Zpacks Arc Pro

The Zpacks Arc Pro is an ultralight backpack that takes standard pack designs and introduces unique features for comfort and usability. I tested the size medium 60 L Arc Pro on a trip in the Canadian Rockies where I pushed the advertised comfortable weight carry limit of 15.9 kg (35 lb). On my scale, the pack weighs 624 g (1.4 lb) without hipbelt pockets and 705 g (1.6 lb) with hipbelt pockets.

For comfort, the Arc pro has a full frame, load lifters, and hipbelt. What makes the pack unique is that, in addition to coming in three torso sizes, it comes with adjustable shoulder straps that allow for fine tuning the torso length fit by 5.1 cm (2 in) to 7.6 cm (3 in). There are also two load lifter connection points at the top of the frame so that you can optimize the load lifter strap angle. I started with the pack on the lower attachment point and noticed a big difference in comfort when I moved the load lifters to the upper attachment points. The load lifters and frame do a good job transferring weight to the hipbelt but the hipbelt is the weak point for carrying comfort. I tested the Arc Pro with 15.9 kg (35 lb) of gear in the pack and, with the adjustable aspects dialed in, felt like that was the most I could carry comfortably. The thin and soft foam of the hipbelt starts to be overwhelmed by the weight in the pack at 15.9 kg (35 lb) and that uncomfortably shifts weight to the lower back. Stiffer foam in the hipbelt would improve carrying comfort for heavier weights, but would also make the pack heavier. In the current design, I think the Arc Pro is an excellent balance of weight and carrying comfort.

The Zpacks Arc Pro is designed for access to items so that you do not need to stop while accessing water, snacks, or other gear. I was able to reach back and remove a taller water bottle (like a SmartWater bottle) from the stretchy Venom Stretch Mesh side pockets but shorter bottles were difficult to remove due to the tall cut of the pockets. I think Zpacks could cut the pockets lower to make accessing water bottles easy. Because the side pockets are stretchy, I don’t think this would lead to water bottles falling out of the pockets more. The bottom pocket is a great location for storing snacks for a day of backpacking. The bottom pocket has a large opening on the right side for accessing the pocket. I think the large opening could be pleated or tightened to prevent items from falling out when the pack is not fully loaded. I would also like to see a garbage port added to the bottom pocket. Hipbelt pockets and shoulder strap pockets can be purchased separately, if needed.

The Arc Pro features a lot of modularity. The hipbelt, foam back panel, and frame can all be removed to lighten the pack. The S-shaped standard shoulder straps can also be switched for vest-style shoulder straps. The vest-style does add weight, weighing 196 g (6.9 oz) while the S-shaped shoulder straps weigh 81 g (2.8 oz). The modularity makes the Arc Pro a very versatile pack that accommodates a variety of backpacking styles.

Overall, the Zpacks Arc Pro is one of the lightest full-featured packs. With several tweaks, it could be the best ultralight pack available – an excellent choice for thru-hikers or people prioritizing weight.