The Gossamer Gear G4-20 Backpack is a 42-liter frameless roll-top backpack that weighs 25 oz. Being frameless it’s best for carrying loads under 20 to 25 pounds and makes a nice ultralight backpack for multi-day trips and extended day hikes. In many ways, the G4-20 repackages many of the unique features of Gossamer Gear’s Classic Mariposa 60 Backpack in a lower volume and lighter weight form for hikers who want its utility without its weight or added volume.
Specs at a Glance
- Type: Frameless
- Top Closure: Roll top
- Weight: 25 oz (includes 3.3 oz external sit pad)
- Pockets: 5 + main compartment
- Gender: Unisex
- Ice ax loop: 1
- Trekking pole holder: No
- Hydration compatible: Yes, center ports but no internal pocket
- Bear Canister compatible: Yes, vertical
- Sizing: Three fixed torso ranges and hip belt lengths
- For additional specs click for Gossamer Gear product page
The G4 incorporates a number of design elements that are common on Gossamer Gear’s other backpacks. It has a front stretch pocket that’s good for storing clothing layers and other items you want easy access to during the day. There’s an external sit pack pocket and a foam sit pad that’s nice to sit on when you want to take a break, although it has holes in it so its no longer waterproof like Gossamer Gear’s other sit pads. Finally, there are gear loops distributed along the seams of the pack where you can clip on items or attach cord/cord locks (sold separately) to create compression or shrink excess pack volume.
Modular Roll Top
The G4 has a roll top that can be secured with buckles and webbing straps to the sides of the main compartment or on clipped together on the top and held in place with a single top strap. All of the straps are removable, so you can choose which ones you prefer and remove the excess straps or keep them all in place. (Note: the side straps and the top strap are not interchangeable.) The roll-top is a good option, especially for a lower volume pack, compared to the over-the-top closure used on Gossamer Gear’s other packs, which can be awkward and to open and close if you need to access the main compartment frequently or prefer the simplicity of a roll top.
In use, I’ve found that the side straps are awkward to use and run slack unless the pack is fully loaded, while the top strap is easier to use when the pack is partially loaded. The top strap is also useful if you want to carry a folding foam pad on top of the pack.
The pack comes with 5 pockets total including 2 hip belt pockets(described below), plus the main compartment. There is a map-sized pocket on the front of the pack above the stretch mesh pocket that has a waterproof zipper and is large enough to hold your personal items from ski goggles to keys, wallet, and electronic devices. It’s pretty handy.
There are two more pockets on the sides of the main pack bag, one 6″ tall and the other 10″. Both can hold two Smartwater bottles. You can reach both pockets while wearing the pack, although it’s much easier to pull bottles out of the shorter pocket unless you’re really flexible. The tall pocket is reminiscent of the tall quiver-style pocket on the Mariposa 60, but is much more accessible when the pack is worn. It’s good for stashing long thin objects like fishing rods or a Jetboil stove system. Both pockets have drainage holes in their bottom.
Fixed Length Hip Belt
The G4 comes with a fix length hip belt that is sewn directly to the back of the pack and not removable or interchangeable like most of Gossamer Gear’s other backpacks. That said, the hipbelt size ranges offered have a lot of overlap and you should be able to get a good fit anyway. I still wish that the hip belt was removable because that’s a nice feature on a frameless backpack, but if that’s something you want, I suggest that you look at the Gossamer Gear Kumo 36 instead.
The hip belt has two pockets. One is large enough to store a phone and closes with a waterproof zipper, while the other is an open mesh pocket good for storing snacks and items you don’t mind losing.
The G4 is a unisex backpack with J-shaped shoulder straps. Plastic loops have been added to the shoulder strap that are compatible with Gossamer Gear’s shoulder strap pocket and other clip-on gear like an inReach Mini Satellite Messenger. I would prefer having daisy chains sewn to the front of the shoulder straps because they’re compatible with a wider range of pack pockets, but it’s not a show-stopper as they say.
Gossamer Gear lists the G4’s max load at 30 pounds, but I think 20-25 pounds is a more realistic range. While the foam pad helps the hold its shape and the hip belt is sewn onto the pack, the G4 is still a frameless backpack and doesn’t transfer much to weight to the hips. The hip belt is wide and richly padded but it isn’t firm enough for significant weight transfer. This is totally in-line with what I expect from a frameless backpack, but it’s important that you understand that the G4 is an ultralight backpack and has a limited load capacity by design.
Comparable ultralight frameless backpacks
|Make / Model||Volume||Weight||Fabric|
|Zpacks Nero||38L||10.9 oz / 308 g||Dyneema DCF|
|Waymark EVLV Ultra||38L||14.4-22 oz / 408-624 g||Ultra|
|SWD Ultralight Superior Frameless||45L||18.2 oz / 516 g||Ultra|
|Gossamer Gear Kumo 36||36L||20.5 oz / 581 g||Robic Nylon|
|LiteAF Ultra Curve 30||30L||13-19 oz / 368-538 g||Ultra|
|Northern Ultralight Sundown||48L||18.6 oz/ 526 g||XPac|
|Mountain Laurel Designs Burn||38L||16.5 oz / 467 g||Dyneema Gridstop Nylon|
|Gossamer Gear G4-20||42L||25 oz / 709 g||Robic Nylon|
|Nashville Packs Cutaway||40L||14.2 oz / 402 g||Ultra|
|Atom Packs EP40||40L||15.4 oz / 437 g||Ultra|
The Gossamer Gear G4-20 is a 42-liter frameless backpack that’s fun to use because it’s suitable for so many different types of trips from ultralight thru-hiking and hut-to-hut trekking, to all-day peakbagging adventures and fast-and-light overnights. It’s a roll-top backpack making it simpler to use than most of Gossamer Gear’s other packs, with a permanently attached hip belt, and lots of pockets, which distinguishes it from Gossamer Gear’s other frameless backpacks. The G4 is heavier than many other frameless backpacks because it has a hip belt, making it a good choice if you prefer one on a backpack but want to shed some gear weight. That said, it’s important to understand that the G4-20 is a frameless backpack with a maximum load of 20 to 25 pounds, so you can’t carry as much weight as a similarly sized backpack with an internal frame or frame stays
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