, which are basically a 210 denier ripstop nylon containing a grid of Dyneema fibers. Dyneema and Spectra are nearly identical; Dyneema is made by DSM in the Netherlands, and Spectra fiber is made by Honeywell in the United States. The difference among Dyneema fabrics is in the fabric weave and amount and orientation of Spectra contained. Manufacturers have assigned names like Dyneema Gridstop, Dyneema Ripstop, Dyneema Diamond, etc. to the fabrics. Dyneema X, exclusive to Mountain Laurel Designs and Thru-Hiker, is described as “4 oz/yd² (136 g/m²) 210d Nylon with a white 210 Dyneema ripstop grid and 0.25-inch (0.6 cm) reinforcement at 0 and 90 degrees. The high Dyneema content equals 9% of total fabric weight. Each Dyneema thread is 15 times as strong as steel by weight. An additional X pattern of nylon overweave improves abrasion and tear resistance.”

Fabric choice depends on how you will use the backpack. Silnylon and Cuben Fiber are the fabrics of choice for the lightest packs that will be used for superultralight or minimalist ultralight backpacking, where every ounce counts. For general ultralight and lightweight backpacking, I recommend the Dyneema ripstop fabrics because they are the best balance of light weight, durability, cost, and longevity. A Dyneema ripstop pack can last a lifetime, while a silnylon or Cuben Fiber pack has a limited lifespan. According to Joe Valesco at ZPacks, “Cuben Fiber eventually begins to fray from excessive sun exposure and general use. This is what limits the lifespan to 2500 to 3000 miles. You will likely have duct tape on some frayed areas by the end of a long thru-hike.” To illustrate the weight difference, let’s take an example: the basic ZPacks Blast 26 backpack (2600 cubic inches/43 L) weighs 7.4 ounces (210 g) when constructed of Cuben Fiber or Silnylon. The same pack constructed of more durable Dyneema X fabric adds 4.4 ounces (125 g), for a total weight of 11.8 ounces (335 g), which is still very light.

All this said, it still seems like we have not found the “perfect” fabric for an ultralight frameless backpack. Silnylon and Cuben Fiber don’t have the longevity, and 4 oz/yd² (136 g/m²) Dyneema ripstop seems like overkill. It would be nice to have a 2 oz/yd² (68 g/m²) Dyneema ripstop? Also, Invista is introducing a new UltraLite line of Cordura fabrics in the 30 to 100 denier range; perhaps we will start seeing those fabrics in ultralight frameless backpacks in the near future.

Key points for fabric choices:

• Cuben Fiber used for backpacks is stronger than silnylon and weighs about the same, but you still pay a premium to get it. It makes the most sense for a superultralight pack.
• Dyneema is a good balance of light weight, durability, cost, and longevity. A pack made of Dyneema ripstop is recommended for general ultralight and lightweight backpacking.

Which Features?

Nowadays a full range of options is available, so with some research you can find exactly what you want. The choices range from a minimalist pack with very lightweight or removable features, to a full-featured durable pack, or one where you can select your desired fabric and features ala carte. Many packs are a predetermined design (e.g., GoLite and Gossamer Gear), where the manufacturer has optimized the pack with a tested feature set they perceive will satisfy the majority of hikers. Other manufacturers (e.g., Mountain Laurel Designs and ZPacks) offer a basic pack design with your choice of fabric and additional features. And these companies are masters at designing features and accessories that are very lightweight and removable, so it’s entirely possible to configure a pack to your liking and still hold the weight down to 15 to 20 ounces (425 to 567 g).

It all gets down to personal preference. While reading reader’s comments, I notice a full spectrum of individual preferences. Two schools of thought are the “clean design” and the “functional design.” The clean design eliminates outside pockets and accessories that can get shredded over time, but requires taking the pack off to access needed items. A functional design includes the traditional front and side mesh outside pockets, hipbelt pockets, and even shoulder strap and sternum strap pockets, to accommodate a “do it on the fly” philosophy for maximum convenience. I subscribe to the latter philosophy because I want to access things on the go, and I am gentle on gear, but I realize that there are many people and hostile conditions that are hard on gear, requiring the former approach.

Obviously durable fabric and features add weight, and it is up to the buyer to evaluate the weight/benefit tradeoffs and decide which pack and options best meet his or her needs. This is an important decision because, after all, frameless backpack users are ultralight backpackers and every ounce matters. We are always confronted with weight versus benefit decisions and our objective is always to minimize weight while getting in as many benefits as possible. If you get carried away with adding features, you can be accused of thinking like a lightweight backpacker (sorry for the jab there!), who has a hard time doing without gadgets, features, and comfort/convenience items.

Key points for features:

• Do your research and decide which features you really need or want (there’s a difference between the two).
• Think of features in terms of weight and functionality, not art.
• Every ounce matters.
• Choose carefully.
• Once you buy it, the shopping is done, and you own it.

Proper Packing

Most of the above factors come together in this section. Properly packing a frameless backpack (or one with removable stays) is important, and it needs to be taken seriously. How you pack determines how well a pack fits and how comfortably it carries a load.

Here’s the drill:

• Size up how much room your load will require in your pack. If it will fill it up completely, good; if it’s smaller than the pack volume, compress the pack first to reduce its volume. The goal is to fill the pack so it is firm and filled to about 2 to 3 inches (5 to 8 cm) above the shoulder strap attachment.
• Coil your foam or inflatable sleeping pad inside the main compartment, or alternatively fold it and place it against the backpanel (my preferred method).
• If you have excess volume in your pack, you have two options: 1) tighten the compression straps and then load the pack; or 2) if you use an inflatable sleeping pad, partially inflate the pad inside the pack to use up volume.
• Pack your gear inside the coiled pad, placing denser/heavier gear and food against the backpanel in the upper two-thirds.
• Pack soft gear around hard items to stabilize them and keep them from rattling against each other.
• Again, be sure to load the pack into the extension collar about 2-3 inches above the shoulder strap attachments. If you don’t make it, start over, or get it right next time. A tall firm pack is better than a short soft one.
• Snug down all compression straps.

This creates a firm pack with a virtual frame that carries well and will more readily transfer weight to the hips. The whole packing process, and the result, is better if you use a pack whose volume matches the volume of your gear plus food. The extra pack volume for longer trips should be the remainder of the extension collar.

Key points for proper packing:

• Matching pack volume with gear volume greatly simplifies the packing process; simply load your pack and you’re good to go.
• If pack volume is greater than gear volume, you need to use the pack’s compression system to reduce pack volume before you load it, or alternatively fill the extra volume by partially inflating a sleeping pad.
• Follow the steps above to properly load the pack.
• It’s important to load the pack 2 to 3 inches (5 to 8 cm) above the shoulder strap attachment to avoid pack torso collapse at the top.

What Really Matters

A frameless backpack is just one item in an ultralight backpacking kit. A lot of effort is required to plan such a kit that meets all of your needs and is still very lightweight (base weight under 10 pounds/4.5 kg). It’s important that your backpack matches your kit in terms of volume, features, and weight carrying capacity. Never choose a frameless backpack, even one with removable stays, if your base weight is over 20 pounds (9.1 kg) or total weight is normally over 30 pounds/13.6 kg. To comfortably carry those loads, you need a lightweight internal frame backpack.

Although most “enlightened” backpackers would argue for “the lighter the better,” there is room for pragmatism here. For me, I am a happy hiker if my total pack weight is under 16 pounds (7.3 kg). I really don’t notice the weight of my pack up to that point, but I progressively do notice it above that threshold. Glen Van Peski would not agree with this!

Finding the ideal frameless backpack gets down to doing a lot of research, evaluating the options, and making a wise decision. My experience from using a frameless backpack for over 13 years, reading numerous forum comments, and testing numerous frameless backpacks is that everyone’s perspective, situation, and needs are different, and everyone needs to make their own personal decision on which pack to buy. To help with that decision, in the sections ahead I provide comparative specifications for all of the packs included in this state-of-the-market report, and evaluate them in Parts 3 and 4 of this article.

Selection Criteria

This state of the market report focuses on frameless backpacks larger than 2000 cubic inches (33 L), which are suitable for superultralight, ultralight, and lightweight backpacking. The roundup also includes some larger volume backpacks capable of carrying large volume/moderate weight loads. I also include packs with optional removable stays, and comment on the functionality of the stays.

Overall, the selection criteria are fairly simple:

• Currently available.
• Frameless, nothing stiffer than closed cell foam in the backpanel.
• Pack volume greater than 2000 cubic inches (33 L).
• Pack volume to weight ratio greater than 80 in³/oz (138 cm³/g), based on manufacturer provided volume and weight data.
• Packs with removable stays are included and evaluated with and without the stays.
• Packs for specific uses other than backpacking (like climbing and adventure racing) are not included.

Specifications

The following table contains (in alphabetical order by manufacturer) specifications for all of the frameless backpacks included in this state-of-the-market report. For comparability, the weight of packs that have removable stays is for the pack only, without the stays. In subsequent articles in this series, the packs are divided into three groups, based on total volume, for superultralight, ultralight, and lightweight backpacking.

Footnotes:

¹ M=Men’s, W=Women’s, U=Unisex.

² Manufacturer specified total volume for size medium, including outside pockets.

³ Manufacturer specified weight is used for comparison because we were not able to obtain all of the packs and weigh them. For packs with removable stays, weight listed is without stays.

⁴ Derived by dividing pack volume by pack weight, this value indicates how efficiently a manufacturer has selected materials to reduce weight. A high value indicates very lightweight materials and fewer accessories. Also, larger volume packs generally have a higher volume to weight ratio.

⁵ Laufbursche (a small company in Germany) is currently (April 2011) accepting pre-orders for their packs, and expects to fully open for business by the time this article publishes. Listed prices for their packs are converted to US Dollars as of April 2011.

⁶ The Mithril pack is designed by Dr. George Cole at Kiskil Outdoor and manufactured by Moonbow Gear.

⁷ Rodney’s Packs (a small company in the Philippines) sells frameless packs in a variety of designs, either pre-made and posted for sale on his website (http://www.freewebs.com/litepacks/), or custom packs to buyer’s specifications.

Specifications Discussion

There are a total of 43 backpacks listed in the table, nearly four times as many as our previous roundups combined. All of these packs can potentially be used for superultralight, ultralight, or lightweight backpacking, but some are more suited than others. Note that the ZPacks Zero packs are stuffsack packs intended for superultralight backpacking – a stuff sack with shoulder straps; the addition of outside pockets or other accessories adds weight.

Two-thirds of the backpacks are mid-size (2400 to 3600 cubic inches/39 to 59 L), appropriate for ultralight backpacking, which makes sense since that is the most popular use. However, when I measured the volume of the packs I tested, there were a few surprises (read Part 2A for details), which resulted in some “midsize” packs being moved into the “larger volume” category, which is more suitable for lightweight backpacking.

The popular Granite Gear Vapor Trail is sometimes mistaken to be a frameless backpack. It does in fact have an internal frame consisting of a HDPE plastic framesheet plus a closed cell foam pad that is sewn-in and not removable. The Vapor Trail is now discontinued, but will be replaced by the Vapor Trail 2 in spring 2012. The new Vapor Trail 2 will resemble the current Blaze pack, will weigh about 2 pounds (0.9 kg), and will possibly have a removable framesheet.

Another source of frameless backpacks is Rodney’s Packs (http://www.freewebs.com/litepacks/index.htm). Rodney Liwanag, located in the Philippines, makes custom frameless backpacks utilizing numerous designs and fabrics. He often sews up a batch of packs of various designs and displays them for sale on his website. His packs are not included in subsequent parts of this report because he does not have any standard packs. Most of his packs are traditional designs; one of particular interest is his scaled down “Gossamer Gear G4-like” pack with 3000 cubic inches (49 L) of volume.

Fanatic Fringe appears to be out of business. We will miss their lightweight and inexpensive Alpine Trail pack for superultralight backpacking and Thompson Peak Pack for ultralight backpacking.

Notice the large number of frameless packs that have optional or included removable stays. As discussed earlier, this low-cost feature provides some distinct benefits, and adds more versatility to a frameless backpack. Our torso collapse tests in Part 2B of this series reveal that removable stays significantly improve a pack’s comfortable load carrying capacity, leading to the conclusion that removable stays should be an option on all larger capacity frameless backpacks.

The table also includes some large volume packs, for example the GoLite Pinnacle and Kifaru packs, which I call load haulers. These packs go beyond the volume actually needed for lightweight backpacking. I include them with packs suitable for lightweight backpacking in Part 4 and discuss their pros and cons. There is a point where it simply makes sense to purchase a lightweight internal frame backpack, or not, and I discuss that conundrum in Part 4.

Preview to Parts 2, 3, and 4

As you can see from the specifications table, there is a wide range of frameless backpacks differing mainly in volume, fabric, and weight. To compare them in this “bulk” listing would be totally meaningless, like comparing apples, bananas, and grapefruit. So, they will be divided into appropriate use categories based on their volume and weight. In Parts 2A and 2B of this state-of-the-market report, our technical evaluation of a group of thirteen packs provides a basis for separating the packs into appropriate groups based on use, and provides data for performance rating the packs. In Part 3 we focus on packs suited for ultralight backpacking, presenting appropriate background, specifications, ratings, and picks for specific situations and needs. In Part 4 we do the same for lightweight frameless backpacks.