K2 Spyre 100 Heat

Model Year
All-Mountain Traditional
Last Width
Flex Index
Price (MSRP)

The Gist

Testers who are familiar of the K2 medium-widths of the past said that the 2018 Spyre 100 Heat had the best initial fit they've ever experienced. New this year throughout the K2 boot line are revised liners with a more open toebox, a tighter heel and ankle and a pre-pressed navicular area. All these elements received a thumbs-up from our test team on this one.

The Fit

Our team felt the Spyre 100 Heat nailed the medium-width fit target, dead on, with the mention that this runs a bit roomy in the toebox, forefoot and instep. This is good news for those with high arches! With the Power Wedge rear spoiler installed some testers felt the stance a bit forward and jabby on the calf—with it removed it was slightly upright and more open in fit. Custom tests showed positive comfort changes when the Intuition liner was fully heat molded.


Tried-and-true, steady-eddie, workhorse—pick your descriptor for reliable and capable and insert it here. Testers found the regular roll onto an edge supremely bankable, maybe to a fault as a few mentioned it perhaps lacked a little spark and energy in transitions. They liked the solid 100 flex for its fore-aft support and comfortable contact with the shin while skiing.

Cool Features

Testers were stoked on the new heated Thermic liner—simple to operate buttons and they said it warmed up quickly. The Heat model is a $150 premium at full-pop retail, but our testers thought it well worth it. The dual cuff adjustment mechanism offers maximum stance alignment modification, and GripWalk outsoles (rockered, for use with GripWalk bindings) are available as an optional purchase.

Sizes (MP) 
Hike Mode 
Heat Moldable Liner 
Boot width profile 
Also in this Collection 
Cantology Compatible 
Total Avg Score 
  • 2017-18 K2 Spyre 100 Heat at America's Best Bootfitters Boot Test
  • 2017-18 K2 Spyre 100 Heat at America's Best Bootfitters Boot Test
  • 2017-18 K2 Spyre 100 Heat at America's Best Bootfitters Boot Test


  • “More comfortable than in past years.” -- Danielle Goldsmith
  • “Wider, cold feet? This boot's for you!” -- Michael Kendrick Powderly
  • “Very supportive—skis strong and excels at arcing.” -- Megen Johnson
  • “The built-in heater is the best ever—the way of the future!” -- Linda Parazoo
  • “The heater and plush liner are nice additions for all day comfort.” -- Kelly Finnen
  • “This boot is for the woman who hates ski boots—high scores for comfort and a heater!” -- Amy Post
  • “Lay it over! Strong and solid! Where you going, foot? Nowhere!” -- Emily Poore
  • “Heat equals happy toes!” -- Catherina Simones
  • “This boot fits the category perfectly—all over the mountain for all shapes of feet.” -- Sam Tischendorf
  • “The heat feature is awesome! Solid boot—I would totally ski this boot all day!” -- Melodie Buell


  • “You'd better not have cankles.” -- Linda Parazoo
  • “Felt kind of boxy and heavy.” -- Deb Mjelde
  • “Almost too strong, like a power lifter—a tad bound-up.” -- Megen Johnson
  • “Extra space in the lower boot made for longer response time.” -- Catherina Simones

This boot available at...

Seattle, WA
Warren, VT
Taos Ski Valley, NM
Telluride, CO
Telluride, CO
Ellicottville, NY

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