Parts of a Ski Boot – Labeled Shell, Cuff and Liner

All 10 parts on the diagram

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The boot 7

Shell Rigid, so a push from the leg goes straight to the ski. The soft liner sits inside it.
Cuff It is joined to the shell at the ankle. That lets the two move a little apart. A number on it often gives the flex, from soft to stiff.
Buckles Two close the shell over the foot. Two close the cuff round the leg. On many boots the buckle turns to make small changes to the fit.
Power strap A hook-and-loop strap above the top buckle. It works like one more buckle, closing the gap between the leg and the boot.
Sole Its toe and heel ledges are made to a standard shape. The binding on the ski can then grip the boot at both ends.
Cuff pivot There is one on each side. They are the pivot points that let the cuff and the shell move independently.
Walk mode lever It frees the cuff from the shell. The ankle can then bend for walking. Flipped back down, it locks the two together for skiing.

Liner and footbed 3

Liner It pads the foot and keeps it warm inside the hard shell. It packs down and takes the shape of the foot with use.
Tongue The shin presses on it when the skier leans forward. On three-piece boots a separate plastic tongue closes the front of the shell.
Footbed It can be lifted out. Some are trimmed to length from a ready-made shape and some are molded to one skier's foot.

How this list was compiled: Part names checked on 2026-09-30, a name kept only when two of these use it for the part. (1) Wikipedia, text only: Ski boot (shell, cuff, buckles, power strap, tongue, rigid sole with toe and heel flanges, the rivets that form the pivot points). (2) REI Expert Advice, How to Choose Ski Boots, https://www.rei.com/learn/expert-advice/alpine-ski-boots.html, read in the Internet Archive copy (shell, cuff, buckles, liners, tongue, insoles or footbeds, sole, walk mode lever on the back spine). (3) evo, How to Choose Ski Boots: Size, Fit and Flex, https://www.evo.com/guides/how-to-choose-and-size-ski-boots, read in the Internet Archive copy (shell, cuff, liner, footbed, power strap, micro-adjustable buckles, walk mode, cuff rivets, flex index on the cuff). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry, a composite of no one make; nothing traced. Licence: own work

How it works

A ski boot joins the skier to the ski: its rigid sole clips into the binding at the toe and the heel. These two drawings name 10 parts, on the hard outer boot and on the soft liner inside it.

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Outside: shell, cuff and closures

The first drawing is an alpine boot from the side, toe to the right. The hard plastic shell holds the foot and the cuff holds the lower leg; they are riveted together at the ankle. Buckles close the openings over the foot and up the front of the leg, and the power strap round the top works like one more buckle.

Inside: liner, tongue and footbed

The second drawing is the liner out of the shell. It is the soft, removable inner boot, with a padded tongue down the front. The footbed beside it lies flat inside the liner, under the foot.

A walk mode lever frees the cuff for walking; flip it back down before skiing.
The number on the cuff is the flex: a higher number means a stiffer boot, but makers do not measure it the same way.

Questions and answers

What are the parts of a ski boot called?

Outside: the shell round the foot, the cuff round the leg, the buckles, the power strap and the sole. Inside: the liner with its tongue, and the footbed under the foot. Some boots add a walk mode lever on the back.

What is the difference between the shell and the liner?

The shell is the hard plastic outer boot, which passes the skier's movements to the ski. The liner is the soft inner boot that lifts out; it pads and insulates the foot inside the rigid shell.

What is the strap at the top of a ski boot for?

It is the power strap. It sits above the top buckle and acts as one more buckle, closing the gap between the leg and the boot.

What is a footbed in a ski boot?

The insole inside the liner, the platform the foot rests on. Most stock footbeds do little to support the contours of the foot; others are trimmed to length or custom molded to one foot.