Arc Blast 55L Backpack

58
$325.00 Weight 20.2 oz / 573.0 g
Lead Time Ships in 7-10 Days

If you want to feel freedom of traveling along dusty trails and enjoy views from exposed ridge-lines, the Arc Blast is the ultralight backpack for you. This pack has our signature feature - the patented 'Flexed Arc' adjustable frame. This frame creates an air gap between your back and the pack, keeping you cool and providing a super comfortable fit. This fine-tuned innovative design makes the pack a true thru-hiker favorite.

Designed to accommodate a wide variety of modular add-ons, the Arc Blast allows you to dial in your perfect set up.

 

  • Constructed from 2.92 oz/sqyd DCF Hybrid. 

  • Roll top closure (like our dry bags) keeps water out, and lets you roll down the top as your gear load shrinks. All seams and attachment points are taped, making the pack highly water resistant. We still suggest using dry bags for your important items like your sleeping bag.

  • Comfy 3/8" thick by 2.5" wide padded contoured shoulder straps and padded belt. Both the straps and the belt have a daisy chain for clipping on items, and an adjustable position sternum strap is also included. The belt and shoulder straps have 3D mesh on the underside. This gives them a little bit more cushion, and the belt also has more texture for better grip.

  • Side pockets are sized to fit 1 or 1.5 liter bottles. They are positioned low on the pack and slanted forward for easy access without removing the pack. The pockets have drainage holes at the bottom, and elastic that keeps them tight at the top.
  • Large stretchy mesh center pocket is great for quick access items. Mesh also lets you dry wet clothing and gives you a clear view of your gear.

  • Side compression straps are made from non-stretchy Dyneema cord for squishing down the pack volume. They also allow you to stand tall items like trekking poles in the side pockets.

  • A top strap, and base straps allow you to lash on extra items to the top or base of the pack. The straps come off if you don't need them.

  • A centrally located Hydration Port is included to string out a drinking tube over either the left or right shoulder. It is just above/between the shoulder straps and it has a triangular cover to keep out water. A water bladder can either be hung from an internal hang loop or laid horizontally on top of your gear.

  • The 55L pack size has enough space for 5-6 days of food and ultralight gear. The pack can be compressed down with the roll top and side compression straps for short trips or use the top strap and base straps to lash extra stuff to the outside for long carries.

  • All standard Bear Canisters, including the Bearikade Expedition and the BearVault 500 will fit in the upper half of this pack standing on end. There is enough extra girth to either wrap a foam pad around the canister (if you use one) or stand a medium stuff sack vertically beside the bear canister.

  • The short and medium size frames will fit into an airplane overhead bin with the top rolled down to the frame. The tall size frame may not fit unless you pop the vertical frame bars out of the pack.

  • Our Flexed Arc Frame is is covered by US Patent No. 9,060,590

  • Our torso height adjustment mechanism is is covered by US Patent No. 9,848,687

  • All Zpacks gear has a two year limited warranty against defects in materials or workmanship. Please see our return / warranty policy.

  • Made in the USA.
  • Our ultralight Flexed Arc frame keeps the pack stiff so that most weight is carried on the hips instead of the shoulders. The frame pieces and mesh back panel can be easily removed or replaced.

  • The frame is curved to allow air flow and keep your back cushioned from the pack's contents. You can adjust the curve by tensioning the mesh back panel. The recommended arch is about 2.5" (6 cm).

  • The belt is attached directly to the bottom of the pack frame for the best load transfer.

  • The belt is removable and interchangeable. If you lose weight or need to share the pack between people, the belt can be swapped out. Watch the belt removal video.

  • The shoulder straps and load lifter straps are attached directly to the frame. Load lifters straps come standard on this pack.

  • The shoulder straps can move up or down to adjust the torso height to a perfect fit using our patented torso adjustment mechanism. It works like a conveyor belt. This is great for sharing the pack between people, for growing teenagers, or for resale.

  • The belt provides a full wrap around your back. No need for additional lumbar support.

  • The belt is done with "V-Style" webbing so that the top and bottom circumference can be adjusted independently. This helps wrap your hips much more securely and prevents the belt from sliding down.

  • Collectively, these features provide the additional load transfer necessary for loads up to around 35 lbs (16 kg).

Specifications:

Body dimensions: 7" x 12.5" x 30"  (18 cm x 31.8 cm x 76 cm)

Volume: 55L (42L main body, 2.5L each side pocket, 8L center pocket)

Frame Height: Short 19" (48.3 cm), Medium 21.5" (54.6 cm), Tall 24" (61 cm)

2.92 oz/sqyd Dyneema Composite Fabric Hybrid


Dyneema Composite Fabric is composed of high strength Dyneema fiber laminated inside a polyester membrane. It is inherently waterproof and does not require any coatings or DWR treatment. Dyneema Composite Fabric has very high tensile strength for its weight and does not stretch.

This hybrid version is made from 1.43 oz/sqyd Dyneema Composite Fabric on the inside, with an extra layer of protective 50 denier polyester on the outside. The outer layer gives it more strength and abrasion resistance, prevents fraying, and gives it a nice solid color. 

Tensile Strength:
 245 lb/in (2150 N/5cm)

Puncture Strength: 
7.3 lb (32 N)

Water Resistance:
 >20,000 mmH₂O

Made in the USA.



.3.5 oz/sqyd Mesh

This is the mesh that we use on our backpack's center pockets. It has a relatively light weight for mesh, while being difficult to tear. It can withstand getting caught on branches and other typical abrasion that backpacks are subjected to. The hole size is a about 4 mm (a little over 1/8"). 


Weight:
 3.5 oz/sqyd (119 g/m²)




5.3 oz/sqyd 3D Spacer Mesh

This mesh has a three-dimensional structure which allows airflow and adds cushioning. It has a tricot backing so you can't see clear through the holes. We use it on the underside of our backpack's shoulder straps and belts to absorb sweat, add cushion, and add grip. Our 3D mesh weighs less than most other types.


Weight:
 5.3 oz/sqyd (180 g/m²)

Thickness:
 About 3/32" (2.5 mm)


Torso Height:

To measure your torso height, you will need the help of a friend and a string or cloth tape measure.

Most hikers wear their belt near the top of their hips, however, it isn’t uncommon for hikers to position their belt higher or lower.

To ensure you lock in the perfect fit, we suggest putting a belt on over your clothes in the spot where you’d like to belt to ride. Start your measurement at the center of the belt where it meets your spine.

Lower your chin towards your chest.  This will cause the C7 vertebrae to protrude at the base of your neck. The C7 vertebrae will mark the top of your torso height measurement.

Using the string or cloth tape measure, follow the curve of your spine up from the center of your belt to your C7 vertebrae.  This measurement is your torso height.

Belt Size:

To measure your belt size, pull a string or cloth tape measure tight around the spot you’d like your belt to ride. Choose a belt with a minimum adjustment of a couple inches smaller than your actual waist measurement. This will leave room for you to tighten down the belt if you lose a little weight on trail.

The belts on our Arc Series packs are also removable and interchangeable. This will give you the ability to switch the belt out if your waist size changes.

The belt on this pack is removable and interchangeable. It can be swapped out.

To measure your torso height, you will need the help of a friend and a string or cloth tape measure.

Most hikers wear their belt near the top of their hips, however, it isn’t uncommon for hikers to position their belt higher or lower.

To ensure you lock in the perfect fit, we suggest putting a belt on over your clothes in the spot where you’d like to belt to ride. Start your measurement at the center of the belt where it meets your spine.

Lower your chin towards your chest.  This will cause the C7 vertebrae to protrude at the base of your neck. The C7 vertebrae will mark the top of your torso height measurement.

Using the string or cloth tape measure, follow the curve of your spine up from the center of your belt to your C7 vertebrae.  This measurement is your torso height.

Belt Size:

To measure your belt size, pull a string or cloth tape measure tight around the spot you’d like your belt to ride. Choose a belt with a minimum adjustment of a couple inches smaller than your actual waist measurement. This will leave room for you to tighten down the belt if you lose a little weight on trail.

The belts on our Arc Series packs are also removable and interchangeable. This will give you the ability to switch the belt out if your waist size changes.

The belt on this pack is removable and interchangeable. It can be swapped out.

Customer Reviews

5.0 Based on 58 Reviews
5 ★
98% 
57
4 ★
2% 
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06/20/2019
Anthony Smith

Top marks when I used for Coast to Coast

I used this backpack on the C2C in the UK. It rained almost everyday and the pack was watertight. On the top of Kitts Pike ( in the lake district) 4000ft, 40mph driving rain it didn't let in a drop. The fact that it didn't need a extra waterproof cover meant not having to worry that the cover might blow away. After 10 days days of constant use, no visible signs of wear or tear. Whilst not cheap, highly recommended. Easy to adjust. Small issue with the chest strap coming undone, but it easy easily fixed. Also used the trekking poles add on and that was worth the money as well.

SM
06/13/2019
Steven M.
United States United States

Longer wait than expected, but worth it.

I ordered two weeks ahead of a planned multi-day backpacking trip and paid for express shipping. Unfortunately, the pack did not arrive in time — manufacture took longer that what is posted on the website. So, I haven’t had a chance to use it on a longer hike, but I really like it. It weights almost nothing, but has lots of wonderful adjustments — be sure to check for video’s on the internet on how to properly fit the pack — and the frame nicely transfers the weight to my hips. One thing — it’s rainproof but not actually waterproof as the hydration port opens to the outside and would let in lots of water if suddenly submerged. I wish it had a few more external pockets, but there are lots of accessories that work in that regard. Overall very happy!

KS
06/12/2019
Keit Selbo

Fantastic, the most comfortable I've ever owned. There is however, a cost for the light weight.

I heartily recommend this pack without hesitation to anyone who can afford it. But as the title says, you can't have a light pack and expect durability in the same package. If it was, this would be a five, maybe six star review. I bought my first Arc Blast around 2013 to carry for the last four hundred miles of the Appalachian Trail. My wife came out to hike the Hundred Mile Wilderness with me. A day or two in, she was having trouble keeping up so I donned her 65 L Deuter and she took the Arc Blast. She never gave it back. I bought another one tricked out with most of the options available back then and have put probably fifteen hundred miles on it since. I went back to my Osprey Exos, which I had worn for about 600 miles on the AT, and took it for a 40 mile hike on the Tuscarora Trail. I regretted it. The Arc Blast has been my go to pack ever since. I don't know why it's so much more comfortable than my other packs; it just is. It transfers virtually all the weight to my hips and sits on them comfortably; no sore spots; no achy shoulders. It held my giant 24 in. Bearikade food canister and all my (minimalist ultralight) gear on my five day, 105 mi. Shenandoah National Park AT backpack. So what about the durability? You'll quickly learn not to throw it down on rocks, concrete or gravel like one usually does without thinking with cordura or other heavy materials. When I set it down, I look for grass or loam. Even so, I get all kinds of little dings and cuts that I never got on heavy packs. Zpacks doesn't lie about this so I was forewarned and have a length of cuben fiber repair tape at the ready so the cuts won't have a chance to grow. I've had a couple of holes form in the netting sack too. I made a temporary repair with duct tape, and mended them with hot glue when I got home. The hardware has also had it's problems. One day on the PCT in the middle of nowhere I tightened the belt only to have the buckle break. I knotted the belt together -- not convenient!-- until I got to a Wal-mart of all places to replace it. The little buckles that hold the trampoline netting to the frame have failed on both my, and my wife's packs. This is a bigger problem because they're sewn to their strap, making non-professional replacement difficult, if not impossible. It took me years to figure out how to effect a repair that still allowed me to adjust the net tension. I'm letting Zpacks know about it. If they like it, they can tell other owners how it's done. Lastly, one of the staves wore through one of it's mounts. I reinforced that mount and the other mounting points with pieces of metal cut from a soup can. No problems since. The Zpacks customer service through all this has been great. When I complained that the bed roll ribbons weren't reliable, Joel upgraded the pack to the newer cords. When the pack was returned to me, all the little holes had were patched and sewn. When I realized my pad/hammock roll was larger than most, Joel again happily supplied longer cord. So that's it; warts and all! I recommend this pack to anyone who doesn't mind dealing with the durability issues, which, in my opinion is worth it for the most comfortable pack I've ever owned.

AL
05/21/2019
Alison L.
United States

Just wow.

Haven't used it yet on the trail, but I can tell that the arc suspension and the rest of your amazing engineering has solved my most pressing ultralight backpacking issue--how to transfer weight to my hips instead of my injured shoulder. I'm so impressed, and will let you know how the first trek goes.

D
05/11/2019
David

Blew and blows my mind

The most intelligent, practical, effective, wonderful, utilitarian, wonderfully adjustable, conformable, and COMFORTABLE pack I have ever owned - far better than anything I could have ever dreamed up. I'm 62 years old and have been backpacking all my life, around the world, and this pack beats any other bag I have ever seen, tried, or owned. And it is amazingly light. I waited until I logged at least 10 days backpacking with it to write my review, but now it's time and this bag deserves every word above and every accolade on this site. It is almost too good to be true. I'm looking forward to putting it through it's paces this summer!! Thank you Zpacks!!!! David