Arc Blast 55L Backpack

80 Reviews
$325.00 Weight 20.1 oz / 569.0 g
Lead Time Ships in 1 to 3 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 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 80 Reviews
5 ★
98% 
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4 ★
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MH
11/14/2019
Mark H.
United States United States

Better than I hoped for.

Transfers weight to my hips better than any pack I’ve ever tried. The fact that it’s lighter than most other packs is just a wonderful bonus.

RV
10/22/2019
Rob V.
United States United States

Exchange of Hip Belt for Arc Blast

Excellent customer service from Patrick of Zpacks! Replacement hip belt shipped out expeditiously. Will definitely purchase additional products and recommend Zpacks to my hiking friends. Topnotch quality and after-sale service!

SR
10/12/2019
Suzanne R.
United States United States

Soooo good

Absolutely LOVE this pack! Only wish I’d bought it sooner.... Excellent customer service and quicker delivery than expected. Also love being able to customize it.

TB
10/11/2019
Thomas B.
United States United States

Arc Blast a real Blast

Not since the original Kelty has a pack changed my experience on and off the trail. The Zpacks Arc Blast rides so well I sometimes have to check that I’ve got it on. The perfect UL backpack.

JG
10/04/2019
John G.
United States United States

Best pack ever

Up until last year I was sporting an external frame old school pack. Swore by it, its versatility. The only way I said I would ever get a new pack is if they re-engineered the old school external frame. Zpacks made it better. It weighs less than a soda bottle of 20 oz. Totally versatile easy-to-use I'm very comfortable. Thanks for the redesign on Old School pack