Two backpacks worth lining up side by side. They score within a hair of each other, so it comes down to the details below.
| Kelty Zyp 48 | Granite Gear Perimeter 50 | |
|---|---|---|
| GearScore | 66✓ | 65 |
| Capacity | 48 L | 50 L |
| Weight | 3 lb 5 oz | 3 lb 2 oz✓ |
| Rated load | 40 lb | 40 lb |
| Fabric denier | 210 D✓ | 100 D |
| Price | $99.95✓ | $250 |
| Type | Backpacking | Backpacking |
| Frame | Internal | Internal |
Highlighted cells mark the better spec: Zyp 48 in blue, Perimeter 50 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 Kelty Zyp 48 and Granite Gear Perimeter 50 take different routes to the same job. They are close enough that this really is about which handful of specs you weight most.
The Zyp 48 is tougher fabric (210D vs 100D) and $150 cheaper. The Perimeter 50 is 3 oz lighter. Their GearScores land within a couple of points (66 vs 65), so neither runs away with it.
Pick the Zyp 48 if you care most about durability and price, which makes it the better call for rough ground and hard use. Pick the Perimeter 50 if low weight matter more to you, or you are focused on counting grams on long miles.
The Granite Gear Perimeter 50. It is 3 oz lighter than the Zyp 48.
The Kelty Zyp 48. It is tougher fabric (210D vs 100D) than the Perimeter 50.
They are nearly tied at 66 and 65 on the default algorithm, so re-weight the score to your own priorities to break the tie.
It depends on your priorities. Go with the Zyp 48 for durability, or the Perimeter 50 for low weight. The spec table above shows exactly where each wins.