Gossamer Gear Gorilla 40 vs Six Moon Designs Fusion 55

Weight and specs compared for 2026 — and which one to choose.

Six Moon Designs Fusion 55 is the lighter option — 29 g lighter than the Gossamer Gear Gorilla 40 (4% less weight). If grams matter to you, that is the one to beat.

Spec	Gossamer Gear Gorilla 40	Six Moon Designs Fusion 55
Weight	651 g · 0.651 kg · 1.44 lb	622 g · 0.622 kg · 1.37 lb
Brand	Gossamer Gear	Six Moon Designs
Category	Backpack	Backpack

Gossamer Gear Gorilla 40

651 g

Lightweight 40L weekend pack with internal frame.

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Six Moon Designs Fusion 55

622 g

Ultralight 55L frameless Dyneema pack.

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Gossamer Gear Gorilla 40 vs Six Moon Designs Fusion 55: which should you buy?

If saving weight is your priority, the Six Moon Designs Fusion 55 wins — at 622 g it is 29 g (4%) lighter than the Gossamer Gear Gorilla 40 (651 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest backpack page, or browse the full gear weight database.

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