Arc Blast 55L Backpack

64
$325.00 Weight 20.2 oz / 573.0 g
Lead Time Ships in 2 weeks

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 and put you well on your way to that elusive sub-10 lb base weight.

 

  • 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.

Customer Reviews

5.0 Based on 64 Reviews
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SB
08/23/2019
Stephen B.
United States

Nice pack but took over three weeks to arrive even with expedited shipping.

Item took a very long time to arrive even with expedited shipping which I paid extra for.

SP
08/15/2019
Scott P.
United States United States

Great Fitting Pack!

Yet to take it on the trail, but did the body fitting, packed it with 5 days of gear and food and it fits so much better than my other ultralight pack. AND the 'pods' from the other pack fit perfectly. Will be out on the trail in September.

Scott P. verified customer review of Arc Blast 55L Backpack
TL
08/03/2019
TJ L.
United States United States

Best all around pack!

I just made the switch to UL gear. This pack came highly recommend by my friend Benny. This has been an amazing pack! When I’m not using it on a through hike I use it on all of my day hikes. The arc design keeps perfect airflow to keep you cool during any hike! Plus the adjustments this pack has truly allows you to customize the fit.

TJ L. verified customer review of Arc Blast 55L Backpack
JF
07/31/2019
James F.
United States United States

Love the bag

Was made faster than advertised and has exceeded all expectations. Have used the bag twice now for 20+ mile days and have had no back pain or hip issues which has always been an issue for me. 100% recommend if you are looking for a super simple effective bag.

TL
07/26/2019
TJ L.
United States United States

Simply Amazing

By far the best pack I have ever used. The adjustability of the Arc Blast allows you to place the pack where it is the most comfortable. The ability to upgrade with options is also a plus for truly being able to customize it to fit your needs. It is very durable and so light you can utilize it as a day pack when you are not using it on long hikes. I’m excited to have this pack for many years!