Zpacks Arc Blast 55L ($375)

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1 lb. 4.3 oz.

Dyneema (3.1 oz/sqyd)

Incredibly lightweight and water resistant.

Not very durable and doesn’t carry loads as well as the other UL packs here.

At about half a pound less than the lightest backpack we tested the Zpacks Arc Blast takes the ultralight top spot. The 55-liter model we tried is a whopping 1 pound, 8 ounces with additional features like two pockets for your hip belt. For construction, the Arc Blast has a similar waterproof Dyneema construction similar to the Hyperlite above, however in a much more compact design (3.1 sqyd of oz in comparison to. southwest’s 5.0 1 oz/sqyd). This is the reason for the lower weight, however we have discovered that the Zpacks are less durable in rough use or off-trail scrambling (we suffered a minor puncture on the lower part of our pack when we set it on a difficult trail).

Its “Arc” of the brand name is derived from the backpack’s unique tensioning mechanism which pulls the middle part of your backpack away from the back allowing airflow and reducing the requirement for an additional foam backpanel. The ability to breathe is among Dyneema’s weaknesses, and this design is ideal for hikers who enjoy hot weather. When combined with carbon fiber frames this pack is an extremely solid structure that provides adequate support for loads of up to around 30 pounds. We don’t suggest carrying more than that, since the padding is very small (the Southwest and Circuit above are more suitable for thru-hikers with larger loads). Overall the Arc Blast may not be sturdy enough as well as comfortable enough to be used by everyday weekend backpackers, but if take care with it the Arc Blast is an excellent choice for those who are serious about their hikes as well as minimalists.