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: all-mountain, freeride, touring, and park & freestyle.
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 all-mountain boots, with the added compatibility with multiple binding norms. Most models use a GripWalk sole, for ease of getting around between runs or on bootpacks, and have a walk-mode as well. Freeride boots are commonly compatible with both tech (pin-style) bindings as well as alpine bindings, as long as those alpine bindings work with the GripWalk sole.
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 lightweight boots are designed to work with pin-style Tech 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: whether uphill laps from a resort base or long missions into the forest.
Park & Freestyle
Park and freestyle boots have a more roomy fit, a very upright stance, light in 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 boots; 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.
Boot Flex Explained
When you bend your knee and lean into the front of a ski boot, that movement is impacted by the flex level of the boot. The scale 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+. This number is not a scientific standard, so you may find that boots labeled 120 between different brands feel slightly different. Most brands offer the same model boot, for example, the Nordica Promachine, in several flex options to best suit different skiers.
A general rule of thumb is 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. Your skiing ability, weight, and relative strength all impact the ideal boot flex for you: one expert-level skier who is lighter weight may use the same flex of a boot as an intermediate, heavier-weight skier. It’s very helpful to try on several boots with an experienced boot fitter to see what suits you best.
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 97-104mm last, 97mm being narrow and 104mm 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 shoes, for example, it’s a safe bet that a 104mm last will be an appropriate match. If you wear a standard 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 fit delivers the instant response that they need between boot, binding, and ski. 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, from low volume (LV), mid-volume (MV) to high-volume (HV). For skiers with narrow, slim feet, low volume boots can offer a closer fit for better control. For skiers with wider, higher-volume feet, mid or high-volume boots can provide a better fit. 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 are more than just the shell color; we’ve thankfully evolved from the days of “shrink and pink” women’s equipment. For folks with smaller feet, women’s boots offer sizes on the small end of the spectrum, usually down to 22.5, whereas men’s fit boots usually only offer down to a 24.5.
Men’s fit boots are generally wider, both in the forefoot and the heel cup. If you have a narrower heel or foot, a women’s fit boot will offer a more secure fit. Women’s fit boots also have a lower cuff heigh than a men’s fit boot, to correlate with the shape of most female-bodied skiers.
Walk-Ride Mode and Walk-to-Ride Soles
What started out as a staple feature on alpine touring boots, ‘walk mode’—a lever, usually in the rear of the boot, that releases the hinge point between 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–this information can be found under the “ISO” number for a boot and binding. SImply make sure that your boots and bindings have the same ISO number, and you’re good to go.
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. Most all-mountain and freestyle boots use four buckles for greater heel retention and a closer fit, while many touring boots use fewer buckles as weight savings for your climb up the skin track.
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. After market liners, like Inuition, are also available to customize the fit of your boot.
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. Certain lines of all-mountain and freeride boots have interchangeable soles. These are usually switched by 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. This number is only a starting point, as you’ll need to check the fit of the boot to ensure it’s the right size for you.
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. You can do a shell fit, by removing the liner of the boot, stepping into the shell, and checking the dimensions while standing upright. A bootfitter at a ski shop can also help with this step. Two fingers behind your heel and the back of the 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 skiing in cotton 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 feet will be warmer in thin socks, as too-thick socks can crowd your foot and limit circulation where you need it most.