I love frameless backpacks, especially the really light ones. With a volume of 3800 cubic inches and weighing 8.1 ounces, the Gossamer Gear G5 Hyperlight backpack has a volume to weight ratio of 469 cubic inches/ounce. The Hyperlight achieves this remarkable statistic through the use of spinnaker fabric, which seems like tissue paper, but is surprisingly strong and durable.
- Very lightweight (huge volume to weight ratio)
- Spinnaker fabric is waterproof and strong for its weight
- Wide shoulder straps and hipbelt distribute weight
- Lots of outside pocket storage
- Very comfortable to carry with loads up to 20 pounds
What’s Not So Good
- Lack of compression straps makes it impossible to compress small loads
- No load control other than tight packing
- Roll top with Velcro closure does not secure well
- Too much volume for its comfortable load carrying capacity
- Inflatable sleeping pad slips out of the pad sleeve
|2005 Gossamer Gear G5 Hyperlight|
|Frameless, top loading, roll top with Velcro closure|
|S (16-19 in/40-48 cm torso), M (18-22 in/46-56 cm torso), L (20-24 in/51-61 cm torso)|
|3800 ci (62 L) all sizes, 2,800 ci main body + 400 ci extension collar + 600 ci pockets (46 L + 7 L + 10 L)|
|Size M tested. Measured weight of pack with optional sternum strap but without shoulder and hipbelt pads 7.3 oz (207 g), shoulder strap pads 0.4 oz (11.4 g), hipbelt pads 0.37 oz (10.4 g), total weight with all pads 8.1 oz (229 g); manufacturer’s specification 8.3 oz (235 g) with shoulder strap and hipbelt pads|
|Pack body, side pockets, shoulder straps, and hipbelt are 0.96 oz/yd2 (33 g/m2) spinnaker ripstop nylon; bottom is 210d (4 oz/yd2, 136 g/m2) urethane-coated nylon double wall ripstop; pad sleeve and front pocket are thin nylon mesh|
|Hipbelt, 3 outside pockets, optional sternum strap, removable padding for shoulder straps and hipbelt, external sleeping pad sleeve, haul loop, ice axe loop, 2 hydration tube loops|
Volume To Weight Ratio
|469 ci/oz (based on 3800 ci and a measured weight of 8.1 oz)|
Comfortable Load Carrying Capacity
|20 lb (9.1 kg) estimated maximum comfortable load an average person can carry all day in this pack|
Carry Load to Pack Weight Ratio
|39.2 (based on a 20 lb load and 0.51 lb pack weight)|
The Gossamer Gear G5 Hyperlight is basically the same design as their classic G4 pack, except it is smaller (3800 cubic inches versus 4600), lighter (8.3 ounces versus 17.3, manufacturer specifications), and constructed of lighter materials (0.96 oz/yd2 spinnaker ripstop nylon versus 2.2 oz/yd2 urethane-coated ripstop nylon). It’s a tried and proven design, with many refinements over several years.
Like most frameless backpacks, the G5 is designed to utilize a sleeping pad to stiffen the fully expanded pack to create a “virtual frame” to transfer some pack weight to the hips. On the G5, there is a mesh sleeve to slip your sleeping pad into to create the pack’s padded backpanel, as well as a virtual frame. I found that a stiff closed-cell foam sleeping pad works best for that purpose, much better than a limp inflatable pad, which adds little rigidity to the pack. I also found that the weak thin mesh allows an inflatable pad to slip out at the top.
With a total volume of 3800 cubic inches (2800 in the main pack body), the G5 had too much volume for my ultralight gear. I tried using up the excess volume by placing a partially inflated sleeping pad (Therm-a-Rest Prolite 3 Short) inside the pack against my back. That configuration solved my excess volume problem and resulted in a tighter, stiffer pack that carried better. However it does not eliminate two other basic problems, and introduces a third issue.
First, the G5 has no side compression straps to stabilize the load and adjust volume. As the volume of pack contents diminishes during a multi-day trip, the user has no means to reduce pack volume and keep the pack rigid. A partially inflated sleeping pad inside works, but many users of this pack will use a closed cell foam pad instead of an inflatable pad, and logically it should go into the pad sleeve. Placing a partially inflated sleeping pad inside introduces another issue: it moves the pack’s center of gravity outward, which increases torsional stresses on the body.
Second, the G5 roll top/Velcro closure does not secure the top of the pack very well (see top photo). The closure has Velcro hook tabs that attach to loop patches extending down into the side pockets. Gear (in particular a self-inflating pad) inside the pack inches up, pushing it open. The pack needs a top compression strap to secure the roll down closure, and to hold a sleeping pad packed in the interior in place.
The upshot is that the G5 works better if your gear volume matches the pack volume. One solution to the issues discussed above would be for Gossamer Gear to add an intermediate sized pack between the G5 and G6 Whisper Uberlight, with a volume of approximately 3000 cubic inches. A more tightly stuffed pack would transfer weight without the need for side compression straps. For a longer trip, the pack’s extension collar can provide the extra volume needed, and as pack volume decreases, the lower pack body can be packed tight and secured with a top compression strap. This is one approach to the pack volume issue, but bottom line, there is a need for an effective way to control pack volume other than owning multiple packs, and that means compression straps.
Like the G4, the G5’s shoulder straps and hipbelt are made of pack fabric and are wide (almost 4 inches) for distributing weight. Each strap has an opening (with Velcro closure) that allows the option of either placing clothing inside the strap for padding (thereby saving weight), or inserting lightweight foam pads (weighing about 0.2 ounce each) into the strap. The weight of the four foam pads adds up to 0.77 ounces (my measurement). I found them to be very lightweight and comfortable, and a better alternative to inserting and removing clothing items into/from the strap pockets.
The Gossamer Gear G5 sleeping pad sleeve (top left) uses your sleeping pad to create a padded backpanel (Gossamer Gear NightLight pad shown), and add rigidity to the pack. The roll top closure with Velcro fasteners (top right) does not stay in place very well, and there is no top compression strap. Shoulder straps (bottom left) and hipbelt have openings for inserting clothing for padding, or a provided foam pad can be inserted (shown). The pack front and sides are covered with pockets for convenient storage (bottom right).
Voluminous outside pockets on the front and sides of the G5 provide lots of convenient storage. The front pocket is mesh and the side pockets are spinnaker fabric. All have an elasticized hem at the top and plenty of bellowing for easy entry and lots of storage space. I stuffed an entire Tarptent (sans poles) into one of the side pockets (bottom right photo above). The side pockets have a mesh panel at the bottom for drainage.
The G5 is designed to stuff your sleeping bag into the bottom of the pack. The bottom balloons out when stuffed full, creating a “compartment” for a sleeping bag and insulated jacket. Nice idea.
For bear canister users, a 9-inch x 10-inch (650 cubic inches) canister will fit into the G5 if it is dropped in lengthwise, then turned to horizontal.
In my test of the G5’s structural load capacity (see related article link in right column on Quantitative Analysis of Backpack Suspension Performance by Ryan Jordan), I found that 1 inch of pack torso collapse occurs at about 20 pounds, shifting much of the pack weight onto my shoulders. Suspension comfort is very good because of the G5’s very wide, padded shoulder straps and hipbelt, sternum strap, and the hipbelt conforming well to the hips. My assessment of the G5’s comfortable load carrying capacity is 20 pounds, which is similar to many other frameless backpacks with a hipbelt. The actual amount will vary from person to person.
I consistently found that I could comfortably carry 15-20 pound loads in the G5 all day. With higher pack weight (and greater pack torso collapse), I tended to let the pack ride lower on my shoulders. I could have shortened the shoulder straps, but that made them tighter and increased the weight on my shoulders, which made it less comfortable to carry the pack all day. Carrying the pack lower on my back places the pack center of gravity close to my body center of gravity, which is less than ideal (its better to have the pack center of gravity a little higher), but I found that the pack was simply more comfortable to carry all day by letting it hang back some.
Many of my hiking friends referred to the G5 as my “tissue paper pack.” It may seem that way with its crinkly thin spinnaker fabric, but in fact the G5 is reasonably durable and will last a long time with prudent use and care. In several months of testing, I collected a few abrasions on the G5, mostly on the side pockets, but no serious damage.
Through the use of spinnaker fabric, the Gossamer Gear G5 Hyperlight has the highest volume to weight ratio (469 ci/oz) of any commercially available frameless ultralight pack we are aware of. (This excludes the low volume SuperUltraLight packs.)
Recommendations for Improvement
My primary recommendation for the G5 is to add some type of compression system to adjust pack volume as load volume shrinks during a multi-day trip. For the top closure, I suggest adding a lightweight top compression strap (perhaps an inverted “Y” strap). For side compression, providing loops for a bungee compression system (like the loops on the Mariposa Pack) may be a solution. Sewn in foam padding in the shoulder straps and hipbelt will remove the weight reducing option of using carried clothing in place of foam pads, but will slightly reduce pack weight for those who prefer foam pads over clothing in the straps. (A weight savings of 0.77 ounce is not attractive enough to many hikers to bother stuffing and unstuffing socks into the straps.) Finally, the sleeping pad sleeve needs to be re-designed so an inflatable sleeping pad does not slip out.