How to Choose Alpine Ski Boots
Fit, Flex, and More
Selecting a new pair of ski boots can be difficult, to say the least. Backcountry Gearhead Brandon Orloski, a former bootfitter who has worked in ski shops across the country for ten years, offers some guidance to help you select just the right pair of boots.
You many not realize it, but your ski boots are the most important piece of your ski equipment. It’s funny because most people will pay around $100 for a lift ticket, but skimp when it comes to their boots. It really is like the foundation of a house—with a bad foundation, the house will crumble. Likewise, wearing boots that don’t fit right will cause pain and discomfort that can ruin a day of skiing. And if they don’t fit right you won’t be able to control your skis as well as you should.
Your skiing style
The first thing you’ll want to consider is the type of terrain that you’ll be skiing and how you’ll be skiing it, because these will affect your boot selection. There are other factors that will affect your choices—like flex, fit, and feature set—but this can help you figure out where to start looking.
Like skis, boots are roughly divided into the following categories:
Most all-mountain boots have a good blend of carving and freeride characteristics. This boot will work for skiers of any level, from beginner to expert, who skis anywhere on the mountain. Some models feature a walk mode that makes it easy to hike around the mountain or get around the resort. Finding the correct flex and width will depend on the boot, your foot shape and skiing ability (more on that later).
Freeride boots usually take their flex and fit cues from carving and racing boots, along with a more upright stance and more anti-shock features, since freeride skiing often includes high speeds and big airs. Though not as burly and expensive as a race boot, freeride boots are seeing a bit more popularity among skiers looking for a bit more beef that what’s available in all-mountain boots. Most models will have rubber or WTR soles. Finding the right boot will come down to the fit, flex, width, and skiing ability.
Also known as AT boots, these boots are for people looking to get into the backcountry or possibly take one chair lift to access it but hiking or skinning to skiing for the rest of the day. These ligherweight boots are designed to work with pin-style Tec bindings or alpine touring bindings. The soles of these boots feature aggressively lugged soles, often Vibram, that deliver great grip for dicey ridge crossings and solid footing on the approach. They have walk modes for easy hiking and skinning, with some models offering the range of motion of a backpacking boot. Finding the right touring boot depends on your foot, skill level, and your agenda in the backcountry.
Park & Freestyle
Park and freestyle boots have a more roomy fit, a very upright stance, light weight, and as much shock absorption as possible since they will see a lot of takeoffs and landings. Since there is such an upright stance and a softer flex, a carved turn is more difficult to pull off in these boot; skidding turns provides a better comfort level. Park and freestyle boots are usually the easiest boot to fit and the cheapest, but if you’re looking to get a lot of use out of them outside of the park, you’ll have to head to the top-of-the-line park and freestyle boots.
How Stiff Should Your Boot Be? Boot Flex Explained.
Once you start looking at specific models, you’ll notice that they have different versions of the same boot, usually distinctions between different levels of flex. When you’re wearing a ski boot, as you move your knee forward, the cuff of the boot will move some, too. How easily the upper shell hinges forward is measured using a numeric flex index scale. This scale usually ranges from around 50 to 130, with the softest, most flexible boots (generally, kids’ boots) measuring around 50 and the stiffest race boots measuring around 130+. It’s important to pay attention to this because the proper flex will not only let you maneuver the ski as it was intended, but it will also be more comfortable than being stuck in a boot that’s too stiff for your strength or ability level.
Determining the right flex for your boot if influenced by your skiing ability, style, and your weight. A stiff boot is good for a skier who skis very aggressively, since it will hold up better at faster speeds and offer more support. Weight comes into play as well: even if you are not flying down the mountain but are heavier, you can flex a boot more easily than someone who is lighter or not as strong.
If this sounds confusing, you can just go with the general rule of thumb that a beginner adult skier should look for about a 70-90 flex (with lighter skiers being at the lower end), an intermediate skier can be in a 90-110 flex boot, and an expert skier should be in a 110-130 flex boot. But as you can see, there are so many variables and boot styles available, I urge you to contact me or an experienced Gearhead before purchasing to determine what flex boot is right for you.
Manufacturers measure the interior of a boot’s shell in millimeters at the widest part of the forefoot. This number will be expressed as “last width.” Ski boots will range from usually a 97-104 last, 97 being narrow and 104 being wide. And while you don’t need to have an exact forefoot width measurement, it’s good to know that a 100mm last width is fairly standard (race boots usually feature last widths ranging from 95-97mm, while 104mm is considered “wide”). If you usually wear wide, “EE” tennis shoes, for example, it’s a safe bet that a 104mm last will be an appropriate match. If you wear a standard “D” width shoe, then a 100mm last will most likely fit your foot the best.
To some degree, last width will also affect performance. Regardless of foot size, racers prefer the narrow lasts because that close (to the point of painful) fit delivers the instant response that they need. At the other end of the spectrum, wider last widths may be preferred even by average-footed skiers who are more focused on all-day comfort than performance.
Often, ski boots will come in different volume options, generally low-volume and mid-volume. If you have a high arch or wide, thick feet, a mid-volume (MV) boot may be for you. On the other hand, if you have flat and/or very narrow feet, you may look for a low-volume (LV) version. Boots with wider lasts normally have more volume and boots with narrower lasts normally have less. Three-piece boots such as Full Tilts or some Dalbellos sometimes work better for someone with a high instep.
Men’s vs. Women’s Boots
The differences between men’s and women’s boots aren’t just the colors. Boots were generally unisex in the neon ’80s before carving was introduced and ACL tears in women began to rise. Boot companies figured out that if the cuff height were lowered it would allow a woman’s knee to flex more naturally, due to a women’s lower center of gravity.
Women’s boot sizes are a bit on the smaller size as well, since women generally have a skinnier forefoot (Women average a B-C width while Men are more like C-D width) and have sizes that range down to a 21.0 Mondopoint for the smaller lengths. The stock liners are different as well, with the upper rear splaying out earlier since women’s calf muscles extend a bit further down the leg.
Walk-Ride Mode and Walk-to-Ride Soles
What started out as a staple feature on alpine touring boots, ‘walk mode’—a switch, usually in the rear of the boot, that disengages the lower shell from the upper shell—is now showing up on many all-mountain and freeride boots as well. This allows for more ankle articulation, which is great for when you have to hike a boot pack. When you’re ready to ski, lock it down into ride mode.
In addition, you will notice some ski boots are ‘Walk to Ride.’ This means is that the sole of the boot has more of a rockered shape, allowing the toe of the boot to roll a little easier when you are walking around the resort or on mountain. If you get a boot that is Walk to Ride you need to make sure that you have a compatible binding.
Number of buckles
Over the last decade we’ve seen the prevalent number of buckles decrease on a ski boot from four to three and even to two. The fewer buckles the boot has the less weight the boot carries; also, buckle placement can help with heel retention and a more progressive flex. Does this mean four-buckle boots are on their way out? Heck no. Four-buckle boots still have the best traditional hard snow feel along with a stiffer flex and better responsiveness.
When you put a ski boot on right out of the box, that is the tightest that boot will ever feel. The more you ski in it the more the liner will pack out and open up to your foot. There are some higher performance boots than come with custom thermomoldable liners that speed up this process by forming to your foot and ankle, either with heat being applied or just as the boot warms up as you wear it. All stock liners are thermomoldable to a small degree, but these high-end liners last much longer and retain their shape much better. Most boot companies license the liner company Intuition to supply their liners for them so they are of very good quality and well worth the price if you are looking for a higher performance custom fit.
Most alpine boots come with one-piece soles, referred to as alpine/DIN soles. They’re mostly flat and are used with ‘regular’ alpine DIN bindings. But as I was saying before, we’re getting further and further out there when it comes to going from resort to the sidecountry and backcountry, so certain lines of all-mountain and freeride boots do have interchangeable soles. These are usually switched out through loosening a few allen bolts underneath the toe and heel of the soles. There are two main types that are compatible with alpine boots:
- Alpine Touring – a less flat, more lugged design to these soles give the boots extra grip for hiking on rocky or icy surfaces, as well as the ability to use in alpine touring bindings with a frame design.
- Tech – these soles have a similar lugged design of the Alpine Touring soles, but they have tech fittings as well for tech bindings such as Dynafit Radical and Marker Kingpin bindings.
Now that you’re zeroing in on your model, and are ready to buy, you need to make sure you’re getting the right size. Ski boot sizing is different from shoe sizing—it uses an international foot measuring system called Mondopoint, which is the length of your foot measured in centimeters. You’ll often see boots marked with this number on the toe and heel lugs, expressed in whole (alpine touring boots) and half sizes.
While many manufacturers often include a size conversion chart for their boot shells, you can simply determine your Mondopoint size by tracing your foot on a piece of paper. Then, measure from your heel to the end of your longest toe, in inches, and multiply by 2.54 to convert to centimeters. Round this number to the nearest half centimeter, and this is your Mondopoint size. For example, a foot measuring 10.5 inches is 26.67 centimeters long, or 26.5 Mondopoint. I recommend using this method over checking a size conversion chart for a more accurate fit.
Once you have your new boots in hand, how do you know the fit is right? As mentioned before, part of it will depend on your level of ability. As the video below demonstrates, two fingers behind your heel and the back of you boot is described as a ‘comfort fit,’ best for someone who does not ski often or is just spending time with the family on the slopes.
For a ‘performance fit’ you should be able to fit one finger behind the heel and back of the boot. This is for someone who is a good skier or progressing. With a closer fit, you’ll get better handling out of your skis and can work on improving. Then there is a ‘race fit.’ You should have half a finger or no room behind your heel and the shell of the boot. This is for an expert skier looking for maximum performance. You might need to do what most racers do, and get some boot work done at the shop, such as getting the shell molded or adjusted for your foot.
The Finishing Touches
Everyone’s foot is different, so it’s rare that a boot is going to fit perfectly right out of the box. Taking the boot to a bootfitter for the final customization—heat-molding, ‘punching out’ the shell, getting a custom footbed—can make a huge difference in how the boot feels and performs.
There are also a few things you can purchase to enable you to get the most performance and enjoyment from your new boots:
After-market insoles: Unfortunately, most insoles that come with ski boots are usually little more than thin, flat pieces of foam. I consider adding a pair of better insoles a must. Most people have some sort of arch in their foot, abut without any arch support or a solid foundation your foot will flatten out. This will make your toes jam into the front of your boot. Having that footbed in the boot will keep your arch at its proper height pulling your toes back from the front of the boot and giving you better power transfer side to side. Feel free to contact me with any questions on picking out a proper footbed.
Customizable Intuition liners: Unless the boot you’re buying comes with an Intuition liner already, swapping the stock liner out for one of these heat-moldable liners that can be shaped to fit your foot precisely will make a big difference in your comfort and, to a point, your skiing performance.
Heated insoles: Game changer! Have you tried everything and just can’t keep your feet warm? If so these are what you need. They can work with any ski boot, and feature a heating element that goes under the foot and has different levels of heat and will keep your feet warm throughout the day.
Boot dryers: Not only will you be happy not to have to put on wet boots in the morning, but drying your boots after use will prolong the life of your liners and keep them from getting stinky. The key is to use a product designed just for this purpose (as opposed to sticking a hair dryer in them or propping them near the fireplace), so you don’t accidentally melt things down or wreck any investment you’ve made in custom heat-molding.
The right socks: You’re not still skiing in gym socks, right? Good. But even with synthetics or wool, the key is to get the right thickness. Boot liners are made to be warm (some even with Thinsulate) so you don’t need the old-school big thick wool socks. To get the most out of your properly fitting ski boot you should be wearing an ultra-light ski sock. And contrary to what you might expect, your feel will be warmer in thin socks. Too-thick socks are a major contributor to cold toes because they crowd your feet inside the boot and cut off your circulation.