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The Ultimate Guide to the Exped Thunder 70 Backpack

Backpack Review

The Exped Thunder 70 is an internal frame backpack with an adjustable frame and panel loading access. Weighing 3 pounds 6 ounces (tested), it has a very comfortable hip belt which ensures excellent load transfer to the hips and a single external aluminum stay which prevents torso collapse with heavier loads. With daisy chains and numerous external attachment points, the Thunder 70 can be outfitted for a wide range of trips from extended backpacking and winter hiking trips to adventure travel.

Internal Storage and Organization

The Exped Thunder 70 has a classic alpine style pack design with a top floating lid, large main compartment and extension collar.

The Thunder 70 is a classic alpine pack with a floating top lid and main compartment, that tapers towards the base for better load control.
The Thunder 70 is a classic alpine pack with a floating top lid and a main compartment that tapers towards the base for better load control.

The main compartment can be accessed through the top of the pack using a conventional drawstring closure, but there are also two zippers along the back that provide panel style access to items anywhere inside the main compartment without pulling them out of the top. This is handy for big loads or when using the pack for travel. When pulling down the back panel, the side compression straps must be released.

The back panel can be released using two zippers, provided access easy access to gear buried deep in the main compartment.
The back panel can be released using two zippers, provided access easy access to gear buried deep in the main compartment.

The side access zippers are covered with wide rain flaps but do not have a zipper guard inside, so care must be taken when closing them to prevent snags with delicate fabric or stuff sacks. The top of the back panel secures to the pack with a wide velcro strip and has a wide rain awning covering it, however, it is possible for rain to leak into the main compartment if all of the components are not aligned properly, and through the seams which perforate the back of the pack. If hiking in rainy weather, my advice would be to line the inside of the pack with a trash bag or use waterproof stuff sacks for sensitive items.

Jackets and loose gear can also be pulled out one of the side zippers without undoing both compression straps.
Jackets and loose gear can also be pulled out one of the side zippers without undoing both compression straps.

In addition to panel access, each of the side zippers can be pulled down individually and items extracted or stuffed into the main compartment, as shown. This does not require unhooking the side compression straps and is possible when the pack is not loaded down with externally attached gear.

Hidden security pocket on the underside of the top pocket.
Hidden security pocket on the underside of the top pocket.

The main compartment can fit a black Garcia bear canister positioned horizontally, with plenty of room for extra gear. There is also a separate hydration pocket on the back panel of the pack, inside the main compartment.

External Storage and Compression System

With two side stretch mesh pockets, a rear shovel pocket, and large hip belt mesh pockets, the Exped Thunder 70 has an ample amount of convenient external storage for water bottles and gear you want close to hand.

While the side bottle pockets are made out of a tough stretch mesh, teh bottoms are not reinforced with additional fabric and are prone to tearing by surrounding vegetation.
While the side bottle pockets are made of a tough stretch mesh, the bottoms are not reinforced with additional fabric and are prone to tearing by surrounding vegetation.

The pack has two tiers of compression straps, including a set that can be threaded through the water bottle pockets, providing compression even if the pocket contains a bottle. The compression straps are also long enough to accommodate snowshoes strapped to the side of the backpack, although doing so renders the side pockets difficult to access.

The Exped Thunder 70 uses aluminum hooks to secure webbing rather than plastic buckles. Velcro webbing keepers are used to keep the pack's numerous straps under control and out of the way.
The Exped Thunder 70 uses aluminum hooks to secure webbing rather than plastic buckles. Velcro webbing keepers are used to keep the pack’s numerous straps under control and out-of-the-way.

Exped has chosen to use aluminum hook rather than plastic buckles to anchor all of the webbing straps on the Thunder 70 (with the exception for the torso adjustment strap). These hooks can be difficult to adjust in cold weather while wearing gloves but are adequate for securing gear as long as there is good tension on the straps.

There are two daisy chains running down the back of the pack, which include elastic shaft holders, and provide users with the ability to strap all kinds of external gear to the back of the pack, provided they have additional straps to attach it with. There are also numerous tie-outs around the perimeter of the top lid and at the base of the pack for lashing on additional gear.


The Exped Thunder 70 can be adjusted for people with different torso lengths, by raising or lowering the shoulder straps along the central aluminum stay which runs up the center of the pack. While this system works well when the proper fit is dialed in, the lack of sizing information on the webbing strap can make the fitting process difficult for less experienced pack users who don’t know how to tell if the distance between the shoulder harness and the hip belt “feels” too long or too short. It’d be nice is the webbing strap was labeled with numbers that indicated torso length in inches and centimeters.

The Thunder 70 has an adjustable frame where torso length is adjusted by raising or lowering the shoulder harness using a webbing strap.
The Thunder 70 has an adjustable frame where torso length is adjusted by raising or lowering the shoulder harness using a webbing strap.

The only “frame” element on the Thunder 70 is the central aluminum stay, shown above. Despite this, the pack performs admirably with heavy loads, with little noticeable lateral sway or torso collapse when heavily loaded. Load transfer to the hips is excellent, in part because the hip belt is attached directly to the base of the stay, and because the pre-curved foam padding provides excellent contact with the hips, The fit of the hip belt is also enhanced by the use of a Scherer cinch (tightened by pushing the hip belt straps forward), which provides mechanical advantage for getting a better fit.

Users may have to augment the shoulder straps with Triglides for accessories requiring a horizontal attachment point instead of plastic loop.
Users may have to augment the shoulder straps with Tri-glides for accessories requiring a horizontal attachment point instead of plastic loop.

The shoulder pads are narrow but well padded, providing a comfortable fit for people with narrow shoulders. Both shoulder straps have load lifters, including front buckles for adjusting their angle when the shoulder harness is raised or lowered. The shoulder harness itself is minimal, and only touches the top of the wearer’s shoulders and back, good ventilation for keeping sweating at bay. External attachment options on the outside of the shoulder straps are somewhat limited however (a plastic loop is provided) and users may need to augment the straps with tri-glides in order to hang accessory pockets if a horizontal strap is required to connect them.


  • Hip belt is extremely comfortable and provides excellent load transfer because it is attached to the central aluminum stay
  • Front anchor of the load lifter straps is adjustable, ensuring the ability to keep load lifters at a 30-45 degree angle when the torso length of the pack is adjusted. This is a high-end feature, normally only found on expedition class backpacks.
  • Tapered main compartment and hip control straps helps ensure a very stable carry, despite the fact that the pack only has a single central frame stay.
  • Bottom compression straps can be threaded to run through inside of the side mesh pockets or outside, enabling compression when carrying water bottles, or external gear attachment (such as snowshoes).
  • Velcro webbing keepers help keep the numerous straps under reasonable control


  • No torso length information on the webbing strap which controls torso length, so users have to be fairly experienced to determine whether the torso length is adjusted correctly or not.
  • Hip belt runs a bit small for a size 38″ waist.
  • Top lid slumps back and off-center when the main compartment is not fully loaded. This is a common problem with alpine style packs with a floating lid.
  • No bottom reinforcement on side stretch mesh pockets making them more prone to tearing on vegetation.


The Exped Thunder 70 is an extremely comfortable and versatile high volume backpack that can be outfitted for many different types of adventures, ranging from backcountry trips to more urban front country adventures. Featuring convenient rear panel gear access, the Thunder is ideal for multi-sport trips that require different clothing or equipment at different times, such as climbing or mountaineering trips that require long approach hikes followed by sport-specific activities. Weighing just 3 pounds 6 ounces, the Thunder 70’s unique shoulder harness, hip belt and aluminum stay system provide exceptional load carrying capabilities for a backpack of its size. The Thunder 70’s hip belt is one of the best I’ve ever used and I’m difficult to impress.

Backpack Features

  • Made with 210 Dyneema Grid Check and Stretch Mesh
  • 70 liter capacity (covered storage)
  • Available in Men’s and Women’s models
  • Adjustable torso length
  • External stay
  • Two stretch mesh side water bottle pockets with pass-through compression webbing
  • Front stretch mesh pocket
  • Two front daisy chains
  • Floating lid with one external and one internal pocket
  • Top rope carrying strap
  • Spindrift collar
  • Hydration pocket
  • Dual ice axe loops with elastic shaft holders
  • Hip belt with scherer cinch and lumbar pad
  • Two stretch mesh hip belt pockets
  • Two tiers of compression straps
  • Load lifters with front angle adjustment
  • Adjustable sternum strap
  • Webbing cord keepers
  • Aluminum hooks instead of plastic buckle
  • Numerous external attachment points on pack body and lid

Disclosure: Exped donated a backpack for this review. 

SectionHiker is reader-supported. We only make money if you purchase a product through our affiliate links. Help us continue to test and write unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.


  1. Very nice review. How do you compare this with the UNAWEEP 4800 which you recently reviewed. I’d like to also know how these two packs compare with the SixMoonDesign Fusion 65 pack — all 3 of these packs are lightweight large packs, all interesting for doing a 28 day JMT hike (John Muir Trail).

    • I can’t speak to the Fusion 65 since I haven’t used it, but it’s obviously smaller than these two packs.

      The UNAWEEP 4800 (80 liter) is made out of a bombproof material (VX21 and VX42 Xpac) that is virtually indestructible which is good if you hike off trail or are really hard on your packs. (You could probably tie the thing to the back bumper of your truck and drag it down a dirt road and it would hold up fine.) It’s also capable of carrying very heavy loads in excess or 100 pounds, since it was originally designed as a game hauler for the hunting market. While it’s also good for backpacking, it’s not a pack that is going to have a lot of success in a retail setting because it’s so different from anything else.If anything, the Unaweep is the antithesis of an alpine sack like the Thunder 70, which has a more traditional backpack look and functions like a top loading pack. The Thunder 70 is also much more user friendly, in the sense that the components of the pack have obvious uses, while you need to use your imagintion more to use the Unaweep. I’d also never take the Thunder 70 off traill, because I’d rip up all the mesh on the pack in an afternoon.

      The interesting thing about both packs is that they both have external frames, although the Thunder isn’t as stiff as the Unaweep, and feels and functions much more like a conventional internal fame pack.

      I don’t know what you plan to do on your 28 day hike of the JMT or if you plan to resupply or not. But if you plan on beating the crap out of your pack and carrying a very heavy load, I’d go with the Unaweep. Otherwise, the Thunder 70 will hold up fine. But I also know people who do the JMT with a 46 liter Gossamer Gear Gorilla. Why do you need such a big pack?

  2. Phillip, any recommendations or data on maximum weight for this backpack? Based on the frame elements and size it appears the backpack would be reasonable for weights up into the 40# range?

  3. How can you compare Exped and Paradox belts?

  4. Many thanks for this detailed review!
    Would you say this backpack can be a good alternative to the most common ones used (e.g. ULA Catalyst) to thru-hike the PCT and/or Te Araroa in New Zealand with?

  5. How much does this hip belt move with the natural walking motion of your hips? I tried on an Arcteryx pack the other day and loved that the pack stayed stable while the hip belt gently rocked, not digging as I walked or stepped up. That said, I like the Exped Thunder’s styling, features, and price/value a lot more. The Velcro strips to wrap up extra webbing are a great idea, for example.

    • Not much. It’s not sewn on, but it’s still quite stable. Suggest you compare the two for yourself.

      • Thanks. Pulled the trigger on this when it went on sale at Moosejaw. Kept coming back to this as the best mix of load capacity (not sure how lightweight I’ll be able to do the Philmont trek next year), volume, weight, easy adjustability, and price.

    • Just finished a 65-mile trek at Philmont. The pack weight varied between 35 and the low 40s depending on the food resupply point and water needs, yet the Thunder always felt comfortable, with the weight carrying neatly through the hip belt. I lost a little weight by the end and had to readjust the shoulder strap height as the pack slipped a little down my hips. (Could have used an even smaller belt.) But that adjustment was easily done with this pack, compared to other people trying to readjust their Osprey packs, where the adjustment is buried behind the air suspension system. Only downside is that the pack looks sloppy with a partial load — as we had for a summit up Baldy — but that is the downside of any pack with an alpine-style lid. Side pockets worked fine for fuel bottles or an Evernew water pouch. Back mesh pocket is pretty tight with a full load, and a second Evernew water pouch was about all I could slip in there. Pack is a bit dingy after the trip but none the worse for wear.

  6. Nice review.

    I am curious. IS the 70L volume only the main bag and lid? In other words is the volume greater when the front mesh section and side pockets are included in the calculation? The reason I ask, is that I own the ULA Circuit and was seeking a larger bag for certain adventures. ULA lists the Circuit at 68L However, that includes ALL pockets. The main bag is only 39 L. It appears that the Thunder may have a greater capacity. I was considering the Catalyst until I stumbled on the Thunder 70.

    • You’d have to contact Exped and ask. I would expect them to abide by the standard and not count open storage, but don’t know for sure.

      • I have the Exped Thunder 70L, it is about a pound heavier than the ULA pack, but the main compartment is 70L. The small main pocket is why I avoided the ULA.

  7. Have you compare the Thundr with the nex Paragon 68 for winter hinking in the snow ?

  8. Hi Phil, How do you think the Exped Thunder 70 compares with the “newer” SD Flex Capacitor 60-75 for multi day trips year round?

  9. Good evening Phil,
    I myself am also considering the new Sierra Designs 60-75 liter and the Exped Thunder 70. Any thoughts on choosing between the 2. I tried SD’s 40-60, but unfortunately I don’t have has lightweight equipment as others might.
    Thanks for your time.

    • Hey Jan. I think the biggest difference is the access. Going through the top lid on the SD is kind of a pain in a really big pack. A side zipper is really useful in such circumstances. The Panel access of the Thunder was really designed with this use case in mind. But the SD pack is really good at carrying heavy gear.

      • Thank you for responding back so quickly. The side zipper would definitely make it more accessible, although I hardly access the bag till I’m at camp. Granted that’s when one accesses it, and peering into it with one’s headlamp is no fun. My Atmos 65 carries gear in the several pockets( and half the time I forget where I put it lol). Unfortunately that bag does not transfer the weight to the hips anywhere as well as the SD pack. My pack weight including water is for sure never more than 35 lbs probably closer to 30 lbs. my gear is just not that compact. For example I use Big Agnes Copper Spur UL2 tent and would like to be able to put it outside if I cannot fit it inside, but neither pack has an area similar to the Atmos for this.
        I was able to retrieve and put back the water bottles on the side pocket of the SD pack fairly easily. How stretchy/flexible are the Thunders as well as the large stash pocket. If the large stash pocket is similar to Granite Gear newest Crown 2 that might be a bit concerning. The Thunder appears to be less stiff in the suspension pads than the SD pack. Perhaps you could speak to that as well.
        Thanks again

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