Blister Ski Boot Fitting Series

blog post series about fitting of ski boots

Notes

• Masterfit Instructor
• BootDoctors in Taos Ski Valley
• start with sizing
• communication with fitter
• try to quantify discomforts

• “It is okay if I touch your foot?”

• “Do you have any injuries or past surgeries I should know about?”

• “What does your athletic background look like?”

• “What types of shoes do you typically wear?”

• at least an hour for first session
• not “one and done”

• The ski boot is the number one reason that recreational skiers do not become diehard skiers, and the rental boot is the main culprit…

• replaces lots of boots bought online

• most important piece of gear

• measuring tool specifically for ski boots
• remove shoes and socks
• schemes: US, Euro, Mondopoint (“Mondo”)
• centimeters of the inside of the boot from heel to toe
• differs foot to foot
• personal preference
• instep measurement
• lots think they have high arch, really high instep

• trouble getting in and out of shoes like cowboy boots

• In ski boots, the fit over the instep is really important…

• comfortably snug

• Heel Instep Perimeter
• external Boot Sole Length includes length of heel and toe lugs

• stick to Mondo numbers

• no such thing has half-size shells
• most brands now only list full sizes
• half sizes just different removable insole thickness
• injection molds cost $100k+
• 8–9 shell sizes per model, 7–8 models per line
• difference of 5 mm
• pull liner out and put foot in shell
• move foot to front measure gap at heel with a dowel
  • 1″: roomy, “tourist” fit
  • ¾″: avid skier
  • ½″: expert, performance-focused

• Most new skiers and many experienced skiers don’t know what a “good” fitting boot feels like.

• Out of the box, a new boot should be suspiciously snug, like a firm handshake.

• firm, even pressure around the whole foot, from the metatarsals back to the heel, and up the lower leg. Only your toes should be able to move.

• When you first put the boot on, it should feel short.

• buckle up and bend ankle by driving knee forward
• more representative of active skiing position
• at least try one size smaller
• leave on for 10–15 minutes, flexing and making ski moves
• heel and ankle must feel locked
• liners will compress, “pack out” over time
• socks
  • “Thin to win.”
  • wicking materials, e.g. wool, synthetics
  • not cotton
  • keep baselayers and long johns out of boots
  • some sell ¾-length, some just cut theirs off
• foot volume

• take a metric tape measure and place one end on one corner of the heel cup, and pull the tape over the instep to the opposite corner of the heelcup

• This instep measurement should correspond to the length measurement of a “normal” foot.

• low insteps

  • you will just wind up stuffing a whole bunch of fit aids into the boot to secure the foot

  • first clue: have to crank buckles all the way down
  • try smaller size

  • a good boot fitter should always let you make the choice

• I often have customers come in and say, “I have a (insert brand name) foot.”

• was true five years back for Lange’s RL-11 (Banshee) shell

• It no longer holds true today.

• each company makes 3–4 different lasts
• heat moldable shells
• if customer wants to try particular model, don’t argue with them
• how is their dorsiflexion?
• get the boot they asked for, as well as your best guess, put one on one foot, the other on the other

• People ski for different reasons, and with different objectives.

• some just want an easy boot to put on

• Ski boots have gotten a lot better (more anatomical, more easily customizable, more diverse / varied, and so on).

• Of course, all those options also mean that it can be trickier to sift through it all…

• there’s no (currently publicly available) way to quantify or measure [flex] from brand to brand

• just positions within a brand’s lineup
• 130–150 top end, 70–90 softer, less expensive, less high-end
• stiffer for taller, larger, more aggressive
• either hypermobile or extremely rigid benefit from stiffer boots

• what most people hear about ski boots are bold claims about their features and performance

• fit is the main priority

• good bootfitters bring up custom insoles early on
• foundation
• address pronation or supination

• Without proper support, your foot is constantly elongating and collapsing within the boot. You also have voids beneath the foot…

• a relaxed foot is a happy foot

• insole materials should match rigidity and flexibility of foot

• In my opinion, everyone should be using a custom insole…

• ramp angle: angle of boot board (Zeppa), a few degrees drop from heel to toe, usu. 4–7°
• forward lean: angle of boot cuff, usu. 9–17°
• match angle of ankle joint to ski boot with a few leftover degrees
• balance fore-aft for even pressure on ball and heel
• rigid dorsiflexion common

  • skiing in the backseat

  • pressure on toes
  • shin bang
• heat molding usually used to create space, not take away
• traditional: stretching and grinding/punching
• Dremel
• race boots, plug boots: thicker plastic for grinding
• reducing volume
  • shim between liner and shell
  • some boots include shims
  • “volume reducers”
  • foam pads
    • L pads
    • C pads
    • butterfly wraps
  • pads pack out over time
  • can shift or move
  • look at aftermarket liners
• aftermarket liners
  • current liner packed out, want to reuse shell
  • looking for perfect fit
  • performance tuning
  • full foam-injected
    • Surefoot
    • Sidas
    • Pulse Boot Lab
    • leather and neoprene
    • injection ports throughout
    • proprietary PU blends
    • one-time process
    • the most “custom”
    • not everyone trained or equipped
    • for those who prefer stiffer interiors
  • partial foam-injected
    • Atomic Mimic Professional
    • quicker and simpler
    • V3 Tongue System for volumes
    • difference about 3mm
  • Heat-Moldable Foam
    • Intuition
    • heated to 120°C/250°F
    • built in LV (low volume), MV, HV
    • last longer than stock, but not as long as foam-injected
    • warmer, more insulative
    • lighter
  • Wrap v. tongue liners
    • most boots have hinged tongues
    • can help get snug around cuff
  • Cork
    • ZipFit
    • can modify after injection
    • don’t pack out the same as foam
    • rated for 1,000 ski days
    • absorb shock
    • not quite as efficient
    • stiffer than most sock liners
    • users tend to do “World Cup Entry” (foot into liner separately, then liner and foot into boot)
    • shoehorns
  • Power Straps
    • cuff is where lots of power transfer happens
    • cam-style buckles
    • elastic or static
    • Booster had patent on elastic
    • now expired
    • reduce shin bang
    • some use inside cuff, others outside
    • may have to drill out old rivets
• in 1980s, boot sole lengths were shorter

• The biggest problem with the boot fitting problem is that the boot often feels too short to the customer out of the box.

• Boot manufacturers started making their boots longer to try to mitigate the problem of constantly hearing, “this boot is too short.”

• rule of thumb: subtract 40mm for toe and heel lugs
• most helpful to know: boot sole length
• always stamped on heel lug

• get a custom footbed

• “Windlass action” of arch

• The more flexible your arch, the more supportive (or rigid) the foot bed will need to be. Conversely, the more rigid your arch, the more flexible (or shock absorbing) the foot bed should be.

• test: change in arch height when toes lifted
• can’t usually use orthotics in boots
• too large and thick
• “canting”

• relationship between the center of knee mass and the center of the foot in the frontal plane

• how far inward (medial) or outward (lateral) the knee is relative to the 2nd and 3rd toe

• modify sole to accommodate natural stance