Verdict from 10 experts and 73 user reviews

11 reasons to buy

  • The Arc'teryx Acrux AR was shockingly lightweight for a mountaineering boot, based on a large percentage of user and expert reviews.
  • This boot earned heaps of praises from dozens of mountaineers for its warming capability.
  • To a considerable number of wearers, the Acrux AR was a force of nature in terms of comfort.
  • Many owners found a genuinely water-tight boot in this mountaineering footwear.
  • A moderate percentage of owners happily commended the Arc'teryx Acrux AR for its foot-conforming removable bootie.
  • According to a handful of users, this boot provided a highly precise climbing performance.
  • Some purchasers greatly appreciated the boot’s slim, low-volume look.
  • The Acrux AR impressed a few owners with its quick-drying removable liner.
  • Despite its obviously slender build, the boot was applauded by a couple of wearers for its overall durability.
  • A tiny fraction of testers got a great sense of security with the Acrux AR’s supportive heel zone.
  • This mountaineering boot had ample flexibility in all the right places, according to a professional footwear critic.

4 reasons not to buy

  • Some reviewers found the Acrux AR difficult to put on, especially when inserting the removable liner into the inner shell (also called the outer boot).
  • The footwear’s hefty price tag dampened the enthusiasm of a small minority which includes an expert blogger.
  • A professional reviewer struggled with the boot’s lengthy break-in period.
  • The gear's ankle zone losing stiffness three months in disappointed a footwear tester.

Bottom line

Arc'teryx successfully combines extreme lightness, top-quality comfort, and excellent climbing performance in one tough-as-nails boot called the Acrux AR. And this is without mentioning its mighty defenses against water intrusion and impressive thermal insulation yet. It, however, is not without its fair share of missteps. Some criticized the boot for its ridiculous asking price, while others detested the cumbersome process by which it must be worn. Overall, if wearers could turn a blind eye to the Acrux AR’s shortcomings, they would surely be treated to a fine product that could be argued ahead of its class.

Good to know

  • The Arc’teryx Acrux AR is a high-cut mountaineering double boot. Its lightness is, in large part, attributed to its layered upper which is made up of lightweight foam enclosures and breathable liners. It has doubled-down water protection, thanks to the Gore-Tex membrane lining in both the removable inner bootie and built-in gaiter.
  • Craftily hidden by Arc’teryx engineers is the boot’s EVA midsole which provides stability and cushioning over technical terrain. It also has welts both at the rear and front ends which make the boot compatible with automatic (step-in) crampons.
  • On the traction front, the Acrux AR has a specially developed outsole called Vibram AR. It has treads and lugs that work together to provide support and improve the user’s overall climbing performance.

The Arc’teryx Acrux AR is a unisex footgear specifically designed for mountain climbers. It has a fairly true-to-size fit. It is offered in standard width and comes in a number of whole and half sizes. Based on Arc’teryx's size chart, women have to go one size down to get the correct Acrux AR size. Powered by Arc’teryx’s Adaptive Fit technology, the inner liner provides a sock-like fit by closely adapting to the user’s foot anatomy. It also has a padded interior with minimal seams for a snug and pressure-free fit. A secure lockdown, on the other hand, is granted by the inner shell’s closure system.

With the Vibram AR outsole, the Arc’teryx Acrux AR delivers traction over terrain mostly characterized by extreme ruggedness and steepness. It is based on Vibram's Mont compound which grants the boot a kind of grip that can perform even in freezing temperatures. Its surface is loaded with anti-slip patterns and lugs of different shapes and sizes. The semi-blocky lugs of the outsole are positioned at opposing angles for ascent, descent, and medial traversal support. Also, preceding the arch zone is the sole’s heel brake which gives extra stopping power during descents.

Unyielding to the stress between the weight of the wearer and the craggy, mountainous terrain is the boot’s midsole. Made of ethylene-vinyl acetate (EVA), this cushy platform is designed to give wearers stability and shock mitigation without compromising comfort. EVA also enables this midsole to withstand the biting cold.

The boot’s heel and toe counters (also known as welts) onto which the levers of automatic crampons latch are made of TPU or thermoplastic polyurethane. This material is known for its hardiness and level of resistance against abrasions, impacts, and weathering.

Contributing to the Arc’teryx Acrux AR’s cushioning and support is the carbon fiber insole. Its core is made of expanded polyurethane foam for thermal insulation.

The Acrux AR from Arc’teryx has a 4-millimeter, 3D-formed inner shell which is made of polyethylene (PE) foam—a material that provides not only ample cushioning, but also adequate internal insulation. It is perforated which means it has the ability to disperse heat and wick away sweat and moisture from the inside. Its closure system features synthetic laces and Velcro-like straps.

The removable liner is also made of PE foam. Also, the designers imbued it with Gore-Tex’s waterproof membrane with climate control capabilities. This proprietary waterproofing technology has its three layers bonded together for enhanced durability.

Walling off the elements is the built-in gaiter. Made of the same 3-layer Gore-Tex membrane found in the removable liner, this protective covering is waterproof and durable. A zipper implement and a rivet button make up its sealing mechanism. A heavy-duty film made of TPU is laminated onto the base of the gaiter for bump and abrasion protection. It has a thickness of 0.6 mm.

  • Gently surface-clean the Arc'teryx Acrux AR with water either by hand or by using a soft bristled brush. Leave it to dry. Drying the footwear via any kind of heat source is discouraged.
  • The “AR” in the boot’s name simply stands for All-Round.


How Arc'teryx Acrux AR ranks compared to all other shoes
Top 20% mountaineering boots
All mountaineering boots
Top 1% Arc'teryx mountaineering boots
All Arc'teryx mountaineering boots
Top 16% waterproof mountaineering boots
All waterproof mountaineering boots


The current trend of Arc'teryx Acrux AR.
Compare to another shoe:
Paul Ronto
Paul Ronto

Over the past 20 years, Paul has climbed, hiked, and ran all over the world. He has summited peaks throughout the Americas, trekked through Africa, and tested his endurance in 24-hour trail races as well as 6 marathons. On average, he runs 30-50 miles a week in the foothills of Northern Colorado. His research is regularly cited in The New York Times, Washington Post, National Geographic, etc. On top of this, Paul is leading the running shoe lab where he cuts shoes apart and analyses every detail of the shoes that you might buy.