The stock liners that come in most ski boots last about 60 ski days- about 4-5 seasons for the average skier. Unless you walk a lot in your boots, the shells should last considerably longer.

In order to sell a large quantity of boots, manufacturers use materials that can adapt to as many foot types as possible- this usually means soft felt and open-cell foam. Consequently, liners break down long before the shells, leading to fit problems.
By now, most skiers know about the benefits of custom-molded insoles, but few have tuned in to the custom liner as a bootfitting solution. We stock two types: Zipfit self-molding liners and Conformable foam-injected liners.

Many racers are already familiar with foam-injected liners as a performance upgrade. In this system, a sturdy liner containing hollow internal chambers is molded by injecting the chambers with two chemicals, while you wear the liner in the shell. The chemical combination reacts and expands into a stiff foam-like material, introducing a lot of pressure around the foot and creating a firm-fitting custom mold of your foot and lower leg.

Although injected liners are typically an option chosen for their amazing sensitivity and power transmission, they also can be real problem solvers. For challenging foot shapes, the Conformable’s molding properties can be an excellent alternative to extensive boot and liner modification.

These liners do have limited capability to be moved from shell to shell, because they’re molded on both sides- to the shape of the shell, as well as your foot (you can usually transfer them to a similar shell from the same brand). Injected liners require an orthotic footbed, and a time- and labor-intensive process that includes a multi-day break-in period.

Zipfit liners are a newer, comfier alternative, designed by boot genius at large, Sven Coomer, the founder of Footloose. The liner is made of extra-durable materials, and filled with a viscous oil that contains chips of cork. This thick fluid molds around your foot, adjusting on its own, by body heat and pressure transmitted through the boot as you ski.

This material is an ideal medium for the application- it remains malleable (unlike a foam liner) so that as temperatures and boot shells change, the liner just needs to be skied to be re-customized. It doesn’t compress like the open-cell foam used in stock liners, so with proper care Zipfits will easily last for hundreds of ski days. We have local patrollers, instructors, and shop employees (150+ days/year skiers) who’ve been skiing these liners for multiple seasons- and they’re still going strong.

Zipfits are not only stiffer and far more supportive than stock liners, their self-molding property fills more of the voids between your foot and the boot shell, improving precision. Zipfit liners fit in any conventional ski boot (and can be easily transferred from shell to shell), but they do require a custom footbed like the Superfeet Kork.

Either way, if your liners are shot (and the shells are not), or it’s time to take your bootfit to the next level, it’s worth checking out the custom liner option.