Best Backcountry Ski Boots of 2020
Best Overall Backcountry Ski Boots
Tecnica Zero G Tour Pro
Our now-perennial Editors' Choice winner enters the fray from long-time alpine boot manufacturer Tecnica. Their previous touring boots were basically alpine boots with tech fittings and a walk mode. The Zero G Tour Pro, though, is a full, ground-up touring boot, and is remarkable in many ways. Essentially, these are "normal" ski boots that tour. The overall configuration is familiar and durable. The execution is light and well balanced for all-around, high downhill energy backcountry skiing. The weight-to-downhill performance ratio is amazing. This Tecnica is lighter than many options of just a few years ago and skis downhill better than most AT boots available at any weight. Further, the cuff range and low-friction enable near-effortless touring and walking. You immediately trust these boots for their familiarity, and the performance won't let you down.
All AT boots present inherent trade-offs. Right off the bat, uphill and downhill performance are inherently conflicting. Boots get better and better at optimizing both, but you can't have it all. There are definitely other boots that tour better than the Tecnica, and there are a few that ski downhill better. Further, to minimize weight and maximize performance (uphill and down), warmth is sacrificed; the G Tour Pro is noticeably less insulating than average touring boots.
Read review: Tecnica Zero G Tour Pro
Best Bang for the Buck - All-Around Backcountry Skiing
La Sportiva Spectre 2.0
Of the twelve boots we tested, the La Sportiva Spectre 2.0 is the least expensive. With most contemporary AT boots performing well, our discerning initial selection criteria, and with the available magic of professional boot fitting, value hunting is simply a matter of finding the cheapest thing in our list. The Spectre 2.0 has been on the market for years now, with past versions often deeply discounted. They are light, tour well, and ski well enough for casual backcountry skiing. Get excellent help in fitting them to your feet, and you will be well served for a long time.
When they debuted years ago, the La Sportiva Spectre was the "world's lightest four buckle backcountry ski boot", and the benefits of low weight are obvious. The "four buckle" qualifier is a sort of proxy for downhill performance. More buckles equals greater performance, to some degree. However, this claim has since been surpassed and some products have gotten much better and lighter. Four buckle boots are now even lighter (see the Editors' Choice Tecnica) and boots with fewer buckles ski really well (see the Dynafit Hoji and the Scarpa Maestrale RS.) In any case, the Spectre is a little out of date. Others ski and tour better and are lighter. At the price, though, you shouldn't be disappointed with the performance of the Spectre 2.0.
Read review: La Sportiva Spectre 2.0
Best Bang for the Buck- Fast and Light Ski Touring and Ski Mountaineering
Atomic Backland Carbon
You want a second, lighter ski touring setup. Or you know, right off the bat, that you will prefer lighter weight ski gear. But you are on a budget. In this niche, the Atomic Backland Carbon is the best boot we have assessed. It uses proven technology and brings ultralight performance to a price point a few hundred dollars below that of close competitors. This thing is comfy and tours uphill like a dream. Pair it with similarly lightweight skis and bindings and you will fly up entire mountains, fresh and ready for huge downhills.
You'll pay a bit of a price on those downhills. The lower cuff and softer flex of these lightweight boots will never ski downhill like beefier boots will. We are confident that you will be more than willing to accept this compromise. However, you need to fully understand what you are getting into. These are suitable for expert level skiers, on small skis, that are willing to tone down the energy in their downhill skiing in exchange for uphill efficiency. Further, the fit of the Atomic Backland is relatively high volume. For optimum downhill performance in any sort of boot like this a close fit is best. These will perform best for those with wider or higher volume feet.
Read review: Atomic Backland Carbon
Best AT Boot for Ski Mountaineering and High-Speed Touring
Scarpa Alien RS
For huge days and ski mountaineering objectives, the Scarpa Alien RS is a slipper among backcountry ski boots. It feels improbably light and nimble, with more range of motion than most folks have flexibility for. The cuff of the Alien hinges more than your ankle can! As compared to even its closest competitors, the Alien is lighter, with better downhill performance and incredible transition and uphill efficiency.
For these reasons, it steps away from its close competitor when the objectives are more in the ski mountaineering realm. The transition requirements of the Alien RS are by far the easiest of any boot we tested. Any transition, whether from ski to tour or vice versa, doesn't require lifting your pant cuff. For specialized and high-speed missions, the Scarpa Alien RS is just right. For higher energy downhill skiing, other choices are better. For super cold conditions, look elsewhere, as the thin construction doesn't insulate well. We very much appreciate that Scarpa employs Intuition brand foam in their liners, but the Alien RS has the thinnest possible version of that brand's proprietary liners. Finally, be aware of the durability concerns associated with any sort of lightweight gear. To trim the ounces, the Alien RS uses light parts and thin cords and cables. We've had the sorts of failures you might expect in our full two years of testing all around the world.
Read review: Scarpa Alien RS
Best for Hard Charging Downhill Performance
Lange XT Freetour 130
The Lange XT FreeTour 130 is our Top Pick for best downhill-optimized AT boot. For someone who spends most of their time riding chairs or other mechanized access, it is a more comfortable boot for short tours, boot packs, and sidecountry touring. It is one of a few boots available that will work with tech style touring bindings AND with resort alpine bindings (the resort bindings must be "GripWalk" compatible). Even human-powered users should consider Lange. Our lead test editor and full-time backcountry ski guide one season used them for day-to-day guiding, where comfort, downhill performance, and warmth have great value.
The weight and lack of touring mobility will narrow the appeal of these boots. They don't tour nearly as well as any other option we assess.
Read review: Lange XT FreeTour 130
Why You Should Trust Us
Our AT ski boot testing team is led by long time tester and all-around mountain athlete
Jed Porter. As an IFMGA certified guide, Jed spends a huge amount of time on skis for both work and play. Furthermore, these professional and personal ski pursuits take him deep into the backcountry in a multitude of locales, providing a unique opportunity to put gear to the test over a variety of real-world conditions. In addition to Jed's wealth of knowledge and experience, we sought out input from seasoned ski mountaineers, beginner ski tourers and other guides to round out our evaluation of these ski boots.
We used our quiver of backcountry ski boots in locations all over the world. From the western United States to Canada, Alaska, Peru, Argentina, Chile, and Europe, our testers encountered every type of snow and terrain conditions. We took these boots up just as much as down and found whatever limitations, quirks, or impressive qualities each pair brought to the table. In addition to testing out in the wild, we measured, weighed, and flexed each boot in our lab to gain empirical data and see how manufacturer claims held up to our measurements.
Our backcountry ski boot test team has had hours of conversations with people, just like you, seeking advice, assessment, and comparisons between the ever-expanding list of options on the market. It is thoroughly mystifying, even if you are well-versed. We've got your back. With many decades of experience backcountry skiing, dozens of years spent in ski gear consulting, and thousands of days of touring, ski mountaineering, and human-powered ski guiding under the belt of our test team, we can make authoritative and relatable recommendations. We've distilled deep and broad information, critiquing hundreds, using dozens, and publishing here reviews on the twelve best backcountry ski boots on the market.
Related: How We Tested Backcountry Ski Boots
Analysis and Test Results
We tested all of these boots over the past couple years and garnered a wide range of feedback from outdoor professionals, local ski shops, mountain guides, patrollers, ski instructors and more. We compared them both side-by-side as well as individually out in the field while using them. We use them how we expect you'd use them and reported our findings below. We compared and scored them in six categories. Our focus is on human-powered skiing, but we understand resort riding and mechanized access backcountry. Our scoring metrics reflect the demands of your typical human-powered backcountry ski experience. We make occasional references to ski mountaineering on one side and resort side-country on the other.
So you've already dished out for a pair of touring skis and some sweet AT bindings to go with them, and looking at the up-to four-figure price tag of your backcountry ski setup has you really prioritizing value as you shop for a pair of boots to round things out. Worry not! We rounded up all the specs for the boots in our review and mapped them out specifically in terms of value. The previous Editors' Choice Atomic Hawx Ultra XTD 120 and both Best Buy award-winning selections (Atomic Backland Carbon and La Sportiva Spectre 2.0) all represent what we believe to be a great value. Value shopping for ski boots usually compromises performance and weight more than durability or fit. If the boots fit you, less expensive options will hold up and you will grow accustomed to their particular performance trade-offs.
Uphill Touring Performance
Range of Motion
The range of motion of the boots we tested range from 72 degrees (more than you need) to a minimal 22 degrees, with most boots being in the 40-55 degree range. To be clear, we are talking about the forward and rearward hinging of the boot cuff, relative to the lower boot shell, all while the boot is in its touring mode. We measured this cuff range ourselves, using a standardized, repeatable method. We chiefly found the manufacturers' reference to be close to accurate. Ten years ago most boots had around 30 degrees range of motion, but with design improvements, the range of motion has increased dramatically.
With that said, there are diminishing returns on additional cuff range of motion. For example, most people don't need more than 50-60 degrees; you just aren't striding that far and your ankles don't have that much range naturally. We do think that 40 degrees of motion is WAY BETTER than 30 degrees, and users will instantly notice this critical difference. You'll see the difference going from 40 to 60 degrees and it feels better, but it isn't a dealbreaker. Backcountry ski boots with around 20 degrees of range or lower like the Top Pick Lange have an excellent walk mode for an alpine boot, but a weak walk mode for a randonnee option. They perform comparatively poor for all-day ski touring.
The best touring mode ranges in our test were found on the Scarpa Alien RS, La Sportiva Sytron and Best Buy Atomic Backland Carbon. For an alpine boot, the 22 degrees range of motion in the Lange XT FreeTour isn't bad. Further, the 55 degrees of articulation of the Tecnica Zero G Tour Pro is admirable, for an "overlap" constructed shoe. Only when skinning on flats and in scrambling terrain did we notice the limited range of motion of any of the backcountry ski boots tested here.
The Scarpa Maestrale XT has an advertised range of motion above 50 degrees. However, in use, the stiff liner and tight cuff rivets inhibit that. Further, as noted below, cuff friction within the range of motion also matters.
The range of motion is easily quantified and, once past that 35-degree threshold, makes a huge difference in one's touring efficiency. The trickier part, and arguably more important, is the friction within that range. Plastic flexion, liner binding, upper/lower interface friction, interference from ski/walk mode hardware and cuff rivet tension all inform the ease with which a boot's cuff hinges through its range of motion. The best backcountry ski boots approach zero interference within the range of motion. It is difficult to describe what creates friction, but it seems to be a combination of plastic thickness, ski/walk mode construction (pin-in-bar systems have more friction. Bar-less systems have less), and liner stiffness, especially in the ankle flexion zone.
The ultralight backcountry ski boots we tested have the least friction, while the Sytron, Backland Carbon and Scarpa Alien are in a class of their own. At the other end of the spectrum are also the heaviest boots. The Lange, Atomic Hawx, and Salomon have significant friction. Both the La Sportiva Spectre and Dynafit Hoji Pro Tour feature cuff ranges (basically 50 degrees for each) that rival those of the ultralight boots, but have considerably more friction within that range.
It is cuff friction in the Hoji Pro Tour that sets it apart from the Editors' Choice Tecnica. The Hoji boot features an innovative buckle and lever system that theoretically allows for one-move transitions between up and down. However, when used as intended, the cuff friction in tour mode is significant. If you lift your pant cuffs and individually disengage the relevant buckles you get somewhat lower cuff friction.
We tested the cuff range and friction with each of the boot cuffs unbuckled. All AT boots tour better with the cuff buckles and Velcro straps undone, which makes a good fit even more crucial. If you need the upper buckles secured for a comfortable fit (or, in the case of the Hoji Pro Tour, for transitions as advertised), you will be significantly compromising the touring efficiency.
We tested and compared all these boots mainly while ski touring but also scored some mileage on chairlifts. Downhill performance is how well the boot helped us ski down, and as a whole, stiffer boots performed better in our testing.
Overall Flex and Stiffness
Generally speaking, everyone wants, or at least thinks they want, stiffer boots. That being said, depending on your skiing ability, personal body weight and skiing style: ski boots can easily be too stiff and will work against you instead of helping you while skiing down.
For example, most 120 pound people won't benefit from a "130 flex" boot, they won't be able to absorb bumps as effectively as someone who has just a little more mass behind their ankle flexion. On the other side, a 225 pound 6'3" user will need a stiffer boot even at an intermediate ability because they just have more weight and leverage to flex the boot.A Note on Flex Numbers
First, let's be clear regarding alpine touring boots and traditional downhill/alpine boots and flex ratings: there is no official standard for flex, and it varies across manufacturers. This comes as a surprise to many, who thought those numbers (the flex index) was a standardized scale, but this is not the case. Individual companies test boots and rate their models relative to one another. Therefore, comparing different flex ratings within one manufacturer's range makes sense and will give you an accurate comparison of their relative stiffness. However, comparing flex index numbers between different companies is a different story and isn't fair to yourself or the boots.
For example, one 130 flex AT boot might be stiffer than a 120 from another company but it also could be softer. Use these numbers as just a rough guideline to helping you choose boots. Don't get too hung up on the numbers themselves. Even within the shop while trying boots on, the stiffness can feel different. How tight you buckle, liner type, and overall fit could be enough to make up for small differences in manufacturer flex ratings.
Our testers flex tested the stiffness of all the boots in our review, side-by-side indoors, and also did our best to test them one at a time while skiing multiple laps in varied terrain. In order to reduce variables, we made sure to make at least a few direct comparisons using the exact same skis and bindings. However, testing realities dictate that we can't use every boot with the same exact ski and binding set up. Our testers agreed the stiffest boots were the Lange XT FreeTour. Just below these are the Atomic Hawx Ultra XTD 120 and the newly added Scarpa Maestrale XT. The next category down holds the Salomon S/Lab MTN, Dynafit Hoji and Editors' Choice Tecnica Zero G.
After that, the next stiffest boots down were the Scarpa Maestrale RS. We'd say that the Maestrale represents the middle of the pack, as well as presenting a downhill performance that virtually no one will complain of. Just slightly softer than the Maestrale, in a class of boot that technically proficient skiers should be able to use in any terrain and conditions, are the Dynafit TLT 8 and the La Sportiva Spectre 2.0.Forward Flex Pattern.
In actual ski use, absolute stiffness is only part of the equation. For the most part, all else equal, stiff boots ski better. However, when comparing similarly stiff boots, we further differentiate by examining the subjective sense the skier gets from the forward flex pattern. Fully rigid boots, especially when pressing shins forward, are impossible to ski. One needs some degree of forward motion. The best boots flex easily at first, maybe in just the first degree of travel, and steadily meet greater and greater resistance. This resistance should ramp up steadily and smoothly, in what we call a "progressive flex."
Lightweight, stiff materials, especially carbon fiber and other types of fiberglass, constructed into "three-piece" style boots (lower shell, upper cuff, and tongue) offer less progressive flex than "overlap," two-piece boots (lower shell and upper cuff - no tongue on the shell). The best flexing boots we tested, generally, are those overlap boots at the hefty and less-touring friendly end of the spectrum. Special mention must be made here of the Dynafit Hoji and the Scarpa Maestrale XT. The Hoji and XT are both tongue style boots that flex nearly as well or, in some cases, better than an overlap boot. The cuff and ski/walk mode of the Hoji are an entirely different, tensioned design that better locks the parts in downhill mode and dramatically improves the initial feel and at least somewhat enhances the ultimate performance of the boots.
As evidenced by the Hoji and Maestrale XT, tongue boots can be made to offer a modicum of progression in their forward flex. It is this attribute that the Salomon S/Lab MTN also stands out. It isn't a ton stiffer than the bulk of the pack, but that forward flex has a progressive quality that closely simulates that achieved with an overlap shell. Tongue boots are lighter and tour better, so the pursuit of progressive flex in a tongue boot is many boot manufacturers goal. Notable is the way that Atomic has built their overlap Hawx boot to be only a little heavier than the Salomon, with even better progressive flex that skis better than the former Editors' Choice S/Lab MTN. The Tecnica Zero G is lighter than, and tours better than the Salomon with a flex pattern that is equal to or even slightly better.
Forward Lean Adjustments
Some of the boots we tested feature at least two forward lean positions and some of the boots in our review had the option to tweak that forward lean forward or backward depending on personal preference. As a whole and theoretically, backcountry skiers don't need as much forward lean as resort skiers. Folks in the backcountry are typically skiing a little slower, turning more, skiing more variable snow and have a backpack on. Fixed (or only slightly adjustable), moderate amounts of forward lean are usually adequate in touring boots.
There is a pretty big range in boot weight among Alpine Touring boots on the market. The heaviest boots we tested were the Lange XT at a stout 7 lbs 12 ounces, the lightest was the Scarpa Alien RS at a scant 4 lb 4 oz. There was a time when we were testing AT boots weighing over 10 pounds and sub-five-pounds was reserved for rando race boots, and nordic skiing. For the ski performance they deliver, the Langes are amazingly light. The Dynafit TLT8 brings average downhill performance at a fairly light weight.
For durability and all around use, provided you do not need class-leading downhill performance, you should be able to keep your pair of boots near 6 pounds. The fact that Tecnica, with their Zero G Tour Pro gets alpine-like performance into size 26.5 boots that weigh 6 pounds is a benchmark to celebrate. Seven pounders had better ski much better than the Tecnica to stand out. The Atomic Hawx fits this description. Right around the six pound mark is also the Dynafit Hoji and the Scarpa Maestrale RS.
Ultralight boots are under five pounds. The La Sportiva Sytron, Best Buy Atomic Backland Carbon and Top Pick Scarpa Alien RS are solidly in the ultralight category. You'll fly uphill, but have cold feet and limited durability. Downhill performance, after an adjustment period, won't suffer as much as you might fear. These boots don't charge downhill, but you'll adjust and enjoy yourself in a different way.
Ease of Use
We compared the "fiddle factor" of each boot in normal use. We identified how easy it was to buckle, how easy it was to switch to touring mode and ski mode as well as ease of entering and exiting the boot. In the ease-of-use category we also assessed durability. A broken boot in the backcountry is not easy to use. Some are more likely to break than others, and on some, the consequences of failed part are greater.
Entering and Exiting:
Generally speaking, boots with tongues, or three-piece boots, are easier to get into than two-piece boots, or boots that feature an "alpine wrap." Among the three-piece boots, we found the low-cuffed, super flexible ultralight boots easiest to get on and off. The La Sportiva Spectre 2.0 and both versions of the Scarpa Maestrale (RS and XT) open wide. The Lange, Atomic Hawx, and Tecnica, predictably, are hardest to get in and out of. We would be reluctant to choose these boots for expedition or multi-day use, where you'll be getting in and out of the boot while in a tent. With the overlap touring boots, remember though that you can activate the walk-mode for greater ease in getting them on and off. Overlap touring boots are easier to get on and off than overlap resort boots, because of the walk mode. Unexpectedly, the ultralight La Sportiva Sytron was very hard to get in and out of. We expect the lighter boots to be easier to get on and off than the heavier versions. The Sytron is strangely a battle to deal with. One tester, after a particularly long and high paced touring session (8000 vertical feet and 4.5 hours) was so exhausted that he couldn't get out of the Sytron on his own. Luckly assistance wasn't far away. Nor was a hot shower, cold fizzy water, and an entire pizza.
We compared how easily each buckle was to operate as well as how durable they are. Our favorite buckles were on the Salomon S/Lab MTN, Atomic Hawx, and Tecnica Zero G because they were super easy to use, even with gloves, and durable. Dynafit has slimmed down the buckle arrangement of their flagship TLT series. The TLT7 employed a complicated arrangement of cables and snaps, while the TLT8 eliminates the cable and some connections. We like the TLT8 better than we liked the closures of the 7. The buckles of the Best Buy La Sportiva Spectre are rather unorthodox, presumably to save weight. They also feature a learning curve, but are fine. There is something very satisfying about the positive snap of the very standard buckles on the overlap cuffed Atomic, Tecnica and Lange boots.
The closure system of the Top Pick Scarpa Alien RS is the most elaborate of any we assessed. The lower boot closes with the proprietary BOA closure. BOA is a knob and cable system that tightens down on your instep. The upper cuff of the Alien closes with one lever actuating cords. This same lever locks the cuff to the lower boot. Locking the upper cuff requires two cords and this long lever. The lightweight construction of these components leaves them a little vulnerable to damage. Notably, one tester had repeated issues with breaking the cords of the Alien upper lever. When any one part of this upper closure fails, the boot will ski downhill very very poorly. Carrying extra string and having the energy and wherewithal to make a field repair is crucial to using the Alien RS.
The upper cuff closure of the Dynafit Hoji is about as complicated as on the Alien RS. The whole cuff is designed with two major goals in mind; the cuff locks together super securely, and the user can switch between tour and ski mode with just one lever. The result, though, is a system that is more complicated than other options and more vulnerable (theoretically… we didn't have any actual problems) to failure. Once you are accustomed to the "Hoji Lock", you can indeed make transitions with just one move. However, the tour mode, when used this way, involves more cuff friction than anyone wants. The "pants down always" transitions that Dynafit claims are novel, but not a useful reality when undoing the buckles completely results in much better touring ease.
Most of your backcountry ski day will be spent going uphill. Another good portion is downhill. Many people love these things, and love of one or both of these things is what draws people to backcountry skiing and ski mountaineering. Another large chunk of your day is spent in transitioning between the two. That isn't nearly as fun. Therefore, it is nice when equipment makes it easy to get through the transitions without much drama. Your boots will have two distinctly different modes, and switching those modes involves buckles and adjustments. The best transitioning boots make this process easy.
The Top Pick Scarpa Alien RS is the fastest boot to transition. All that is required to switch modes is one lever accessible without moving your pant cuffs. The Dynafit Hoji should be as simple, but the walking articulation in "fast change mode" is significantly limited. Next is the La Sportiva Sytron. With the Sytron, once you have buckled into tour mode, there is one forefoot and one cuff lever move to tackle. The one upper lever tightens the boot around your cuff and locks cuff to lower boot. The Dynafit TLT8 changes between modes with an upper buckle and a cam-lock power strap. No other product in our test matches the transition ease of these four. The next closest competitor is the Salomon S/Lab MTN. It has two main buckles, a ski/walk mode lever, and a similar cam-locked power strap. To go from walk to ski mode (and vice versa), the user manipulates the cuff buckle, the ski/walk lever and the power strap.
The Best Buy Atomic Backland Carbon is solidly in the ultralight, fast category, but its transitions are more complicated. To go between uphill and down you have to lift your pants cuff and change rear lock, cuff buckle, and power strap. It's not that bad, but it isn't as slick as some other options in this weight class.
Contrast these with these others that complicate transitions. The Top Pick Lange XT FreeTour 130 and Editors' Choice Tecnica Zero G Tour Pro both have four buckles, a rear ski/walk mode lever, and a power strap, all of which usually require adjustment between up and downhill mode. The Atomic Hawx Ultra XTD 120 has the same configuration as the Lange and Tecnica, requiring all the same steps. One major advantage of the Atomic Hawx and Tecnica over the Lange is that the Atomic and Tecnica have a fully external ski/walk mode lever. While the mode changing levers of the Lange sometimes gave us trouble, the Hawx and Zero G go easily every single time.
The La Sportiva Spectre 2.0 and Scarpa Maestrale RS and XT have buckle and transition setups much like the Lange and Hawx. These two are discerned from one another by the Scarpa Maestrale RS "instep" buckle. Many users really like this buckle configuration (the Hoji boot also has it) that pulls and holds the skier's heel down and back.
Comfort and Fit
Comfort is a little relative as each person has a different foot shape, width, and size, but we did our best to compare boots for touring and downhill comfort as well as how each liner affected fit. Our test team represents a variety of foot shapes, all in size 26.5. In years of comparisons now, it seems that our lead test editor has feet that are right in the middle of the road. They aren't super wide, nor super narrow. It is comparative, qualitative assessment, largely based on the experience of our lead testers that we report. With length fixed at 26.5, for test and comparison purposes (in some cases, given the different shapes and volumes of different models, we might opt to size up or down for our use), we compared rough estimates of the boot's volume and additionally noted toe box, overall volume, and heel pocket retention/volume. We also commented on general impression of width, though volume is a better metric.
The Salomon S/Lab MTN and La Sportiva Sytron fit on the narrow, low volume end of the spectrum. The Lange XT FreeTour, Tecnica Zero G Tour Pro, and Dynafit Hoji are neutral in fit. The Scarpa Maestrale RS and Top Pick Scarpa Alien RS seem to be higher volume than the others. One tester found the Maestrale XT to be narrower than he expected a Scarpa boot to be. Other testers did not have this experience. Special mention must be made of the Atomic Hawx. These start with a pretty neutral fit, but are made of special plastic that is far more readily adjusted than the plastic used in the other boots. They can be easily "heat molded" to accommodate a wide range of foot shapes and issues. The Atomic Backland Carbon is high volume, while the newcomer Dynafit TLT8 is optimized for very wide, high-volume feet.
After the fit, there are comfort concerns. Fit is king, but there is one major non-fit-related comfort criteria we looked at. For some boots to get lighter, materials in both shell and liner have gotten thinner. Thinning the liner serves two major purposes. First, it is less material. Therefore it is lighter. Additionally, and less obvious, but the thin shell materials offer better support when they fit closer to your foot. Any shell material offers better support when it is close to your foot, but thin shell materials need that performance bump more. In the end, some liners are thinner than others. For bony feet, no matter how well you fit the boots, thin liner boots are more prone to cause pressure points. The ultralight La Sportiva Spectre 2.0 seemed especially prone to this, causing bruising on the ankle bones of two testers each.
We find it surprising how seldom the insulation value of ski boots is mentioned in other online reviews. Skiing regularly takes place in cold conditions. Your boots should accommodate that. With a wide range of construction styles and materials, we found variation in the warmth of the boots we selected for review. Thicker liners and thicker shells make for warmer boots. More material between your warm foot and the cold outside slows the transfer of heat. What this means is that there is a pretty clear correlation between the weight of the boots and the insulation value. Of course, fit matters, but that can be adjusted. The other thing that matters is the "density" of the liners. Softer foam in the liners seems to feel warmer.
The ultra-light boots are the least insulating, while the beefy boots are the warmest. A notable exception is the Scarpa Maestrale RS. It is among the lighter four-buckle boost in the test but the liner is thick and fluffy. Scarpa works with Intuition Brand for their liners and Intuition liners are proven and highly functional. Many will replace stock liners with Intuition liners for performance, warmth, and comfort.
The least insulating boots in our test are the La Sportiva Sytron, the Scarpa Alien RS and the Atomic Backland Carbon. It is no coincidence that these are also the lightest boots in our test. Users of lightweight backcountry ski equipment, especially footwear and clothing, rely on speed and movement to keep themselves warm. This is almost always a fine solution. However, when things go south and one is forced to stand still for any reason and for any length of time, the choice to bring no extra jacket and glorified sneakers as boots seems a little sillier. It is a blast, literally, to move unencumbered through the mountains, but do so knowing the consequences of that choice.
Warmer options include, as mentioned above, any of the heavier boots. The Editors Choice Tecnica Zero G Pro Tour can be configured for acceptable warmth. The stock liner is thin and cold, but the boot is supportive enough to "size up" and insert a thicker aftermarket liner. You get greater comfort and warmth with this strategy, with only a little compromise in downhill performance.
Fit and application are the primary criteria by which you will choose boots. Thanks to an exploding interest in backcountry skiing, your options are ever expanding. There are now multiple fit options at every level of performance. With this in mind, we recommend you think long and hard about how you wish to strike the uphill/downhill balance. If you are less experienced in the backcountry, consider that you will quickly learn to appreciate lighter gear on the way up and nearly as quickly adjust to the downhill performance of that lighter gear. On the other hand, you will just as quickly learn to dread dragging heavier gear up a mountain and reap limited marginal returns for the way down. Go lighter than you think, to a point.
— Jediah Porter