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Liner Notes


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Aftermarket liners can give your boots — and aching feet — a whole new life.

Do you have impossible-to-fit feet? Are you loath to let go of your beloved old ski boots, even though the liners are completely packed out? Maybe you’ve already invested a chunk of change in having your boot soles ground to correct an alignment problem. Any of these scenarios should make you consider an aftermarket boot liner, which replaces the liner that comes with your boots and, through a variety of fitting methods, can improve fit, comfort, and performance — and also extend the life of a boot.

Stock liners are designed, for economies of scale, to feel at least somewhat comfortable on a lot of people’s feet. To raise the overall comfort level, some companies now include semiconformable liners in high-end boots, but even these don’t compare to the total customization of an aftermarket liner. “There is some biomechanical incompatibility with most skiers in most ski boots,” says Scott Russo of Dalbello, distributor of Zipfit custom liners. A custom-fit liner “works more with the natural anatomy of your foot and lower leg,” says Russo. “A lot of midlevel skiers will find their performance improves simply because they’re skiing in a more natural state.”

Other advantages? Higher-quality materials mean aftermarket liners won’t pack out like many standard liners, so you can dispense with cranking down your buckles. You can even rev-up the performance of an average boot shell with a stiffer liner (like ZipFit’s Sidewinder).

Which liner to pick depends on what fitting method appeals to you most.

Conform’able liners ($160-$195) are injected with foam — through octopuslike tubes — from the heel to the ball of the foot and, in the higher-priced model, into the tongue. The resultant svelte fit is particularly effective for small, narrow feet, says boot specialist Matt Ross of Surefoot in Aspen. The drawback is that once the foam is in, it can’t be altered, so the process must be done right the first time. Visiting a reputable boot fitter is a must.

Thermoflex liners ($185) from Raichle are made of EVA and polyolefin, a heat-moldable material that also keeps your tootsies toasty. A ski shop warms the liners to make them soft and pliable; then you stand in them, and in 15 minutes the liners mold to the contours of your feet and boots. Assorted fitting aids can be inserted during the process (e.g., a cap to make the toe box bigger), and the liners can be remolded several times to dial in fit. If you’re into backcountry touring, you’ll appreciate the Thermoflex’s featherlight weight (up to a pound less than standard liners).

ZipFit ($179-$249), the original aftermarket liner, is now filled with a mixture of silicone and cork. These materials turn viscous when heated in a shop’s microwave and displace around your foot, flowing from high-pressure areas to low-pressure ones to assure a uniform fit. The liner can be reheated and remolded as necessary; additional silicone and cork can also be injected.


Distributed by Salomon, 800-654-2668,

Raichle Thermoflex
Distributed by Life-Link, 800-443-8620,

Distributed by Dalbello Sports, 800-775-8100,