Choosing the Best Boot

Here is the simplest, fastest and most accurate procedure to find the best ski boot model for you. This system works for selecting new or used ski boots.

The Ski Boot Shell shape is critical to an excellent fit and the best performance. Sven Coomer, the founder of ZipFit, with more than 40 years in the industry, describes the mechanics of finding the optimal shell.

1st. Orthotics: Choose your underfoot support. A high-quality foot bed or orthotics will help to stabilize your foot by bringing the sole of the boot up to your foot and raising your foot into the wider part of the shell. It also helps you determine the best size Zipfit for your shells.

2nd. Shell sizing: To estimate your shell size, choose 2-3 preferred models. Extract the liner. Place your orthotics in the bottom. Slide your foot into the empty shell. Stand up with your toes just barely touching the front of the toe box. The correct shell size will show a clearance of 10 to 15mm all around your heel radius. This allows about 5-6mm for the liner's insulation-padding.


  • It's dark in there, use pen-lite or a 10-15mm dowel to feel around the heel for clearance.
  • Stand up: Standing takes into consideration your foot's peculiar mechanics.
  • Try on different ski boot models: Between the brands and their models, the shell volumes, widths and sizes vary considerably.
  • The "shell" size can be found embossed inside the top of the shell flap overlap, (not the cuff).
  • The external boot sole length is for adjusting your boot to the ski bindings and can vary between brands, it does not relate to foot size.

3rd. Width: During shell sizing note if your toes, forefoot or fleshy outsides of your feet are touching the shell's sides. If you feel squeezed from the sides, find another model. It is important to choose a model with sufficient width at the correct length.


  • Gauge the width correctly: The width of you ski boot shell must accommodate your foot when it is raised up by your footbed and Zipfit inner boot's sole thickness (4-6mm). Overall, you can expect be elevated about 10mm into a wider part of the boot shell.
  • Gauge the volume correctly: It is important to select a boot that matches the volume and width of your ankles. Boots that are too high in volume exceed more than 10 mm on each side of the ankles.

4th. Boot size versus liner size: Do not bother trying on the liner alone like a slipper. Factory liners are invariably short for the shells by as much as one half to a full size. Too often skiers fit and buy according to the liner size and end up with a shell size that is too large for their feet. Differences in liners can vary more than the shells and distract you from choosing the best shell model.

It is extremely important to find the right shell size. Use one liner (a Zipfit Inner Boot or a well-used liner from an old pair of boots) while trying on different shells.

Socks? Very thin ... or no socks at all. Or better still a plastic sock allows the foot to slip frictionless into the WARMED Zipfit lining ... and to position the heel easily and deeply into the heel pocket, under the heel huggers.

5th. Choosing a Zipfit: Preferably the thinnest of them all - because you will use the same liner (and foot bed) to make a final decision on which is the best shell model for your feet.

6th. Compare shell models: Do so by wearing a different model on each foot. You will be able to detect the physical and visceral differences immediately. Note the differences in the way each shell model surrounds and supports your foot. The differences can be like comparing rubber boots and track shoes.

Be sure and wear the same Zipfit model and orthotics as you try on different models. This way you are truly comparing shells, and not differences between liners.

TIP: Ask the shop to heat the different shells before you try them on. This makes Zipfit (or any liner, for that matter) adapt more quickly to the shell. Remember, your using liners that are already adapted to your feet.

A good boot fitter can guide you, swap the liners between warmed shells, insert the liners without wrinkling, show you how to "pump" the liners, seat your heel and then adjust the closures . . . but he cannot tell which model "feels and fits" the best. Your feet will tell you what's best.

If you try on 3 or four shell models you should be satisfied within 30 minutes. Your decision will be rational. You will know you have the best boot for your feet.