How to buy a ski boot
A ski boot is a piece of athletic footwear and should be sized accordingly. Soccer shoes and ice skates are examples of proper fit.
A boot that is too large or does not properly match to the contours of the foot will present some or all of these symptoms:
Toes that seek grip or actively clench
A general lack of feel for the snow
Poor skiing posture
A feeling that your skis are answering to a master other than you
Jerky or sequential movements while skiing
Lack of circulation, pins and needles
Cramping and pain
Arrested progress as an athlete
A general and growing disinterest in the sport.
If your ski boots are the same size as your street shoe, you can immediately assume that they are too large.
Do not assume that a particular boot is good for you just because your best friend or skiing idol has them.
Do not assume that a boot is good to go right out of the box. The designers do not keep a likeness of you on their desktop for inspiration. Unless you are particularly fortunate, a boot that is sized correctly may need at least a little work before you can use it comfortably.
When you pay for a ski boot, it is best to believe that you have purchased several hundred dollars worth of raw materials.
Determine your needs.
It is better to buy a better (I.e. higher performance) boot than to buy the cheapest thing you can find. Usually, the hp boot will be more robust in both materials and construction, and should last longer. At the outset, ignore the price tags.
Even if you are a novice with no delusions of skiing grandeur, it is better to own your own boots and rent the skis. Ski boots are to be an effective exoskeleton to your foot and as such should be as personalized as possible.
Bells and whistles are largely a waste of money. With the exception of sliding cuff rivets, all you need on a boot are four buckles. The boot designs that have been the most successful over the years have a few things in common: they are simple, and they are shaped like a foot.
If last years boot looks like the current offering, other than the color, chances are it is the same. The latest and greatest might not be.
It is far easier to make a boot softer than it is to make it stiffer. Stiffer plastics transmit vibration better than soft plastics, thus snowfeel is improved. Generally, a stiffer plastic will last more ski days and degrade slower than a softer plastic. The ability to flex forward at the knees and ankles in order to ski effectively is grossly overrated. A large range of movement here is necessary when the geometric parameters of the boot are at odds with the skier’s body.
All plastics stiffen with negative temperature change, however, if it feels like a slipper in the shop, and you have only a vague notion of what is underfoot when you walk around, it won’t improve that much in the cold.
A stiffer boot will usually have a better quality liner. Think durability, feel, quality stitching and lasting (shape).
Before you go anywhere, trace the outline of your foot on a piece of card stock. Take this template with you as an aid in determining which product might work for you. Pick a boot in your approximate size, flip it over, and compare your template to the overall shape of the boot. If your foot is shaped like a hot dog, and the boot looks more like a watermelon, you won’t be happy. The converse is also true.
If the sales help offers ridicule rather than guidance, maybe you should shop elsewhere.
Assemble your options. Each manufacturer has a distinctive shell shape, though some are similar. Start with a boot that is one size smaller than your shoe size. If you wear your shoes loose, you should start even smaller. If one foot is slightly smaller than the other, use that one as the reference.
You can make a boot bigger, but you can’t make it smaller.
Boots are generally sized on the whole size, which means the primary difference between an 8 and 8.5 is the relative thickness of the liner, or the addition of a thin spacer under the liner inside the shell.
Pick a boot, and pull out the liner. This is sometimes tricky; you may want to ask for a little assistance. If you have a quality footbed, now is the time to pull it from its holster. Hopefully, it looks a little like this.
Slide the footbed into the shell (a supported foot will generally have a different volume profile than an unsupported foot). Carefully insert your bare foot in the shell. Picnic utensils are made out of plastic and can easily cut flesh.
While standing, lined up on the footbed, slide your foot forward in the shell until your longest toe makes light contact with the end of the toebox.
Flex forward slightly and look at the space behind your heel. One centimeter of space is good. This is not a race fit, it is a good fit.
Bear in mind that this is only an evaluation of the length.
Center the heel bone in the heel pocket. For those of you that care, the heel bone is also known as the Os Calcis or Calcaneous. Using the heelbone as a pivot, swing the forefoot from side to side and roughly determine how much space there is around the foot. Again, roughly one centimeter total, give or take a few millimeters.
Another consideration should be the overall contour from side to side. If the whole foot hits at the same time, on both sides; well then, bravo!
If you hit one little bony protrusion on either or both sides, make a note of it. If you hit plastic on both sides, (at the same time) take that boot off your list.
In this manner, find the boot that most resembles your foot.
Wearing a thin liner sock, like the liner made by the Smartwool Co, try on the selected liner. It will feel ridiculously tight, to the extent that you will think that I am out of my mind, sizing boots this way. Take a deep breath, remove your foot from the liner, and notice that the liner material is dense and not particularly stretchy on the outer surface.
Put the liner back in the shell, and against your better judgement, put your foot in the boot, making sure that your sock does not snag, doubling your toes. (That really hurts).
Buckle the boot, starting at the toes, moving upwards. Once buckled, unbuckle the lower two buckles and flex the boot to suck your heel back into the heel pocket. It may feel as though your foot has been swallowed by a large, constrictor-type, snake. Wait at least ten minutes before you take the boot off; as the liner foam warms up, it will become a bit more resilient. The size is okay if you suspect that you could maybe ski a run or two in it, and yet you are unsure. If the boot is comfortable at this point, it is the wrong size.
After a few minutes, there may be some loss of feeling due to lack of circulation. This is normal. Blood flows over the top of the foot, and this area may be compressed by the foam and plastic of the boot tongue. When you remove your foot from the boot, pull off the sock and look at the red areas over the top of the foot.
You may actually see areas swollen with blood that could not flow previously. If you were not able to close the lower part of the boot without severe pain or undue effort, take that boot off your list, as the instep clearance is likely insufficient. Similarly, if the boot began to feel somewhat gappy as the foam warmed to your foot, there may be too much instep clearance. Make a note of it.
Eliminate the boots that fall off the ends of the scale. Discounting a snug toe box, the boot you choose should feel like an extension of your body. If it feels clumsy (like a bucket stuck on your shoe) or like you accidentally stepped through a watermelon, it is probably not the right boot for you. If you feel like dancing, or want to go skiing immediately, then you have found your boot.
The previous information concerns boot/foot volume. There are other parameters to consider.
1. Ramp. The bootboard, or zeppa, hides under the liner.
Pull it out for a look-see. If it looks roughly like a foam doorstop, that is good. This type of bootboard is easy to cut down in order to tune toe/heel height. If the bootboard is made of molded plastic, it may not be possible to modify its geometry. If the bootboard is a thin plastic plate, you may wish to consider another boot.
The tilt of the bootboard is responsible for much of the pressure distribution along the length of the ski. Almost all boots have more heel height than necessary.
Too much heel height will cause a skier to sit back, tiring out the muscles of the thighs, and predisposing the skier to serious knee injuries. Heel height is specific to each individual, and is tunable to several thousandths of an inch.
If heel height is not properly tuned, the skier will have difficulty flexing and extending their legs without affecting the behavior of the ski. If you think that you are all set, stand in the boot shells, close your eyes, and relax. If you begin to sway back and forth, or fall onto your face, your ramp angle is not correct.
1a. Binding ramp. The contact points of the ski boot at toe and heel should be almost if not equal in measure from the base of the ski.
Most bindings are at least one-eighth of an inch taller at the heel than at the toe, with a few models taller still. The easiest way to remedy this relationship is to raise the toepiece with a spacer and longer screws. Alas, with the current emphasis on selling skis and bindings as an integrated system, this might not be possible. Try skiing on another pair of skis that can be leveled, and if it feels right, then buy a pair of skis and bindings that you can work with.
2. Forward lean. Calf/achilles clearance is another important parameter, in that it affects how much load the skier will take on their bones, and how much must be sustained by the muscles of the legs. Stand in the boots with the upper buckles flapping in the breeze. See how long it takes before you want to sit down or lean on something. If it feels like you want to straighten your legs, but you are impeded by the back of the boot cuff, there is a problem. Usually, the angle of the cuff at the shin is appropriate, but the contour at the back of the boot does not match the contour of the back of the leg. Straightening the cuff or jamming material into the tongue of the boot is not an adequate solution.
To effectively straighten the legs to a comfortable posture, the back of the boot needs to be re-contoured. Often this requires removing plastic or even cutting away the back of the cuff, replacing support with parts from a donor boot. This should be done only after establishing the correct ramp angle.
3. Cuff angle. The sole of each boot should be perpendicular to the column of support, without imposing a posture on the ankle joint. While walking in a straight line on a flat level surface, the soles of the boots should strike more or less flat. The floating rivets found on some boots are a means of adjusting cuff angle. If your boots do not have moveable rivets, you may be able to approximate the correct cuff angle by inserting shims between the liner and the cuff, on either side of the lower leg. Another alternative is to drill out the rivet and move the cuff, replacing the rivet with another suitable fastener.
At this point you may wish to seek professional assistance. Cuff alignment is not to be confused with canting, nor is it a suitable long term means of achieving “more edge”, or “less edge”.
4. Canting. Canting is not a means of increasing or decreasing the angle of incidence between the edge of the ski and the snow. Canting is not the alignment of the center of the knee mass over the big toe/second toe interspace. Canting is a means of restoring the mobility to the ankle joint when the skier is standing on one foot. Normally, the lateral movement of the center of mass compromises the mobility of the ankle joint by rolling it inside the boot.
With the proper use of angled shims, the ski is tilted, relaxing the ankle joint and allowing the skier to make subtle and intuitive movements of the foot. It is extremely rare that the thick side of the cant shim should be installed to the outside of the foot. If you have very straight legs, and narrow hips, and your bones stack well under compression, then you may not need to cant your skis. If you do not fit this profile, (and few do) canting may be worth considering. The advantages far outweigh the relatively minor inconvenience of having a dedicated right and left ski. If the skis are properly canted, the skier can effectively steer and countersteer the skis via the inversion/eversion of the foot, in a manner similar to manipulating a motorcycle. (A topic for further another time).