Happy feet make happy backcountry skiers. We chose a cross-section of kicks that represent the best of the best and covers a wide range of applications. Alpine Touring (AT) ski boots are inherently a compromise between two main competing factors. What makes a boot go uphill easily is almost diametrically opposed to that which makes a boot go downhill well. Each boot model, then, sits on a continuum between being optimized for the up and being optimized for the down. We have selected boots that sit evenly along this continuum, with a focus on products near the popular middle ground. In reading our review, you will learn not only about the exact products we tested but how to extrapolate our findings to products that didn't make the cut but might be worth your consideration. For 2018 we tested 12 pairs of boots, including two brand new products that each earn awards.
The Best Backcountry / AT Ski Boots of 2018
|Price||$849.95 at Amazon|
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|$699.95 at REI|
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|$869.95 at Backcountry|
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|$799.95 at REI|
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|$629.99 at Amazon|
|Pros||Light, excellent freedom of motion, easy to use, skis downhill as well as any average touring boot||Great downhill performance, progressive forward flex, reliable buckles and ski/walk mode||Light and dextrous in tour mode, satisfactory ski performance||Excellent skiing, serviceable touring performance||Versatile, lightest four buckle boot in our test (if not the entire market)|
|Cons||Limited crampon compatibility, not as warm as the warmest boots available||High friction in range of motion, smooth sole||Limited warmth, downhill performance takes getting used to, wide fit and Scarpa doesn’t recommend shell modifications||Narrow fit requires work for most feet||Outdated design, limited tour mode range and freedom of motion|
|Bottom Line||The TLT 7 is the result of decades of refinement and the performance shows; the proven attributes are welcome, and the innovative refinements work well enough.||This is a ski touring boot that skis downhill almost as well as a resort boot.||These are specialized high-speed ski mountaineering boots for the all-around user.||An excellent, modern AT ski boot for the masses.||The Cosmos is a classic ski touring boot, with classic design cues.|
|Rating Categories||TLT7 Performance||Hawx Ultra XTD 120||Scarpa Alien RS||Salomon S/Lab MTN||Scott Cosmos III|
|Uphill Performance (25%)|
|Downhill Performance (25%)|
|Comfort And Fit (20%)|
|Ease Of Use (5%)|
|Specs||TLT7 Performance||Hawx Ultra XTD 120||Scarpa Alien RS||Salomon S/Lab MTN||Scott Cosmos III|
|Weight. 26.5. Pair||4 lbs 8 oz||7 lbs 5 oz||4 lbs 4 oz||6 lbs 14 oz||6 lbs 3 oz|
|Range of Motion. Degrees.||55||36||72||41||32|
|Binding Compatibility? Tech only, or Tech and DIN AT standard, or Tech, DIN AT and DIN Alpine/WTR||Tech only||WTR, Tech, and DIN AT||Tech only||Tech and DIN AT||Tech and DIN AT|
We've added two entirely new boots to the review for your consideration. We used these to ski almost 30 days in Wyoming's Teton and Absaroka ranges, occasionally comparing back to kicks we have a deeper experience with. We're also testing skis and bindings, pounding through the willows and stumps and working around unprecedented avalanche hazard, all to bring you the best backcountry ski reviews on the internet. Scope our updated boot review for the true state of the art.
Best Overall Backcountry Ski Boot
Dynafit TLT7 Performance
The Dynafit TLT 7 Performance wins our OutdoorGearLab Editors' Choice for best alpine touring boot. It combines nearly the best uphill performance with downhill performance that exceeds expectations. The TLT 7's 55 degrees of cuff touring mode range of motion, low weight, and low friction cuff articulation helped make it one of our favorite touring boots. Combine that with ski performance that will get most skiers through most terrain in most conditions, means it's worth everyone's consideration. The TLT 7 excels at ease of transitions. One can switch from tour to ski mode in one move. In a rare move, we granted two Editors' Choice awards. As we compared boots and agonized over the scoring metrics, it became clear that two boots would share the highest scores, well ahead of the rest of the pack. Interestingly, these two boots are fairly different from one another. As you compare the TLT 7 to the Atomic Hawx Ultra XTD 120, consider your apprehensions about your backcountry boot purchase. Are you concerned about the uphill performance, primarily? If so, the TLT 7 is your call. The TLT 7 tours almost as well as a Randonnée race boot and skis downhill as well as your average, "typical" backcountry ski boot. That is high praise and a testament to how far BC ski gear has come.
Read review: Dynafit TLT 7 Performance
Also One of The Best
Atomic Hawx Ultra XTD 120
Overall, the Atomic Hawx Ultra XTD comes awful close to the performance scores of the TLT 7. They tie for the top mark. With backcountry ski boots, compromise is the name of the game. The ideal shoe would climb like a trail runner and descend like an alpine race boot. These attributes, however, are mutually exclusive. In enhancing one, the designers have to compromise the other. As technology advances, and with the best products available, these compromises are ever narrowing. In the case of the Atomic Hawx Ultra 120, it skis almost as well as an alpine resort boot and tours as well as your average AT ski boot. This is unheard of, and oh-so-appreciated. Consumers apprehensive about compromising downhill performance now have a touring boot choice that performs well on the way down while serving very very well on the way up as well. The Atomic Hawx tours like an average touring boot, and skis downhill like the best around. The TLT 7 skis downhill like an average touring boot, and tours like the best around. You have great choices right now. Our editorial team can't decide. Both of these top scorers are excellent products, with different balances of essential criteria.
Read review: Atomic Hawx Ultra XTD 120
Best Bang for the Buck
Dynafit Radical Boot
With the uphill performance of Dynafit's much more expensive boots and serviceable downhill performance, the Dynafit Radical Boot is an excellent entry to the field at $550. You can buy other AT boots for a similar price, but those do not tour nearly as well as the Radical. Like Dynafit's other boots, maybe the biggest downside is there is a little more "fiddle factor" to get used to these. On the other hand, like with the rest of their line, after a few days of touring, you'll get it figured out. The Radical is also quite heavy, as compared to boots with this level of downhill performance. At this downhill performance level, for instance, the La Sportiva Spectre 2.0 is a pound and a half lighter for the pair, but $200 more. In the end, for new consumers looking for a good deal, the Radical has a vast range of cuff motion, durable construction, and serviceable up and downhill performance.
Read review: Dynafit Radical Boot
Best AT Boot for Ski Mountaineering and High-Speed Touring
Scarpa Alien RS
The best boot 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! The Alien RS is, in some respects, similar to the Editors' Choice Dynafit TLT 7 Performance. When looking at our entire test roster, they both fall into the ultralight category. The TLT 7 skis downhill better and will be more durable. The Scarpa, though, has a lower-friction uphill mode, is lighter, and can be used with standard step-in automatic crampons. For these reasons, it steps away from its close competitor when the objectives are more in the ski mountaineering realm. Lastly, 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.
Read review: Scarpa Alien RS
Top Pick for Hard Charging Downhill Performance
Lange XT Freetour 130
The Lange XT FreeTour 130 was 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 the only boots available that will work with tech style touring bindings AND with resort alpine bindings (the resort bindings must be WTR compatible). Even human-powered users should consider the Lange. Our lead test editor and full-time backcountry ski guide contemplated them for day-to-day guiding, where comfort, downhill performance, and warmth have great value. We chose the Lange over the similarly constructed Tecnica Zero G Guide because the Lange skis downhill a little better and has a more forgiving fit. The Lange fits many feet straight out of the box, while the Tecnica requires work for more users.
Read review: Lange XT FreeTour 130
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 how we expect you'd use them and reported our findings below. We compared and scored them in six categories described below. 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 now quadruple digit 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 Best Buy award winning Dynafit Radical and Editor's Choice Atomic Hawx Ultra XTD 120 both fall towards the lower right of the chart below, thus representing what we believe to be a great value. Hover over each dot in the chart to see how the rest of the competition stacks up.
Uphill Touring Performance
Range of Motion
The range of motion of the boots we tested range from more than you need (72 degrees) to a minimal 20 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. Five 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 deal breaker. Backcountry ski boots with around 20 degrees of range or lower like the Lange and Tecnica 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 Dynafit TLT7 Performance, Scarpa Alien RS Atomic Backland Carbon, Arc'teryx Procline Carbon Lite, La Sportiva Spectre, and Dynafit Radical. Interestingly, the Scott Cosmos III is among the lightest four-buckle boots we tested, but its cuff range is surprisingly small. We expected it to be higher than the 32 degrees we measured. For what is an alpine boot, the 22 degrees range of motion in the Lange XT FreeTour isn't bad. Further, the 36 degrees of articulation of the Atomic Hawx Ultra XTD 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.
Special mention, as it pertains to cuff range of motion, must be made of the Arc'teryx Procline Carbon Lite. As noted above, the standard fore-aft range is admirable. On top of that, it has intentional and real lateral flex in tour mode. For tough skinning, scrambling, and even technical climbing, this lateral motion is interesting and worth considering. For most ski touring and ski mountaineering, it isn't a huge deal. For technical climbing though, this can be a game changer.Cuff Friction
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, 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. The Procline Carbon Lite, the TLT 7, Scarpa Alien, and Atomic Backland Carbon are all in a class of their own. Among those, the TLT 7 has more friction than the other three. At the other end of the spectrum are also the heaviest boots. The Tecnica, Lange, Fischer, Atomic Hawx, and Salomon have significant friction. Interestingly, the Scott features sub-optimal cuff range but lower-than-expected friction amounts. Both the La Sportiva Spectre and Dynafit Radical 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 when looking at the tour mode of the Dynafit Radical that one finds the limitations of this budget product. The great range is appealing, but the friction is just too great to be truly above standard.
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. This makes a good fit even more crucial. If you need the upper buckles secured for a comfortable fit, you will be significantly compromising the touring efficiency.
We tested and compared all these boots both while mainly 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 lb 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 lbs 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 in that there is no official standard that exists across all 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 and boot 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, all with the same skis (Incidentally, most testing was done using our Editors' Choice Volkl VTA 98 backcountry ski and its predecessor, the Volkl BMT 94) in order to reduce variables. Our testers agreed the two stiffest boots were the Lange XT FreeTour and the Tecnica Zero G Guide. Just below the support of the Lange and the Tecnica is the Editors' Choice Atomic Hawx Ultra XTD 120. The Salomon S/Lab MTN was not soft, but noticeably softer than these three "overlap constructed" boots and comparable to the Fischer Transalp Vacuum TS.
After that, the next stiffest boots down were the Scott Cosmos. We'd say that the Scott Cosmos 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 Scott Cosmos, in a class of boot that technically proficient skiers should be able to use in any terrain and conditions, are the Dynafit TLT 7 and the La Sportiva Spectre 2.0. The Arc'teryx Procline Carbon, Dynafit Radical, Scarpa Alien RS and Atomic Backland Carbon share roughly comparable, and relatively minimal, stiffness quotient. However, each brings other attributes that balance things out for them.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 are those overlap boots at the hefty and less-touring friendly end of the spectrum. 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 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.
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, backcountry skiers don't need as much forward lean as resort bound skiers because folks in the backcountry are typically skiing a little slower, turning more, skiing more variable snow and have a backpack on. So the 16-20 degree forward lean is typically enough for most users, especially because most alpine touring bindings have more ramp/delta angle (toe is lower than the heel) to make up for the boots lack of aggressiveness.
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 TLT7 brings average downhill performance at nearly the lightest weight we've ever reviewed.
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 under seven pounds. The fact that Salomon, with their S/Lab MTN gets alpine-like performance into size 26.5 boots that weigh under seven pounds is a benchmark to celebrate. The Editors' Choice Atomic Hawx Ultra XTD 120 is half a pound heavier than the Salomon, edging north of that seven-pound threshold. Swap the stock liners for an aftermarket product, though, and you quickly shed more than that half pound right off. Aftermarket liners will tour better than the Atomic liners but ski a little more poorly. We know this because we tested this way, too. We go the extra mile. These low weight marks have a price. Literally. The Best Buy winning Dynafit Radical is the second heaviest boot we tested, with downhill performance exceeded by boots a little more than half their weight.
Ease of Use
We compared the "fiddle factor" of each boot in normal use. We sized up 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 a failed part are greater than on others.
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 opens wide, while the close competitor Scott Cosmos III is the hardest three-piece boot to get into. The Lange, Atomic Hawx, and Tecnica, predictably, are hardest to get in and out of. We wouldn't 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.Buckles
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 Scott Cosmos because they were super easy to use, even with gloves, and durable. We were initially skeptical of the super-simplified buckle system on the TLT 7. All functions, from lower boot tightening to ski/walk mode, are accomplished with a single upper cuff buckle. It takes some getting used to, but it is streamlined, fast and stays out of the way of damaging rocks while walking. The buckles of the 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 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.Transitions
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. Next is the Editors' Choice Dynafit TLT 7 With the Dynafit, once you have buckled into tour mode, there is one lever and one optional, fast power strap move to tackle. The one lever tightens the boot around your cuff and locks cuff to lower boot. The strap is a cam-lock style that cinches tight and pulls loose with a single tug. No other product in our test matches the transition ease of these two award winners. 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.
Contrast these with these others that complicate transitions in two very different ways. The Atomic Backland Carbon features a total of three buckles and a power strap and an interchangeable tongue. To go from uphill to downhill mode the stored tongues must be removed from one's pack, inserted into fully loosened boots, and then all buckles and straps must be re-secured. The Top Pick Lange XT FreeTour 130 has four buckles, a rear ski/walk mode lever, and a power strap, all of which usually require adjustment between up and downhill mode. The other Editors' Choice winner Atomic Hawx Ultra XTD 120 has the same configuration as the Lange, requiring all the same steps. One major advantage of the Atomic Hawx over the Lange (and the Tecnica, for that matter) is that the Atomic has a fully external ski/walk mode lever. While the mode changing levers of the Tecnica and Lange sometimes gave us trouble, the Hawx goes easily every single time.
The Tecnica Zero G Guide, the La Sportiva Spectre 2.0, the Scott Cosmos, and the Best Buy Dynafit Radical all have buckle and transition setups much like the Lange and Hawx. The Fischer Transalp Vacuum is similar, except that it has one fewer buckle.
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, Tecnica Zero G Guide and Arc'teryx Procline Carbon Lite fit on the narrow, low volume end of the spectrum. The Lange XT FreeTour, Dynafit Radical and Dynafit TLT7 are neutral in fit. The Scott Cosmos III, Top Pick Scarpa Alien RS and the Atomic Backland Carbon seem to be higher volume than the others. Special mention must be made of the Fischer Transalp Vacuum TS and the Editors' Choice Atomic Hawx. These both 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.
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 attribute 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 and Atomic Backland Carbon 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 Scott Cosmos III. It is the lightest four-buckle boot in the test but the liner is thick and fluffy. These liners may very well "pack out" with time (we didn't test long enough to ascertain exactly how much), losing both support and insulation value, but they offer warm protection when new.
After determining the kind of days you plan to be spending in these boots, and where, other factors will also need to be considered. Fit, material, and performance are just a few important factors making this purchase a hard decision to make. Using this review, we hope to give you a clear idea of what boots will best suit your needs.
— Jediah Porter