Welcome! Ultralight backpacking is my passion, and keeping up on new technologies, gear, and techniques relevant to UL backpacking is what floats my boat. I'm always looking for the lightest, most functional gear to improve a lightweight or ultralight backpacking kit, and report my impressions and field testing results here. For hikers wanting to keep up on the latest and greatest ultralight backpacking gear, this is a good place to hang out. Also, there is a lot of information here (and on our informational website Southwest Ultralight Backpacking) on useful techniques and backcountry etiquette -- food for thought for hikers wanting to lighten their load and their impacts.

My goal for Ultralight Insights is to understand, test, and report on new technologies and gear of interest to lightweight and ultralight backpackers. It's a passion after all, so we just plain enjoy talking about it. I hope readers will add their own wisdom and comments, respond to my questions, ask their own questions, and correct me if I get something wrong. Happy hiking! Will

Friday, July 1, 2016

GEAR REVIEW: 2016 Gossamer Gear Gorilla Backpack

By Will Rietveld

With some very significant improvements for 2016, the Gossamer Gear Gorilla is an outstanding backpack for lightweight backpacking, and it weighs just 2 1/4 pounds.

Author’s Note: Some readers may be confused because I published an earlier review of the 2016 Gorilla Backpack with a top flap rather than its present floating top pocket. The latter and other changes were implemented because of a decision to move production to a different factory. New features planned for 2017 were incorporated as the new factory set up to manufacture the Gorilla. In response, I have re-written this review for the real 2016 Gorilla Backpack.

The final version of the 2016 Gorilla adds a floating top pocket that is removable. Other important improvements include anchoring the frame to a stiffened hipbelt, lighter fabrics, and larger hipbelt pockets. (Gossamer Gear photo)


Since its introduction in 2009, the Gossamer Gear Gorilla backpack is now at gen 4. I have consistently given this pack an outstanding rating, so how can Gossamer Gear make it even better? Once more, the changes are both significant and functional, but the pack gains a little weight. How does that additional weight relate to performance?

At 40 liters the Gorilla is a medium size backpack ideal for lightweight backpacking, or ultralight backpacking with larger volume loads or longer trips. In either case it’s designed to comfortably carry up to 25 pounds; 30 pounds max. More on that later.

Interestingly, the Gorilla was previously rated at 46 liters, but the present version is specified at 40 liters. Has the pack been downsized? More on that later as well.

Specifications and Features

Gossamer Gear (www.gossamergear.com)
Gorilla 40 Ultralight Backpack
70 denier Robic ripstop nylon body, 100 denier Robic nylon in high abrasion areas, Air Mesh shoulder strap and hipbelt lining, Power Mesh fabric in sleeping pad sleeve, stretch mesh front pocket, tubular aluminum frame
Measured weight (size Large) 35.6 oz with stay and hipbelt; manufacturer specification 35.7 oz
Large mesh front pocket, 2 durable fabric side pockets, fitted floating detachable top pocket, 2 zippered hipbelt pockets, 4 side compression straps, hydration sleeve with 1 center hose port, 9-inch extension collar, drawcord top closure, trekking pole holders, removable corrugated Sitlight pad backpanel, sternum strap, ice axe loop, haul loop.
$245 with hipbelt

What’s New

There are six main changes in the new 2016 version of the Gorilla, and all of them are significant:
  1. The contoured tubular aluminum frame now connects to the hipbelt
  2. The hipbelt has been stiffened to make it more supportive
  3. The top flap has been replaced with a fitted and floating top pocket
  4. The hipbelt pockets are larger and gusseted
  5. Lighter weight Robic fabrics are used in the pack’s body and reinforcements
  6. One center hydration tube port replaces two corner ports, and there are three reservoir hang loops rather than one


In previous versions of the Gorilla, the one-piece U-shaped tubular aluminum stay merely resided in sleeves on the backpanel. It served as a pack stiffener, but it was not an integrated internal frame. The 2016 Gorilla is finally a true internal frame backpack, with the ends of the stay anchored in sleeves on the back of the hipbelt.

 A layer of semi-stiff plastic has been added to the hipbelt to make it stiffer, so it now works in concert with the connected stays to improve weight transfer and carry comfort.

The former Over-The-Top closure system (a top flap with a shallow zippered pocket) has been replaced with a floating top pocket that is removable. This adds some additional volume.

The hipbelt pockets are a big improvement over the old ones. While the previous pockets were two dimensional, the new ones are three dimensional with a 1.5-inch gusset. The overall dimensions are significantly larger.

Lighter weight Robic fabrics are used to partially offset the weight added by the top pocket; 70 denier in the pack body (previously 100 denier), and 100 denier for reinforcements and high abrasion areas (previously 200 denier).

Eliminating one hydration tube port also saves a smidgen of weight.

Overall, these are very significant improvements. The previous versions of the Gorilla were really good, now it is outstanding. The Gorilla is now a very refined backpack, and still retains Gossamer Gear’s DNA for lightweight and functionality.

However, adding features and design improvements adds weight. While the original Gorilla weighed just 24.2 ounces, the gen 3 (2014) upgrade added about 4 ounces, now the gen 4 improvements add another 7.4 ounces and bump the weight up to 2 pounds 3.6 ounces (for size Large). That’s acceptable, if the increased weight translates to improved performance. Read on.

Photo Tour

Frontpanel View: With its new top pocket the new Gorilla is a bit taller; I measured it at 32 inches with the extension collar full. Note the large capacity mesh front pocket,and durable fabric side pockets.

Backpanel View: The backpanel retains the signature egg crate patterned Gossamer Gear SitLight pad in a stretch nylon sleeve. The pad is easily removable for sitting on during breaks as well as camp use. The shoulder straps are contoured to fit both men and women and are lined with Air Mesh for ventilation. Note the much larger capacity hipbelt pockets.
Side View: This view again shows the size of the front mesh pocket and side pockets, as well as a good look at the new top pocket. Each side has two compression straps that provide excellent pack volume adjustment.

Top Pocket: The top pocket is floating, meaning it's height can be adjusted depending on how full the pack is. It is also removable when it is not needed. In that case the top straps are connected in an X-pattern. The pocket has a full width zipper for easy access. It adds some significant volume to the pack in a very convenient location.

The side pockets are large enough to hold two water bottles, and have an elastic binding to help keep them from sliding out when you bend over. The photo also shows the size of the hipbelt pockets when fully expanded.


I tested the Gorilla on 14 trips, carrying loads ranging from 15 to 30 pounds. (Photo by Tom Galbraith)

From my testing, I can say unequivocally that the upgrades (1 and 2 above) in the new Gorilla’s frame and suspension system result in a very noticeable improvement in the pack’s load transfer and carry comfort. With loads under 25 pounds, the pack will transfer all of the weight to my hips and carry it very comfortably. At 30 pounds the pack puts about one-fourth of the weight on my shoulders, which is still comfortable, but I can feel the weight more. The sweet spot is 20 to 25 pounds.

The new hipbelt pockets are wonderful compared to the old ones. I could barely get my compact camera in the old ones, but the new pockets have loads of room.

And the new top pocket is golden. The net weight increase is small, but it adds some very useful volume in the right place. The top pocket is perfect for stowing a jacket or rainwear.

Another less obvious benefit of the new floating top pocket is it actually increases the usable volume of the pack (see the frontpanel photo above). While the previous Over The Top flap shielded the top of the pack well, it was also part of the closure system which included the upper part of the extension collar. The new floating top pocket and drawcord closure allows the extension collar to be completely filled, and the top cap sits on top of that. In summary, the floating top pocket plus the additional usable volume in the extension collar contribute significantly to the Gorilla's volume, and it's space not apparent in the pack's 40 liter volume specification.

I don’t mind the switch to lighter fabrics. Robic fabric is extremely strong; see my description here. Frankly, its hard to tell the difference from the previous Gorilla.


This latest version (2016) of the Gorilla really rocks. I was impressed with most of the previous versions (except gen 2 which eliminated the side compression straps), but this latest version simply gets everything right. It’s clearly more comfortable to carry and transfers weight better. The previous top flap, which kept water from entering the pack, was an improvement, but the zippered pocket in the lid was not all that useful because it’s flat and tight. The floating top pocket is the right solution, and it adds some needed volume.

One quandary is the volume of the pack. As I mentioned, the previous Gorilla was claimed to have 46 liters and the latest version is specified at 40 liters. I checked the volume of the main compartment compared to the Gen 3 Gorilla to verify that the pack has not been downsized (actually I found it to be 2 liters larger). So what gives? Much of the confusion, I believe, resides in applying the ASTM F2153 standard, which specifies that an internal frame pack’s volume is based on the volume of the main compartment; the volume of attached pockets (which is variable) is not included.

However, it’s common practice for manufacturers of ultralight gear to detail the volume of the main compartment and all pockets, so a potential buyer can determine if her gear kit will fit in the pack and where specific items might go. I believe Gossamer Gear should stick with that practice to help buyers with the pack selection process.

But the volume conundrum begs more clarification. As specified, the Gorilla at 40 liters is only 4 liters larger than the Murmur, but it is clearly a larger pack. In practice, the Murmur is right-sized for ultralight backpacking, and the Gorilla (in my opinion) is right-sized for lightweight backpacking. However, the 40 liter specification gives the impression that it is smaller than it actually is. We at least need more complete information on the actual volumes of the main pack body and all pockets.

The Gorilla is just right for a summertime backpacking trip with lightweight gear and shorter trips. I should disclose, however, that there were occasions with the previous Gen 3 Gorilla where I came up short on volume when packing bulkier loads. That should be less of an issue with the roomier Gen 4 2016 Gorilla. One technique to free up interior space is to attach tall gear bags to the sides of the pack, under the side compression straps. That technique will allow the Gorilla to suffice for most lightweight backpacking trips.

Some buyers will opt for the larger Mariposa pack to ensure they have enough pack volume. The Mariposa, 60 liters and 34.8 ounces, actually weighs one ounce less than the Gorilla and costs only $10 more, which makes it very tempting. However, a partially full pack does not carry as well as a fully expanded pack, and the Mariposa does not have side compression straps to adjust it for smaller loads, so I caution against getting the Mariposa “just to make sure I have enough volume”. Better to determine the actual volume of your gear kit, add 25-30% for food, water, and fuel, and then purchase a pack with that volume.


  1. Good review Will. A couple questions. I tend to carry two Smart water bottles in the side pockets, has that capacity changed? With the decrease in central compartment can the pack still carry a small bear canister?

    1. Hi Doug, The side pockets are wide enough to carry 2 Smartwater bottles in each pocket. I don't have any answer yet on the volume issue. I don't think the pack itself has shrunk, just the specification. I don't use a bear canister, so I can't comment about the fit, sorry.

  2. Good review. I want this pack. But if you need more room go to the Mariposa. I've been using Google this pack for 4 hears now and love it. But it really is bigger than I need for even extended trips. I think this pack hits the sweet spot.

    1. I agree with you Lee. A LW backpacker should be able to fit her gear kit into this pack, or continue to reduce weight and bulk until it does. The Mariposa doesn't cost much more than the Gorilla, so many people opt for the larger pack. One of the most frequent questions GG gets is "what size pack should I get"? Perhaps GG should have a video showing what will fit into a Gorilla and what will fit into a Mariposa. A full Gorilla will carry better than a partially full Mariposa.

  3. Will this work for winter snowshoes day hikes or should I look elsewhere?