Ski Boots

Ski boot flex, canting and inner boot – what can my ski boot do?

Your ski boot should provide stability on the ski, support and secure the foot as well as possible in case of a crash and guarantee great power transfer. Also, you want your boot to be flexible, you want to be able to walk with it (or do some après ski) and have them easy to handle. The different models all have their own characteristics and skills, be it on-piste, freeride/tour, allmountain, freestyle or racing boots.

The most known characteristic of a ski boot is its flex. Pretty often, you will hear someone on the lifts or huts telling how great they are because of their high flex of 130. But what does that even mean? This measure refers to the stiffness of your stem forwards. The higher the flex, the less will the stem move. This ensures more stability in the boot. However, it is really important that the boot will properly transmit your movement impulses. If the flex is too high, this will lead to too much resistance or hinder your ankles from moving properly. As of this, a higher flex also asks for more strength, which is why women’s boots usually have a slightly lower flex, as do children’s boots, starting at 50. However, the flex is not a normed measure. This means, that if you were to compare different boots by different manufacturers, this might be misleading!

Another characteristic is the isolation of the boot. Allmountain boots for example are more isolated and more comfortable than a race boot. But the thicker the isolation, the softer the boot, leading to a dampening of your power transfer.

The different boots also have other functions. Some have adjustable canting. This means, that the angle between stem and sole can be adapted, making the neutralization of knock knees and bandy legs possible to reach a neutral position. Also, most ski boots will let you change the inner sole and put your own ones in. Also, many are compatible with different forms of heating elements or even have heaters built into them, keeping your feet warm even on the coldest days!

Alpine boots are generally built to fit alpine skis and alpine bindings. Most of them can also be used on touring frame bindings and some even have pin inserts to make them fit tec-bindings. This is especially interesting to those who spend much time in the off-piste and want to do some ascents as well.

Men’s vs. Women’s ski boots: Men’s and women’s ski boots are not only different in their flex. They also differ in their construction. Because a woman’s body is simply a bit different than a man’s body, which is why the boot needs to be different as well. Since women’s calves start lower, the stem of the boot is lower as well, about 4cm. Also, the inner boot is cut more narrow and the heel is more narrow.  

The different usage areas of apline ski boots

On-Piste boots: Their area to be: The slopes. And most of the times, these are groomed, great for carving, long and short turns, slow and fast. As of this, the boot will be less dampened than allmountain boots, still they will be more comfortable than race ski boots. Their flex varies quite a lot and should be chosen based on skills and weight.

Allmountain boots: As the name already tells, and as we already know from allmountain skis, this ski boot is very diverse in its abilities. A compromise between comfort and performance is found. The inner boot is rather comfortable while the shell is still pretty hard. As of this, the boot will have a relatively high flex, making them great for sporty turns on the slopes as well as off-piste tours and moguls.

Freeride and touring boots: This boot has a rather low flex, which is why it is a bit softer, offering more movement and flexibility and a dampened shell. Because when skiing in the off-piste, the snow will often be harsh and not always powdery, which is why your body will have to go through some hits and harsh impacts, and this should be dampened as well as possible to preserve your bones and joints. The inner boot is more cushioned and the stem oftentimes a bit lower. This boot is also great for moguls!

Race boot: Great transfer of power and awesome stability – that is what you want from your racing boot. And this is achieved by having a very stiff shell and a thin inner boot. This ski boot, having the highest flex of them all at 120 or 130, for women at around 110, lets you go the highest speeds on the slopes, speed through the slalom poles and really put some high pressure on your edges. But this ski is not really the most comfortable one, but really – who wants comfort when you can have speed instead? The boot also has the groin most narrow. And because most feet will not perfectly fit the boot, a boot fitting is for sure advisable!

Freestyle ski boot: Jumping over those kickers, doing a rough landing, getting some serious hits in uneven terrain and doing rails – this boot for sure needs to stand quite some tough things. It also needs to make sure your feet live through all this. As of this, park & pipe boots have a dampening shell, offer more flexibility due to a lower flex. But of course, this boot needs to fit perfectly and should not be too large, because who would want to drop down a 10m jump and be shaking in the boot when landing?

Read more regarding ski boots

- Telemark and alpine ski boot: Sole length and mondopoint

- How to choose the right ski length?