02 Volume Matching

The Springtime Blues

Comfort almost always sells boots.  Fit and performance?  Seldom.  The unfortunate reality of retail is that most skiers leave the shop with too much boot.  Generally, about one size too much.  This, despite the efforts of well-meaning sales staff that may (or may not) know all too well what is going on.

When you put your foot in a boot of the correct size, blood should rush to your face from pedal constriction.  Few in their right mind would associate that physical response with what will soon become a comfortable, supportive boot.

In retail, it is easy to simply let the customer buy the boot in the size of their choosing, and think later on that the liners have simply, ‘packed out’.  Never mind that a liner in the correct shell will last almost as long as the shell without significant loosening.  Properly fit boots may wear out, but they don’t pack out. Good liners will passively form to your foot over time, but not to the point of feeling ‘loose’.


Make life easy for yourself: Start with a boot that bears at least some semblance to your own foot.  With your bare foot centered in the empty shell, you should have about 5mm around the periphery.

If the fit is close to usable, ski a bit to determine where the boot needs to be altered.  Many shortcomings not apparent at the point of sale will be revealed on the snow.  If your toes go numb, or you feel pressure points, simply strip off your socks when you get inside, and look for the red blotches, and/or imprints from the weave of your socks.  Mark these with a ballpoint pen or Sharpie, using the color of your preference.

If contouring is needed in the ankle/heel area, the ‘ramp angle’ of the boot board (Zeppa) should be addressed first, as this may change the location of that joint relative to the shell.

(Note you may require different right and left ramps for snowboarding hardboots,  and these numbers may be quite different then for your alpine or telemark boots.)

NB, most ramps are a bit on the high side.


Foot support

In many cases, the initial fit of the shell will be affected to the positive once the foot is supported.  Foot support may then obviate the need for shell modifications.  A good example is Navicular protrusion. (commonly referred to as a ‘second’ medial ankle bone.

So, if you wish to extract the maximum of performance and comfort from your boots, you should start by supporting your foot with a proper footbed.

Footbed discussion

Volumetric considerations.

Done well, boot fitting should be considered a reductive process, which is to say; you remove material rather than adding it. Or, you make space rather than filling space. In general, if you need to add much padding to a liner to ensure fit, the boot is the wrong size or shape for the foot. In the event that you have no other option, make certain that additional padding does not cross either the Achilles or the Tibialis Anticus (the prominent band at the front of the ankle structure) tendons.

The shell game.

The options for altering shell volume are threefold:  you can trim the liner, expand the shell with heat and pressure, or grind the shell.  Sometimes all three methods will be used at the same location.

Generally speaking, if the bare foot is hitting plastic with no liner, the shell should be ‘punched’.  If the foot feels constricted, but the liner is thin, and there is no foot /shell contact otherwise, then a bit of grinding may solve the problem.  If the spatial need is only 1 or 2mm, grinding is fast and viable.  Any more than that, and the integrity of the shell may be compromised.  Nothing like a cracked shell in spring runoff…

Instep clearance can be gained by thinning the plastic shell of the tongue, and by removing some of the ‘extra’ largely cosmetic layers of the liner in that area.  Some liners are more suited than others to cutting.


One should not need a cheater bar in order to buckle in.  If the geometry is correct, and the size is right, buckle tension should be even, solid, and consistent.  Buckles are there to close the shell, not to restrain your foot.

If the boot fits well, you should be able to ski effectively at slow speeds with boots unbuckled.  I will often make a few turns at the start of my first run of the day with my boots loose.