Two backpacks worth lining up side by side. The Arc Zip Ultra 62 takes a modest overall edge, led by low weight, but the Unbound 55 has its own case.
| Zpacks Arc Zip Ultra 62 | Hyperlite Mountain Gear Unbound 55 | |
|---|---|---|
| GearScore | 72✓ | 68 |
| Capacity | 62 L | 55 L |
| Weight | 1 lb 9 oz✓ | 1 lb 13 oz |
| Rated load | 40 lb | 40 lb |
| Fabric denier | 100 D | n/s |
| Price | $449 | $420✓ |
| Type | Ultralight | Ultralight |
| Frame | Internal | Internal |
Highlighted cells mark the better spec: Arc Zip Ultra 62 in blue, Unbound 55 in amber. A blank spec is never counted as a win. Capacity is shown for context and is not scored, since more volume is a sizing choice rather than better. GearScore is the overall rating (0 to 100); re-weight it on the full backpack comparison. Prices are current MSRP.
The Zpacks Arc Zip Ultra 62 and Hyperlite Unbound 55 take different routes to the same job. The Arc Zip Ultra 62 wins on low weight, and the Unbound 55 pushes back on price.
The Arc Zip Ultra 62 is 4 oz lighter. The Unbound 55 is $29 cheaper. On the default GearScore the Arc Zip Ultra 62 leads 72 to 68.
Pick the Arc Zip Ultra 62 if you care most about low weight, which makes it the better call for counting grams on long miles. Pick the Unbound 55 if price matter more to you, or you are focused on getting the most for your money.
The Zpacks Arc Zip Ultra 62. It is 4 oz lighter than the Unbound 55.
The Hyperlite Unbound 55. It is $29 cheaper than the Arc Zip Ultra 62.
The Zpacks Arc Zip Ultra 62, 72 to 68 on the default algorithm. You can re-weight the factors to match your trip.
It depends on your priorities. Go with the Arc Zip Ultra 62 for low weight, or the Unbound 55 for price. The spec table above shows exactly where each wins.