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Mountainsmith Apex 80 Backpack Review

The Mountainsmith 80 Backpack

The Mountainsmith Apex 80 Backpack is a high volume, expedition-style appropriate for long backpacking trips where you need to carry extra food or technical gear. With an adjustable length torso, the Apex 80 is loaded with all of the features you’d expect on a high volume top-loading pack, but it is surprisingly lightweight (4 pounds 13 ounces) and far less expensive than competing packs from other manufacturers.

Organization and Storage

The Apex 80 is configured like many expedition sized backpacks with a floating top lid and high-capacity main compartment, including two zippers that provide access to the contents of the main compartment so you can access buried gear without having to unload the entire pack.

Front zipper provides access to everything in the upper half of the main compartment.
Front zipper provides access to everything in the upper half of the main compartment.

The first zipper is located on the front of the pack and opens into a mesh compartment where you can store frequently accessed items. The mesh pocket has a rear zipper running down the middle which provides access into the main compartment to anything stored in the top half of the pack. The mesh provides better visibility into the contents of the pack, but you wouldn’t want to store wet gear here.

Another zipper is located at the base of the main compartment where most people are likely to store a sleeping bag. However, instead of a sleeping bag compartment, there’s a flap inside the main compartment which can be used to create a shelf between a sleeping bag and the gear stored above it. The shelf is suspended by webbing hooks inside the main compartment but can be folded out-of-the-way if you prefer not to use it. This gives you a lot more flexibility in how you pack your gear.

Cavernous main compartment with a large extension collar
Bottom zipper provides access to gear stored at the base of main compartment.

While you’d think having a separate sleeping bag zipper at the base of a high-volume pack would be a good thing, I’ve never understood why backpack manufacturers encumber a pack with extra zippers (which jam and fail) if they can be avoided. Particularly since most backpacks seams are not waterproof and packs must be lined with a plastic bag to keep their contents dry, blocking external access.

Cavernous main compartment with a large extension collar
The Apex 80 has a cavernous main compartment, with a long extension collar capable of swallowing an additional 16 liters of gear, bringing the pack’s total extended volume to 96 liters (5858 cubic inches).

The Apex 80 features a generously sized top pocket and floating lid which can be used to attach more gear to the top of the main compartment and held in place by cinching the lid tight or simply strapping it down with the piece of webbing that provides top compression. In addition, the pack has a long extension collar capable of swallowing an additional 16 liters of gear, bringing the pack’s total extended volume to 96 liters (5858 cubic inches).

Large side pocket and bottom mesh bottle pockets
Large side and bottom mesh bottle pockets

Finally, the Apex 80 has two large zippered side pockets and two mesh bottle pockets on each side of the pack. While the bottoms of the mesh pockets are covered with heavy fabric for better durability, large weave mesh pockets like this are quite prone to tearing when caught on vegetation.

The shoulder straps slide up and down aluminum stays in the pack backpanel, allowing you to adjust the torso length fo ran optimum fit.
The shoulder straps slide up and down aluminum stays in the pack back panel, allowing you to adjust the torso length for an optimum fit.

Backpack Frame and Suspension

The Apex 80 is an adjustable frame backpack that gives you the ability to adjust the torso length, something you really need on a heavily laden expedition pack to ensure that most of the load rests on your hips and not on your shoulders.

The torso length is adjusted by raising or lowering the height of the shoulder straps which slide along two exposed aluminum stays in the back of the pack. The adjustment is controlled using simple webbing straps which are tightened or loosened, providing a no-fuss solution. Still, you’ll need to experiment with the fit because there aren’t any predefined torso length markings provided if you already know your torso length.

The aluminum stays are augmented by a plastic sheet sewn into the body of the pack that forms the pack’s frame. A mesh woven fabric covers padding on the back of the frame with a deep, central air channel that helps dry perspiration. When carrying a heavy expedition backpack, you perspire considerably more than when carrying a lighter load.

The Apex 80 hugs your back, providing very efficient load to hip transfer.
The Apex 80 hugs your back, providing a very efficient load to hip transfer.

The base of the frame has an articulated lumbar pad which catches onto your sit bones and enhances load transfer. While some people like lumbar pads and some people hate them, the lumbar pad does an effective job of bringing the load closer to the powerhouse at the top of one’s hips. That’s one of the things that I really like about this pack, that it really hugs your back closely, making load-carrying by your big core muscles considerably more efficient than a pack that pulls you backward.

The body hugging fit is further enhanced by load lifer straps which can be adjusted to match the pack’s torso length. Most lower volume backpacks have load lifter straps that can’t be repositioned at the point where they attach to the front of the shoulder, rendering them useless for long torso lengths. But the front load lifter buckles on the Apex 80 can be raised or lowered down the front of the straps if you change the torso length, ensuring a 30 to 45 degrees strap angle. You only find this feature on expedition size backpacks, which is unfortunate, because many backpacks in the 50-65 liter range would be substantially improved if they had it too.

Adjustible load lifter straps ensure a propper webbing angle even when the torso length is raised or lowered.
Adjustable load lifter straps ensure a proper webbing angle even when the torso length is raised or lowered.

Unfortunately. the hip belt wing on the sides of the Apex 80 has a tendency to sag when you crank up the load over 50 pounds. The wing pads are cut so that they can move independently of the lumbar pad. The resulting gap between the two areas of padding can result in hip belt slippage in people with squarish hips, transferring the weight off the hip belt and onto the shoulders.

The side wings of the hip belt move independent of the lumbar pad.
The side wings of the hip belt move independent of the lumbar pad.

Compression and External Attachment System

The compression and external attachment system on the Apex 80 is fairly simple and straightforward. There are two tiers of side compression straps, above the bottle pockets and above the top pockets, that do an excellent job of pulling the load closer to your pack. However, these compression straps have limited utility as external attachment points when the top pocket between them is full of gear.

Short diasy chains are provided for lashing gear on the outside of the pack and are position for optimal load transfer just above the top of the sleeping bag compartment.
Short daisy chains are provided for lashing gear on the outside of the pack and are position for optimal load transfer just above the top of the sleeping bag compartment.

There is a second pair of webbing straps that runs under the sleeping bag compartment and can be used to hold a cylindrical sleeping pad or tent. However, the straps cannot be removed if they’re not needed.

Short daisy chains are provided for lashing gear on the outside of the pack, just above the top of the sleeping bag compartment.

Finally, there is an ice ax loop and trekking pole loops at the base of the pack along with keeper straps higher up to secure the shafts.


The Mountainsmith Apex 80 is one of the lightest weight expedition sized backpacks available today (4 pounds 13 ounces)  and while it has a number of features that minimalist backpackers might sneer at, it’s a relatively streamlined backpack, unencumbered with many of the unnecessary features that weigh down other high volume packs in its class. With a lightweight, but adjustable frame and excellent perspiration ventilation, the Apex 80 provides a comfortable body-hugging fit, although people with squarish hips may experience some hip belt slippage when carrying heavy loads. Priced at just over $200, the Apex 80 is an excellent value for the money, and well worth careful consideration is you need a high volume backpack for remote adventures.


  • Lightweight, easy-to-adjust torso length
  • Form-fitting pack shape hugs your body
  • Extension collars adds another 16 liters of capacity, bringing the total volume to 96 liters
  • Much lighter weight than other expedition packs with comparable volume and features


  • Side mesh pockets are more prone to tearing off-trail
  • Sleeping bag compartment serves no function if the inside of the pack is lined with a waterproof liner.

Manufacturer Specifications


  • Parallel Y-Frame adjustable suspension
  • Load distributing Lumbar Control Point pad
  • ICS Cup waist belt fitment (ICS – Iliac Crest Shelf)
  • Anvil Airway perspiration control system
  • Dual density shoulder straps
  • Delta Wing Compression™ belt adjustment system
  • Front panel pocket fits Ten Essentials with zippered access to main compartment
  • SlingShot™ detachable top lid converts into a lumbar pack or shoulder sling
  • Side panel mesh pockets fit most water bottle styles
  • Zippered side panel accessory pockets
  • Separate sleeping bag compartment with internal divider


  • Bar tack reinforcements
  • YKK® Zippers
  • 3M™ Reflective Cord
  • Twin T6 1” 6061 concave aluminum stays


  • 210d Duramax™ Junior RipStop Nylon
  • 420d Duramax™ Nylon
  • 210d RipStop Liner


  • 28” x 11.5” x 9.5” / 71 x 29.25 x 24 cm
  • Waist Belt Webbing: 1.5″


  • Volume: 4882 cubic inches / 80L
  • Extended Volume: 5858 cubic inches / 96L


  • Up to 75 lbs


  • 4 lbs 13 oz / 2.2 kgs (verified on the SectionHiker scale)

Fit Range:

  • Torso: 17″ – 22″
  • Waistbelt: 30″ to 54″

Disclosure: Mountainsmith provided Philip Werner ( with a sample Apex 80 backpack for this review. 

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  1. Thanks for the excellent review!

    I’m considering one of the smaller Mtnsmith packs with a similar suspension. Bummed to hear about the hipbelt sagging. I thought that might be an issue, but I almost never carry a load above 50 lbs so maybe it’s not a big issue.

    When I tried on the pack in the store, the lumbar pad seemed low. Unusually low. You could hardly notice it until you put some weight in the pack. It wasn’t uncomfortable, it was just different than packs I’ve had before. Still, it was strange to feel the weight of the pack down almost on my rear end. I couldn’t tell if it was a fit issue for me or if it was the intended way for the pack to work.

    Still, your qualified vote of confidence makes me want to give the Mtnsmith products a little more consideration.

  2. Mountainsmith makes excellent packs and probably has the best track record of any backpack maker out there. Just ask any Mountainsmith pack owner..they wear their packs for decades until the things disolve on their backs. :-)

    When testing this pack, I couldn’t help thinking that the hip belt would probably work a lot better on a lower volume version (where the depth of the pack is less, hence less back pull/sag) The hip belt on the apex 80 is fine until you start really loading it up and filling all that space with gear, so it makes sense that the sag would be less of an issue with a smaller volume version.

    If you experienced sag in the store, you should look very closely at your torso length and make sure you have the right sizing. I’m not sure if the smaller valume packs are adjustable like the apex 80. It could also be that your butt doesn’t ptovide enough “shelf” for the lumbar pad to hook onto. Personally, I prefer very lightly padded hip belts for packs up to 65 liters because I find that heavy padding interferes with sitting on my iliac crest (hip bones).

    All in all the Apex 80 is a very fine pack, but it has to fit well like any other pack out there. Oh and one more thing…if you have very bulky gear, but relatively light (say 40 pounds or less), like a huge synthetic sleeping bag and multiperson tent, the Apex 80 could be a good option. The volume is huge.

  3. Wow.. I have been backpacking for years, and just today understood why backpacks have a sleeping back compartment. I have always used mine, and I have never had any issues with a wet sleeping bag, but I didn’t realize that they were lined. Anyways, thanks for the great review as always..

    • They’re actually not lined. What you’re seeing there is the White Trash Compactor bag I line my packs with to keep the seems from leaking in rain or when I put it down on wet ground. This is a very common practice amongst backpackers.

      The funny thing about sleeping bag compartments is that they’re supposed to let you avoid unpacking your pack at night. But if you’re carrying a heavy load of food, which you’d expect in an expedition pack, you’d place it on top of your sleeping bag where you can carry it most efficiently. If you’re anywhere in North America, you will unpack that food (and everything else on top) every night to either hang it in a bear bag or store it in a bear canister far from your campsite.

      So these sleeping bag compartments really no make no sense at all since you’re going to unpack your pack every night anyway…..

      I figure this design is just a holdover from Europe where they don’t have bears.

  4. Love my Mountainsmith Approach 35 pack. Probably the best constructed pack I own most durable pack I own.

    Sadly, I don’t get to use it anymore as I’ve outgrown it by reducing my gear down to such a point that the pack is overkill. Still keeping it around to loan to friends for trips. Selling it would be a hard decision as its probably the only pack I have any sort of emotional attachment to.

  5. Hi Phillip,

    Thank you for the thorough review. I like the idea of the zips on the main compartment, but as you mentioned normally you would line your pack with a plastic bag to waterproof it, making the zips kind off redundant. I suppose you could line the inner pack and perhaps keep the first compartment for quick access to stuff that doesn’t require water proofing. The price and light wight of the backpack makes it a really attractive option and I will definitely be checking one out in store.

  6. I use the MountainSmith rain cover on my bag rather than lining it.

    It doesn’t add much weight, tucks neatly out of the way, and cinches down well enough that I’ve never had anything get wet unless I neglected to cover the thing at night and a storm swept in on me. Added bonus for not tearing as easily as liner bags leaving me with trash to pack out and no waterproofing.

    The only thing I have had issues with using it is the surprise spider (thankfully not of the venomous variety) mating season of my last trip. Not closing completely around the bag allowed the little bugger’s in to the suspension adjustment, but liners wouldn’t have helped there either.

    I still don’t think I’ve gotten them out of every little crack and crevice.

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