Fitting Instructions

Before using a pair of Zipfit liners for the first time it’s highly recommended to do the initial fitting process as instructed below.

When the shells are heated sufficiently (~ 90°C) the heat from the shells transfers rapidly to the Zipfit liners, making the proprietary OneMinuteFit self-molding cork composite very maleable and makes the pre-filled OneMinuteFit ankle panels and tongue, take the shape of your feet and lower legs. The heat also thermally forms the side panels and the spoiler of the liners to take the internal shape of the shells, which greatly improves you control and precision over your skis by reinforcing and substantially increasing your edging and flexing support.

This unique feature of malleability is what make ZipFit liners a state of the art in inner boot design that guarantees incomparable support, insulation, unprecedented comfort, sensitivity, performance and above all, control.

Initial fitting process

  1. Remove the stock liners and boot boards (The part that lays in between the liner and the shell) from your boots.
  2. Heat shells to around 90°C  or 195°F.
  3. Insert footbeds into the Zipfit liners.
  4. Insert your feet into your Zipfit liners which are at room temperature or that have been on heating stacks for some some minutes.
  5. Pull strongly on the laces and lower the lace quick-lock to keep the liner on tight as this pushes the heal into the heal socket.
  6. Insert the end of the powerstrap into the metal loop and pull until snug. PRO TIP: Neatly the fold the extra lace cord in one hand and use the powerstrap velcro to hold the extra lace cord out of the way.
  7. Remove shells from the heat with some gloves that protect your hands from the heat.
  8. Re-install the boot boards.
  9. Insert you foot with the liner on into the shell with one swooping move by starting with inserting your toes into the boot and holding the back of the shell with a hand and your knee pointing forward, then pushing your heel down and into the shell. This is the ski racer move.
  10. Buckle normally.
  11. Take on a skiing stance. If you can go skiing.
  12. Wait until the liners cool.

HEATING OPTIONS for the initial fitting

  • Ski boot convection oven. Many ski shops have these kind of ovens as they are specifically designed to heat ski boot and other specialized footwear. They are perfect to do the initial fitting as it warms the shells consistently and are able to reach sufficient temperature rapidly. Support your ski shops and offer to pay for the use of their oven, beers are a welcomed extra. Also don’t forget to let the store manager how awesome ZipFit liners are and that they should stock them. (DO NOT use your kitchen oven, as temperatures can be inconsistent).
  • Boiling Water. The next best alternative for heating the ski boot shells, and the most common practice for those that don’t have a ski boot oven in their garage, is boiling water with large pot or a rice cooker. This is a tactic that many pro shops have been using now for 30 years. The use of boiling water is a quick and effective process that can be done at home, it is safe as the temperature is finite at around 100°C.
  • Heat stack. Heating the Zipfit inner boots on a common ski boot heat stack works, but it takes a long time for the hot air to penetrate the lining materials and soften the composite and the stacks of course do not heat the shells. Heat stacks in addition to warming the shells with one of the prior methods is also a great idea.


Rather than directly heating the liner, the paradigm Sven Coomer has been promoting for 30 years is to HEAT THE SHELL. This way the heat from the shells transfers into the liners effectively but gently, guaranteeing not to burn or damage the liner during the heating process. When the liner warms up liner materials, specially the OneMinuteFit cork composite, softens and enables the liner to adapt to both the shape your feet and the shells.

REPEAT THE HEAT before the first ski.

Ideally, after the initial fitting process it is best to go skiing so t. heat the shells once more just before you ski in your new Zipfits for the first time. That way, the OMFit composite in your Zipfits adapts perfectly to your personal anatomy and skiing dynamic. The liners will adapt within the first couple of runs (depending on how long the runs are).


To use the ZipFit liners without heating shells like described before will make the fit process to take much longer because you will be relying on body heat and dynamic activity. A cold Zipfit and shell can take a few days of skiing to adapt to your feet and provide maximum comfort and performance. That is why we strongly recommend you heat the shell for the initial fitting and for the first day of skiing in your new Zipfits. By heating them, there is no adaptation or adjustment period so they feel great from the first time you ski.


With Zipfit you can heat the shells and liners every day … the way the World Cup racers do … with a Hot Gear Bag.

With a Hot Gear Bag, both the liners and the shells are completely dry and even the stiffest shells are very easy to put on. The Hot Gear Bag is another Zipfit invention to help people with very stiff and difficult-to-put-on shells. You can heat fit the shells (and Zipfit) every day for the best comfort and support with a Hot Gear Bag. This also activates the constant dynamic molding process of your Zipfit liners. The Hot Gear Bag allows you to use your Zipfit inner boot with any other boot shell – Nordic, alpine touring or alpine.

The Hot Gear Bag is considered to be an essential piece of every skier’s equipment.

Fitting Tips and Tricks


While holding down the back of the shell step the other foot forward and genuflex your knee down to the floor. This motion spreads the shells stiff flaps and lifts the heel painlessly and effortlessly out of the shell. Be sure and leave your Zipfit fastened and on your foot during this process.

To put your Zipfit liner back in the boot, either heat the shell and/or use a friend to help open a room temperature shell.

Always “hoist” the liner to seat the heel under the heel huggers every day.

Racers and other experts have been going in and out of their boots this way for decades … because of the stiff shells. Now the best boot models all have stiff shells, especially after skiing, and getting out the old fashioned way can cut and badly bruise your instep skin and bones.

Many times skiers get stuck, painfully, half-way-in and half-way-out when they try and take their foot out of the liner and the boot at the same time. Pulling the feet out of the liners and the shell deforms the lining materials and shortens their lifespan.


Best practice is to reheat your SKI BOOT SHELLS to start each season, because at the beginning of each season, after a summer of soft shoes, your feet are not used to ski boots. They have the early season blues. By heating the shells again and inserting the liners to wear around, or better still just arranging to start the first day in HOT-shells, you will automatically avert much of the pain that comes with the early season black and blues. You will be set for the rest of the season.

More Tips in FAQ

Once the initial fitting has been done the beauty of ZIPFIT liners are that they dynamically adjust to the changing shape of your foot and lower leg. Every time the OneMinuteFit self-molding cork composite is warmed it becomes malleable and easily takes the shape of your foot and lower leg. Just placing your a ski boots and ZIPFIT liners in a warm and dry place or placing them in a Hot Gear Bag the night before going skiing makes them able to adjust to your feet and lower legs, ensuring a comfortable and precise fit.