I’ve had a few months to demo and review the Italian made AKU Hayatsuki Mountaineering Boots and I’m ready to share my opinion on them! Let’s get the disclaimer out of the way first. I first heard of this company through a social media ad and I purchased a pair of the AKU Rock DFS Approach Shoes because I have a thing for approach shoes! The shoes performed so well I published this review and later reached out to see if I could get a media sample of the AKU Hayatsuki Mountaineering Boots to review. AKU supplied me with a pair to check out but this has in no way effected my opinion of the boots. Read on to see how they were tested and how they performed!
How they were tested:
Test period: December – March
Use: Winter hiking, mountaineering, and waterfall ice climbing in the White Mountains of New Hampshire. Approx. 20 days of use, 100+ miles, over 40,000 feet of elevation gain/loss.
Bottom Line (TL;DR version)
These are a solid choice for the winter hiker/climber who spends equal time between general winter mountaineering (snow climbing) and more technical waterfall ice climbing that won’t break the bank!
The Details:
AKU Hayatsuki GTX Backpacking/Mountaineering Boots Review
Sizing/Fit/Comfort:
I went with a UK 8, EUR 42, USA M 8.5 and the fit was perfect for my medium width foot with a regular arch and a slight Morton’s toe. The lacing system has a great pulley system at the lower top of the foot, 6 “mini” pulley’s to be exact then a self-locking ratchet mechanism. This system makes securing the foot in the boot super quick and efficient. The result is zero toe-bashing while kicking up waterfall ice while wearing crampons or while descending of any steep hiking trail. I never felt a need to “snug up” my laces for the descent with these boots feeling comfortable and secure all day long!
Performance:
For general winter hiking and mountaineering these performed quite well! AKU doesn’t list how much Primaloft insulation is in the liner but there is enough to keep my feet toasty down to 10 degrees below Fahrenheit with wind chills around -20 to -30 above tree-line. My feet stayed warm throughout each trip (wearing my Darn Tough Mountaineering Socks)! For general winter hiking and mountaineering I paired them with my Petzl Vasak 12-Point Mountaineering Crampons and they worked great together!
AKU Hayatsuki Mountaineering Boots Review
For ice climbing I was quite impressed with their performance, especially at the price point! The lasting board, which gives the sole its stiffness, is made out of “6-4 MM Nylon & Die Cut EVA for Rock Protection & Stability”. More important to me is the welt is fully compatible with my technical ice climbing crampons with a solid front and back lip on the welt. My Petzl Dart Crampons fit perfectly on the welt and felt secure on many pitches of Grade 3 waterfall ice.
Summary
The AKU Hayatsuki Mountaineering Boots are a great winter “all-a-rounder” that will basically perform well in pretty much any snowy situation below 8000 feet. This makes them an excellent choice for winter hikers working on their “Winter 48” 4000 footer list, and for winter hikers who are considering breaking into the waterfall ice climbing sport. They are technical enough to handle waterfall ice and mixed climbing at almost half the price of most technical ice climbing specific boots. The fact that they are made in Italy is apparent in their craftsmanship and I have no doubt these boots can survive a decade of winter exploration. If you’re in the market for a great pair of winter hiking boots you should give these a try!
See you in the mountains,
Northeast Alpine Start
A media sample was provided for purpose of review. Affiliate links above support this blog. Thank you.
Likely one of the most important choices a climber makes involves their footwear. Happy feet are so crucial for happy climbing and my feet have been quite happy the last few winters while I’ve been testing the Arc’Teryx Acrux AR Mountaineering Boots. Before I break into the details here is how they have been tested:
Mountaineering: (paired with Petzl Vasak Leverlock crampons)
Two full winters guiding in the Northeast with 4 winter ascents of Mount Washington with the lowest ambient air temperature around -20f and wind-chills around -50f. Some alpine climbing in the Cascades with ascents of Mount Shuksan, Forbidden Peak, and Rainier.
The author on the summit of Mt. Rainier- Photo by @cfphotography
Waterfall Ice Climbing: (paired with Petzl Vasak Crampons, Black Diamond Cyborg’s, and CAMP/Cassin Blade Runner’s)
30+ pitches of waterfall ice climbing including Black Pudding Gully (WI4+), The Black Dike (WI4+) Drool of the Beast (WI5-) and Repentance (WI5).
The author on Black Pudding Gully (WI4+), photo by Brent Doscher
The author on Drool of the Beast, photo by Brent Doscher
The author enjoying some late season ice last March
Black Dike, Cannon Cliff, New Hampshire- photo by Peter Brandon
I mention specifically what crampons I tested these with as this is a very important consideration when selecting a climbing boot, especially in this case and I will get into that further in the review. But first lets take a look at some of the details of this design.
I’ll start with some preliminary info from when I first received these boots back in October 2016.
“A pinnacle of design for mountaineering, ice and mixed climbing, the Acrux AR is the lightest, most durable, and lowest profile insulated double boot available.”- Arcteryx.com
That is a strong statement, and it happens to be true. Let’s compare some of the other lightweight double boots on the market:
La Sportiva Spantik (88.96 oz/pair)
La Sportiva Baruntse (82.96 oz/pair)
La Sportiva G2 SM (72.22 oz/pair)
Scarpa Phantom 6000 (70 oz/pair)
Arc’teryx Acrux AR (69.1 oz/pair)
This is actually less than an ounce difference than my La Sportiva Batura 2.0’s that I reviewed last winter here.
The obvious difference between these and my Batura’s is that these have a removable liner.
These liners “feel high-tech” in hand. I wore them around the house and they feel like a comfy slipper designed for astronauts. From arcteryx.com:
“Arc’teryx Adaptive Fit technology uses a removable bootie that employs stretch textiles and minimal seams to create an instant custom fit with no pressure. With protection extended beyond the cuff of the boot and the highest level of breathability in this category, the bootie’s GORE-TEX® membrane optimizes climate control and waterproof benefit. The perforated PE foam’s quick dry properties improve comfort, and a rubberized sole allows the bootie to be used as a camp shoe.”
Arc’teryx partnered with Vibram® and created the AR outsole using Vibram® Mont rubber which keeps its frictional properties in sub-zero temps.
“The specially developed Vibram® AR outsole is designed for support and sure footedness. The tread and construction feature a semi-blocked toe, with anti-slip grooves, a medial climbing support zone, and heel created to provide braking on steep descents. The Vibram® Mont rubber compound maintains its performance in sub-zero conditions.”
Now that I have had sufficient time in the field to test them let’s get into the question on everyone’s mind. How do these perform?
On the approach
Honestly these have been the most comfortable mountaineering boots I have yet to wear. They feel like they were custom made for my feet. For reference I am a US men’s size 9, EUR 42, medium width forefoot with a slight Morton’s toe. Unlike my previous double boots (Koflach Degre, Vertical, and Arctis Expe) it is easier to put this boot on by first putting the slim fitting liner on then sliding into the outer boot. When the liner is already in the boot it is a little more tricky to slide on but not impossible.
The lacing system is probably the only thing I could imagine being improved upon. There is no traction/tension grabber that is becoming common in a lot of boots in this category. For a boot at the high end of the category I would LOVE to see Arcteryx take it a step further and add a ratcheting lacing system like Boa.
As it stands I’ve adapted my lacing strategy. For general mountaineering and easy ice climbing I lace them at home and leave them all day. For harder ice climbing (WI4 and up) I’ll lace them at home, approach, then take the time at the base of the route to snug them up for better performance on the vertical. It doesn’t take long and leaving them loosely laced on steep ice can lead to some insecurity.
For comfort on the approach and descent these score very high. They are super light and warm enough for my feet in all the conditions I’ve tested them in. I do have “warm” feet though so if you suffer from cold feet I would suggest some solid test runs before going to significant altitude. The long term comfort is so significant that I’ve returned home after 14 hour days and left them on while stocking the wood stove and cooking dinner. No joke I have not felt the need to pull my feet out of these as soon as I get home even after significant slogs.
One of the reasons they might be so comfortable on the approach and descent is the small amount of flexibility within the shank/out-sole, a trait some who have tried them are concerned about, but one that I feel is easily remedied. I will elaborate more on that in the next section.
On the climb
The slim looking low profile Arc’Teryx Acrux AR Mountaineering Boots are the Lamborghini of the climbing boot world. Ok, that might be going a bit overboard but seriously I find these perform extremely well on steep water ice when paired with the right crampon. Why is the crampon pairing so important? Two reasons.
These are super light boots. For hard ice climbs a heavier crampon might actually reduce your energy expenditure by giving your boot/crampon a better balance for efficient kicks. Before you call me crazy consider this is the same theory that explains the practice of adding pick weights to your ice axes. I find the heavier Black Diamond Cyborgs and CAMP Cassin Blade Runners to add a nice amount of weight allowing me to “kick lighter” and let the boot/crampon do the work. So super light boots are a plus for the approach and descent, but it’s nice to add a little mass for the kicking portion of your climb!
These boots have some flex. That small amount of forefoot flex feels great on that 8 mile approach, but when you are front-pointing on near vertical ice having a secure platform takes precedence. I noticed the flex first when leading a 3+ route wearing my well worn Petzl Vasak Crampons. It wasn’t a big deal, but it was noticeable. I’ve since lead multiple grade 5 ice routes using the Black Diamond Cyborgs and CAMP Cassin Blade Runners and in all cases the inclusion of the stiff heavier crampon virtually eliminated all noticeable flexibility while front-pointing on both steep rock and ice.
Five months of some of the best Northeastern ice climbing I’ve had in years have left me with a super positive impression of the Arc’Teryx Acrux AR Mountaineering Boots. Slipper like comfort, 3-season like weight (yet still plenty warm for my feet), and high end performance when it matters most all add up to a fantastic new edition to the growing assortment of lightweight double boots. You should try a pair on!
UPDATE (10/22/2018)
Two years later and I’m still in love with these boots! I climbed Mount Shuksan, Forbidden Peak, and Rainier in them the following summer! You can see those trip reports here.
Thanks for reading! Take it one step further and comment below! Have you tried them? What did you think? What’s your current boot crampon/setup?
Disclaimer: Arc’Teyrx provided a pair of these boots for the purposes of review but all opinions expressed above are my own. Affiliate links help support the content created at Northeast Alpine Start at no additional cost to you! Thank you!
While I am excited about all the products I’ll be testing this winter I am perhaps most stoked to put this duo together and get on some early season ice as soon as possible! I’m hoping I’ll get enough field days in to have a full review post for each by early-mid January. I realize though by then a lot of ice climbers may have already geared up and wanted to share my first impressions on these before the season arrives.
“A pinnacle of design for mountaineering, ice and mixed climbing, the Acrux AR is the lightest, most durable, and lowest profile insulated double boot available.”- Arcteryx.com
That is a strong statement, and it happens to be true. Let’s compare some of the other lightweight double boots on the market:
The obvious difference here between these and my Batura’s is that these have a removable liner.
ACRUX AR MOUNTAINEERING BOOT PREVIEW
ACRUX AR MOUNTAINEERING BOOT removable liner
These liners “feel high-tech” in hand. I wore them around the house and they feel like a comfy slipper designed for astronauts. From arcteryx.com:
“Arc’teryx Adaptive Fit technology uses a removable bootie that employs stretch textiles and minimal seams to create an instant custom fit with no pressure. With protection extended beyond the cuff of the boot and the highest level of breathability in this category, the bootie’s GORE-TEX® membrane optimizes climate control and waterproof benefit. The perforated PE foam’s quick dry properties improve comfort, and a rubberized sole allows the bootie to be used as a camp shoe.”
Arc’teryx partnered with Vibram® and created the AR outsole using Vibram® Mont rubber which keeps its frictional properties in sub-zero temps.
The Vibram® AR outersole uses Vibram® Mont rubber to perform well even in extreme cold
“The specially developed Vibram® AR outsole is designed for support and sure footedness. The tread and construction feature a semi-blocked toe, with anti-slip grooves, a medial climbing support zone, and heel created to provide braking on steep descents. The Vibram® Mont rubber compound maintains its performance in sub-zero conditions.”
I’ll share a promotional video on the boots and move onto the crampons I’ll be pairing with them this winter!
These are the most aggressive fully adaptable to any situation crampons I have seen. I used to love my older Petzl M10 crampons because I could swap out the front points for either dual, mono, or mono-offset. The Blade Runner’s do all that but CAMP also makes optional “snow points” so you can turn your vertical ice crampon into a multiple purpose mountaineering crampon. It really does make these incredibly versatile! My demo pair arrived set for offset mono and I plan to test them that way first with our thin early season ice conditions. Included with the crampons were two more vertical front points and semi-automatic toe bails allow for use on boots without rigid toe lugs.
Included extra parts
Fit
How well a crampon can attach to your boot is paramount. You want them to feel like they were designed for each other and no one else. Right out of the box the fit on the Acrteryx AR was quite good. There is plenty of adjust-ability to make it “perfect” starting with three possible toe bail positions, two possible heel lever bar positions, full vertical adjustment on the heel lever itself, and, something I haven’t seen before, the asymmetric bottom that more closely follows the contours of the boot outer-sole.
CAMP Cassin Blade Runner Crampons- a snug fit
Vertical heel lever adjustment
Obviously we can’t talk much about performance just yet but they are definitely a very aggressive crampon! One could argue this is a 19 point crampon (20 if set up in dual front-point mode). The design looks like it will excel on steep & cauliflower ice.
Cassin Blade Runner Crampons- aggressive, included anti-balling plates
The front points are made from Chromoly Steel and taper from 5mm down to 3mm. A “wear indicator” of sorts lets you know when it’s time to swap in new front points.
Think the Arcteryx Acrux AR boots might be good for you?
You can purchase them on Amazon here. Ordering through that link will help support this blog.
Stay tuned this winter for lots of gear reviews and giveaways! I’ll be raffling off brand new climbing harnesses, ice screws, carabiners, and more. Don’t miss a review or giveaway! Subscribe/Follow this blog at the top right so you get all the details!
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