Osprey Antigravity 64 UNLTD Backpack review: innovative comfort from a premium pack

Osprey’s UNTLD Antigravity 64 litre backpack aims to offer unrivalled comfort and fit for the adventurous – but at a hefty price point

T3 Platinum Award
Osprey Antigravity 64 UNLTD Backpack
(Image credit: Sian Lewis)
T3 Verdict

Hey big spender – if you take your mountain and travel adventures seriously and want a great quality, durable and weatherproof pack that’ll do you proud in any conditions, Osprey’s new and limited-edition UNLTD Antigravity 64 litre backpack is as top-of-the-range as you’ll find on sale this summer. Lesser mortals can pick a cheaper model.

Reasons to buy
  • +

    Great quality

  • +

    Reliably waterproof

  • +

    Supportive, weight-reducing frame

  • +

    Comfortable back panel and hip belt

Reasons to avoid
  • -

    The exorbitant price point

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    May not suit curvier bodies

Launched in the UK in March 2022, the limited edition (ironically, given that the UNLTD in its name is short for 'unlimited') Osprey UNLTD Antigravity 64 litre backpack (£650) and its sister design, the Airscape 68 litre pack, are the brand’s new and top-of-the-range rucksacks designed to be ‘industry gamechangers’. “These are hands down the most advanced backpacking packs ever developed,” says Osprey of these two rucksacks, both of which are available for men and women. 

I tested out the female version of the Antigravity pack, which is designed to keep you comfortable over long distances thanks to a 3D-printed back panel, to see what the fuss is about – and to decide whether this innovative but expensive rucksack is up there with the best hiking backpacks. Here's my full Osprey Antigravity 64 UNLTD Backpack review.

Osprey Antigravity 64 UNLTD Backpack review: comfort and fit

Osprey Antigravity 64 UNLTD Backpack

(Image credit: Sian Lewis)
Antigravity 64 UNLTD Backpack review: Specs (female pack)

Capacity: 64 litres
Dimensions: 81cm (L) x 41cm (W) x 39cm (D)
Weight: 2.9kg
Main material: 210 denier high-tenacity nylon ripstop
Waterproofing: water-resistant, rain cover included
Gender: men’s and women’s versions available
Colour: blue/green

The UNTLD Antigravity comes in two sizes for women, XS-S and M-L. I’m 5’7 and a size 12 and tried out the M-L, which fit my back very well, with little adjustment needed for a comfortable fit. The shoulder pads are mesh-lined and feel light and supportive, but the hip belt stands out even more – it’s unusually wide and curved, hugging your hips and lower back like a second skin and noticeably taking weight off your shoulders. Both sets of straps can be adjusted with the pack on but are pretty close-fitting – if you’re curvy with wide hips, this design may not suit your body shape. 

Osprey Antigravity 64 UNLTD Backpack

(Image credit: Sian Lewis)

The back panel of the Antigravity pack has been 3D printed using polyurethane (PU), and also stood out on test – it’s springy, flexible and comfortable and allows your back to stay cool and sweat-free far better than most other packs I’ve tested in the past. Hiking for five hours straight in the Antigravity on a hot sunny day, I was less aware of the pack on my back than I’d usually be when carrying a trekking pack, and I didn’t end up with a sweaty patch on my back or any pressure or redness on my shoulders or hips. Great for tropical travels and for long hiking days in the harness. 

Osprey Antigravity 64 UNLTD Backpack review: performance

Osprey Antigravity 64 UNLTD Backpack

(Image credit: Sian Lewis)

No backpack is ever fully waterproof unless it’s a dry bag design, but Osprey’s Antigravity is definitely water-resistant – on test I found that rain beaded right off the surface, and the protected main zip further kept contents dry. If it really starts to pour down, there’s also a great rain cover hidden away in a pocket at the base of the bag, so you’re covered even if you do get caught in a downpour.

The many pockets are well thought-out – I liked the two side pockets on the front of the pack, ideal for stashing a map or wet clothing and the deep water bottle pockets, which hold bottles snugly and allow you to grab water on the go. There’s also a lightweight stuff sack included that you can pop over the backpack for protection if you want to use the Antigravity as a checked-in bag. Externally, there are straps for just about everything you could need to carry, from a sleeping bag to ice axes or skis, and inside, a compression compartment helps store your sleeping bag snugly, and there’s room for a water reservoir in the top of the pack. 

Osprey Antigravity 64 UNLTD Backpack

(Image credit: Sian Lewis)

I liked the removable top pocket (or ‘top lid lumbar pack’, to give it its proper title), which can be worn across the body or as a bum bag – ideal for backpacking adventures or city weekenders. The Antigravity has clearly been carefully designed to work for all kinds of outdoorsy pursuits – and I’d definitely recommend it if you get up to all kinds of sports, hikes and adventures and want one pack you can grab again and again.

The Antigravity sits at the middling-to-larger end of the trekking backpack scale, holding 64 litres, and inside, there’s plenty of room for lightweight camping kit, clothing or sports kit such as a climbing rope. Side straps help compress the load, too. The Antigravity, despite its name, isn’t that lightweight at almost 3kg – about average for a pack of this size.

Osprey Antigravity 64 UNLTD Backpack review: alternatives to consider

If you don’t have over £600 to splash on a backpack but still want a good quality design, we rate Osprey’s more affordable Atmos 65 litre pack (opens in new tab) (for men) and Aura (opens in new tab) (for women), which cost around £220. On even more of a budget? The unisex OEX Vallo (opens in new tab) is a functional but spacious pick at £55.

Osprey Antigravity 64 UNLTD Backpack review: verdict

Osprey Antigravity 64 UNLTD Backpack

(Image credit: Sian Lewis)

Is Osprey’s Antigravity backpack (opens in new tab) an industry game-changer? I’m not sure. And is it worth more than double the price tag of other decent trekking backpacks on the market (including those from Osprey’s own highly-rated range)? Possibly not. What’s definitely true is that this pack offers excellent fit, quality and performance thanks to good weatherproofing, well-designed straps and an innovative back panel. 

If you’re keen to invest in a rucksack with tip-top performance, and then use it on frequent adventures or on your next long-distance hiking expedition, the Antigravity will definitely go the distance with you. 

Sian Lewis is an award-winning travel and outdoors writer, author and influencer. She's the author of popular blog and book The Girl Outdoors, and when

she isn't writing or travelling she spends most of her time hiking, cycling and wild swimming across Britain, testing out the latest adventure gear and clothing as she goes.