A Very Deep Dive on Ski Boots, Part 4: Liners, Ramp Angle, & Forward Lean (Ep.88)



TOPICS & TIMES:

  • Grilamid; Polyamide (PA); Polypropylene (PP) (6:18)
  • Forward Lean (14:06)
  • Ramp Angles (24:33)
  • World Cup ski racers are weird (28:06)
  • Forward Lean: what should skiers look for? (31:58)
  • The 20/21 Hawx Ultra “S” (38:00)
  • Ski Boot Liners (42:38)
  • The “First Fit” Battle (46:13)
  • Comfort vs Performance (48:13)
  • Foam-injected Liners (57:45)
  • EVA (“Layered Foam”) Liners (1:06:04)
  • 3D Liners (1:08:02)
  • Atomic’s “Mimic” liner technology (1:09:14)
  • How often can Mimic liners be reshaped? (1:17:14)
  • Aftermarket Liners? (1:19:47)
  • The new Hawx Prime XTD boot (1:27:03)

Ski boot liners are probably the most overlooked and least appreciated piece of ski gear out there, but they are a critical piece of equipment. So Matt Manser, the product manager of Atomic Ski Boots, is back to demystify the extremely complex, very expensive, and poorly understood category of ski boot liners.

We kick off the conversation by brushing up a bit on plastics (specifically, we discuss the not-so-straightforward label, “Grilamid”); then we go a bit deeper into the topics of forward lean and ramp angles; and then we jump down the rabbit hole on ski boot liners, and talk about the different types of liners and the pros and cons of each of them; the “30 seconds” test and why Atomic views it as so critical; whether it’s smart to shove an aftermarket liner into a high-performance shell; and then Matt talks about a brand new liner from Atomic that incorporates their “Mimic” technology.

Along the way, we also talk about next year’s Hawx Ultra 130 S alpine boot, and the also-new-for-next-year Hawx Prime XTD.

OTHER EPISODES IN THIS SERIES:

Atomic's Matt Manser goes on Blister's GEAR:30 Podcast to discuss the new Atomic Hawx Prime XTD boot, Atomic's new Mimic Liners, Forward Lean, Ramp Angle, & More
Atomic Hawx Prime XTD 130
Atomic's Matt Manser goes on Blister's GEAR:30 Podcast to discuss the new Atomic Hawx Prime XTD boot, Atomic's new Mimic Liners, Forward Lean, Ramp Angle, & More
Atomic Hawx Prime XTD 130 — Mimic Liner

44 comments on “A Very Deep Dive on Ski Boots, Part 4: Liners, Ramp Angle, & Forward Lean (Ep.88)”

  1. I really wish Atomic had launched the “Prime” version as part of the v1 XTD 130 (especially since the Primes are so popular), but at the same time I’ve learned to expect that custom boot fitting is part of the process, especially for a dude with a 6th toe and super high arch. I’ve hacked the crap out of my XTD 130s by heat molding the things twice, punched ’em, have custom foot beds, and replaced the boot board with only a heal pad (which totally works even though everyone thinks I’m crazy for doing that).

    Once you know the boot length you are, buy the boot with the features you want and make it fit vs trying to buy something that feels good out of the box. It’s ridiculous how many people are skiing in boots that are too big. I made this mistake once, and nothing has had a worse impact on my skiing experience than skiing in poor fitting or sloppy big boots.

    Love these technical deep dive’s keep them coming. Would love to hear one from one of the three piece boot manufacturers.

    • Very low ceiling in that xtd. Theoretically, the plastic stretches upward in the heat mold, but I’ve found that boot problematic for high arches. A great boot for certain high arches is the Fischer Ranger Free, but only works for very skinny calves.

      • Hey TreeStashes, that’s why the new Hawx Prime XTD will be such a great solution for medium feet (out of the box) and medium-high volume feet (after heat molding). Cheers

        • It might work! And of course, going to a great bootfitter is always the best call. I’ve seen a good number of high-arch / small heel feet, which might not work well in a medium volume boot.

        • Hey Matt – one more question for you. I’ve been messing around with Intuition tour wrap liners in the XTD. Worth noting that an Intuition liner will save 100-200g over the stock liner, and will ski much, much better. One thing I’ve noticed now that I’ve got my ankle locked in with dense foam: it seems like the heel cup distorts, at least on dry ground if not alpine conditions. Does Atomic have a position on aftermarket liners? It could be simply that the depth and articulation of the heel cup is a bit much on my foot, which has a decently straight drop from the Achilles tendon down to the calcaneus. Thanks for any thoughts.

  2. If you ever break down footage of World Cup level racers, it’s amazing how far forward they start and then how much further they flex the boot.

    They have greater dorsiflexion than most of us, and they don’t have to last very long in that stance. The longest run on the WC (Wengen DH) is ~2:30, and most tech event runs are over in a little over a minute.

  3. Trying to reinforce something that Matt said: Evaluations like the dorsiflexion test that Matt suggested (putting your toes against the wall and driving your knee to contact without lifting your heel) tell you if you can use higher lean angles, but they don’t tell you if you should.

    For example, I can stand with my toe >4″ back from the wall and drive my knee to the wall while keeping the majority of my weight on my heel (not just keeping it down, but actively weighting it). In theory this means I can use a pretty crazy amount of lean. If I actually did that my ski days would be about two runs long, though (which, not coincidentally, is exactly the duration of a World Cup GS or SL). Freeskiing in a perpetual low crouch like that is exhausting, and when you get tired and try to “stand up” to relieve your legs and core you can find yourself too far forward on the ski.

    IMO that’s the real tradeoff for many of us: It’s a choice between getting low and athletic for aggressive skiing with “sharp knees and ankles”, or higher and more skeletally aligned for all-day endurance. As Matt keeps saying there’s no right answer here. Horses for courses, etc.

  4. What about cork liners and cork flow liners in particular. My understanding is that OEM cork flow liners were fairly common in high end consumer boots at one time. Others than a few race boots these seem to be a rarity nowadays. People seem to rave about Zipfits. Why isn’t this technology more used more ?

    • It doesn’t do so well with that “30 second test”. Cork liners (actually bits of cork in a viscous resin) take some time to flow around the foot. Generally the initial fit process with a Zip is to heat and thoroughly knead the liner, then insert foot+liner into shell and let it flow. The fit before you do that can be a bit rough.

      The big advantage of cork is that the liner continues to flow and adapt to foot/equipment changes very slowly over time, and (in the case of the Zip) can be adjusted by adding/removing cork.

      I have the Head Raptor 140 RS, which is well-reviewed on Blister and has cork ankle pockets. That’s not a boot from which people expect a “30-second fit”, though, as it’s basically one step down from a racing plug.

    • Hi Rome, Atomic used to use cork oil in our World Cup-level liners about 10 years ago but since cork oil is after all a fluid, the cork oil would settle when not in use and people would have to constantly adjust their liners to get them to fit right or fit like they did before. So, we’ve been using other solutions like Mimic, to attain the ideal fit.

    • Cutting costs is the main reason, even on fairly high end boots this days you get crappy liners that are clapped out by the end of a season, zipfits are fantastic liners but they do cost more than many boots!

  5. Drinking the Kool-aid there Jonathon. The compromises in skiing performance required to achieve optimum shop fit (utilizing low density foams and lack of customization), are just compromizes driven by an unsophisticated market. Hard outer layers are unnecessary to a liner, regardless if mold-able (as per mimic) or not, and are just catering to traditional manufacturing techniques and customer expectations. OME Intuition liners do come pre-molded, Sidas and Palau liners are not (quality of foam, undue emphasis on shop fit) comparable to Intuition’s high end models, and Mat’s characterization of Intuitions as thick and high volume and just multiple layers of foam is simplistic (given they have 29 models, and multiple volumes) and self serving. Skiing performance and long term consistency of fit is almost always (a few high end race boot liners are pretty sweet, if they fit) going to optimized by replacing stock liners with high density, custom sized (obviously length but also volume) and custom molded liners. I’ve had consistently positive experience with Intuitions (fitted and molded at their Vancouver headquarters), but I’ve also used and appreciated Zipfit and Sidas injection foam liners in the past, however they’re expensive and the results unusually sensitive to the (wildly varying) expertise of the boot fitter.

    • Being courteous to your interviewee isn’t “drinking the Kool-aid”.

      I mean, if he went “full pro-wrestling” and whacked them over the head with a folding chair every time they said something that looked like it might be self-serving, then there wouldn’t be too many more guests for the podcast.

      Also I really don’t see a problem with people who’ve poured a couple years of their careers into a product like that taking some pride in their work. It’s not like you have to buy it.

  6. Now I know who onenerdykid is, it now makes sense why you were one of the most knowledgeable contributors on otherwise painful but entertaining forums on newschoolers.

    You sure actual intuition liners are layered? I know all the ones that come stock in Scarpas, Full Tilts and (perviously) Dalbellos (to name a few) that are made with ultralon and have an ‘intuition’ tag were/are layered. Even those boot makers top “pro” liners were/are far from an actual intuition in terms of performance and fit.

    I was sure that their high density liners like the alpine HD and the power wrap (other than the wrap part) were just cuts from a single density of that foam?

    The Mimic liner will be available for sale on it’s own (I don’t have to buy a boot to get it) and in certain boots? I only listened once but I seem to have understood it that way. If yes, any idea on MSRP for just the liner that can be disclosed at this time?

    And also, Patrickchase posted above about the upright stance being less fatiguing. Actually, Patrick’s post read like marketing copy but there must be some truth to it when it comes to rockered skis (again per the marketing). If you have no tip to drive why not just stand upright and lean side to side to turn? It’s not my bag but it seems to make sense.

    • Hi Flim, in addition to being available in complete boots, Mimic Liners (for both men & women) will be available separately for Hawx Ultra, Hawx Ultra XTD, Hawx Prime, and Hawx Prime XTD. So if you already have a Hawx Ultra, you can just get a Mimic liner. Cheers

      • Will the Mimic liner be available in a 22.5 for the women’s XTD and Hawk Ultra boots? I own one of each. Please don’t leave us out!

        • Don’t worry! We always make our women’s boots in true 22, and this definitely applies to the aftermarket liners as well.

    • Not marketing copy, nor was I stating my own preference. My day job is in a completely different industry., and all of my current boots are set up with about 16-17 degrees of effective lean (after spoilers etc). I used to use more when I was focussed on racing, but I can’t ski all day like that any more.

      I do try to acknowledge other viewpoints, and also where, say, older riders might be coming from.

      Also the bit about “no tip to drive” is overstated. I’ve ridden and effectively driven the shovels of FIS GS from a 12 degree boot. The difference is that your hips will be higher and your knees less flexed when in a balanced position, which changes (arguably “messes up”) transitions and absorption. I could not do a decent press in that setup, for example – Dropping my hips caused me to fall too far behind the ski.

  7. This was the longest discussion on liners and boot plastics I will ever listen to and cannot believe it was so interesting.

    It was boring and great at the same time , not sure if that can be explained

    Happy to hear I am not the only person with a perfect LV foot . Sucks for other pursuits , 97 last is my Cinderella

  8. That was a good listen. Who would have thought that boot building was so complicated.

    If possible I would really like to know more about boot flex, boot rebound and flex ROM. I note that Atomic test their boots using a robot and load cells which produces charts that show a boots flex paten and stiffness. No one ever mentions a boots rebound. I’m interested to know. What flex paten does a racer want vs freeride vs mogul skier and why? What rebound rates does a racer want vs freeride or mogul skier and why? Is there a place for a linear flexing boots? Does Atomic measure a boots rebound?

    The Atomic boot video shows a Hawx Ultra being flexed (measure in torque) through 0 to 15 degrees. The Hawx boot has an adjustable forward lean angle of 13-17 degrees and a foot ramp angle of 5 degrees. If you remove the foot ramp angle from the forward lean angle, the ankles dorsiflex is 8-12 degrees. When you add the 15 degrees of tested flex the ankle ROM will be between 8-12 and 23-27 degrees (or there about). What is the min and maximum ankle ROM that Atomic allow for and does this change with ski disciplined i.e. racers vs freeride vs mogul? How do Atomic stop over flexing?

    Atomic boot video:
    https://www.youtube.com/watch?v=HwMcaLDIb4o

  9. What does low/high volume foot mean? I have narrow feet but with very high arches/instep…? Do I need a narrow boot with a high roof or can the shell be stretched to provide more height?

    Along those lines it might be very helpful to do a session with Matt on fit suggestions for most common (and not so common) foot shapes.

    • Hi Mark, low/high volume can mean a couple of different things. Strictly speaking, it is overall volume of the foot, so a low volume foot will be on the smaller side and a higher volume foot will be on the bigger side for its size. But it can also relate to instep height, where low volume is a low instep and high volume is a high instep.

      It’s hard to say without being able to assess your foot in person, but usually I would get you a boot that matched your width (depending on how actually high your instep was) and then work on ways of increasing instep height within the shell (either stretching the shell upwards with a specific boot-fitting tool and/or reducing the height of the boot board. But again, the right solution really depends on your specific foot.

      Re: fit suggestions, this is honestly best left up to your boot-fitter because it really depends on the foot in question.

  10. Great Pod. Interesting stuff for sure.
    I’m likely going to pick up either the Hawk Ultra XTD or Prime XTD in the Fall.

    My alpine boots are Tecnica Mach 1 MV. Out of box fit was best I’ve yet experienced. They did require a couple small medial and lateral bunion bunches. Typically, a 98mm last would be too small, but given Atomic’s Memory Fit, I figured they’d be able to stretch out where needed while maintaining good heel and ankle hold (I have a small ankle and heel).

    Wondering at what width /volume of foot, one would be better moving to the Prime vs the Ultra.
    Looking forward to your thoughts.
    Thanks

    • Hey BK, if you can make an Ultra work with only 1st & 5th met punch, then go with an Ultra. And if you spend a lot of days in your boots, are looking to have a high performance fit and don’t mind visiting your boot-fitter once or twice, then I also recommend spot stretching vs. Memory Fit. This will ensure you get the performance you want but it might take a little longer to get there.

      • Thanks for weighing in here.
        I had a chance to stick my foot in the Ultra yesterday. I suspect that moulding the liners and spot punching for 1st and 5th mets would be sufficient.
        And yes, I do spend quite a few days in my boots and definitely looking for a high performance fit, especially around heel and ankle. But I’m surprised to hear you advise against Memory Fit. Would that not provide a greater amount of customization and thus better fit?
        Thanks.

        • Hi BK, Memory Fit is awesome for a lot of reasons but it should be seen as one of the ways to customize a boot, not the only one. For starters, it’s all about expansion- making the fit bigger, which is just one way to customize a boot. It’s great for when a boot-fitter needs to completely reshape a shell or cuff and numerous single stretches can’t do that or it would just take ages to do it (like trying to fit a Hawx Magna foot shape into a Hawx Prime boot, or a Prime foot into a Redster Club Sport). It’s great for skiers who don’t have the time to break in their boots and/or simply don’t have the time to make multiple visits to their boot-fitter. It’s generally not my first choice for skiers seeking a tighter fit or a more precise fit. Other techniques, such as spot stretching or grinding, would be better suited for absolutely ensuring a high-performance fit and/or for people who enjoy a tighter fitting boot. But ultimately, it just depends on the foot, what boot said foot is going into, and the skier’s own expectations/definitions of what constitutes fit, comfort and performance. It’s a great way to customize a boot, but it should be seen as one from a lot of possible options. Cheers, Matt

  11. Amazing podcast! thank you Blister, thank you Matt! I have just bought dalbello lupo ax 120 as it was perfect for my feet (I didn’t have much choice in the shop, though, tried slabs, scarpa xt, k2s).Later, I found out dalbello uses PP plastics! I am pissed off as I should have invested in better and already expensive boot. I will be getting XTD PRIME if they fit of course!

  12. This many comments after 4 episodes on boots. Who whoulda thunk.
    1. Are the Sole Canters going to play after your day of Telemarking? That would be a party.
    2. I have one of the first gen Lange XTs that I’ve just starting thinking about replacing. I went to a boot fitter recently just as a scouting mission and tried on boots. They ALL felt amazing…and then I got scared in left in a panic. It’s like I saw Charlize Theron in a bar and she starting winking at me. It’s cool, but it’s unnatural. I decided I wouldn’t go back to the fitters until I had copious amounts of time to find the boot that wouldn’t feel right for the first year I wore them. There’s that line, they don’t hurt but they don’t feel good, yet.
    3. If you do have a deep dive #5 on boots (again, the number of comments, there must be interest), ask whatever boot manufacturer happens to be on about liners and remolding. As a parent. I have a daughter who will stop growing in height this year, but teenagers continue to put on weight for some time after. Is remolding a viable path to take? That’s more of a likely scenario than working around ankle fracture pins.

  13. Went from heavily worked over Dobermann’s with Zipfit liners to Atomic Redster Club Sport 130’s with Zipfit liners. Amazingly it took One fit session only. Grilamid fit process was shocking to me how well it worked. Great stock boot angles for me. Fantastic boot.

    • Are those your everyday boots? Groomers, pow, crud, bumps?? I’ve been eyeballing those for next years boot. I’m 6’3″ 200lbs and ski 100 days a year. I destroy stock liners in about 50-60 days.
      Thanks

      • Chris, Yes they are my everyday boot. Beer league SL and GS to bumps. Actually I really like them in the bumps as they are very responsive. The most forward mount ski I occasionally use is a J-skis MasterBlaster. Currently skiing 60-75days a year with around 250days on the Zipfits. 5’11” 160-165lbs. Not quite as much suspension as the Dobermann’s but more responsive. Atomic knocked it out of the park with these. Really like the solid, bolt in forward lean angle adjustment. No B.S., just straight forward performance. Kudos to Atomic for posting all the specs on their website as well, no cloak and dagger shit here like most makers This model appears to remain off the radar for most but it shouldn’t be.

      • ZipFits are one of the few liners I’ve used that I consider to be near-indestructible even under a 200+ pound skier. Obviously I haven’t used mimic, so no opinion there.

        Injected foam can go pretty long as well depending on the mixture (hardener content etc), but as Matt pointed out those are hit or miss. If your foot is tweaked a little during the shot or if the fitter doesn’t get the flow balanced well between the medial and lateral channels then you either throw the liner away and start again, or ski like that for the next few years. I’ve had that happen and it’s really annoying.

        Other than that your traditional options are to treat liners as consumables and replace every so often, or the plug route and grind your foot shape into the plastic. In the latter case the liner can be very thin/firm and pretty durable.

        I haven’t tried moldable shells, mostly because the ones I’ve seen friends use to date seemed to be a one way ticket to unusably high volume. I imagine they have improved and will continue to do so.

        • FWIW I used to do plugs, but now I’m using a combination of ZIps in one pair of boots and “liner as consumable” in 2 others. All of the customization is in the shell anyway, and liners aren’t too expensive (except for Zips :-)

        • Geeking out one last time, I think the fundamental challenge is one of compressibility. Compressible materials fundamentally tend to take a set or “pack out” over time. The thicker and more compressible they are, the more they pack out.

          Zips last a long time because cork oil/resin is basically incompressible. It instead accommodates different foot shapes by flowing (very slowly and continuously). The Zip liners do have conventional foam forefeet, but they’re really thin and fairly firm. There isn’t much to pack out there.

          Injected foam liners likewise get around the problem by flowing (but only once, when injected) and then setting into a relatively firm and incompressible material, again depending on the foam mixture used.

          Moldable foams like Ultralon/EVA try to get around that by being very compressible when cooked for fitting, but relatively incompressible otherwise. They work well for a while IMO.

          What I understood Matt to be claiming is that parts of the outer layers of Mimic are compressible when cooked but near-incompressible (i.e. “solid”) otherwise. His comparison to 3M’s ScotchCast splint material is particularly telling IMO, at least to anybody who’s worked with that. I’m not aware of any technical reason why it wouldn’t be possible to make a material like that (as always $$$ are probably the biggest obstacle), but it seems that it could be a significant advance over what’s available today. It could potentially provide moldability with plug-like fit and durability.

  14. Finally I am no longer the lone voice of reason….. I have been preaching that forward lean in a boot is relative to how the thickness of the leg in the cuff sets the angle of the shin against the tongue…. and that ramp angle may require an adjustment dependent upon personal skeletal geometry, depending on combined binding ramp angle and boot ramp angle….. Finally great to listen to someone in skiing that does the math… binding ramp angles vary, so when added to the boot ramp angle, your actual total angle can vary…

    • Adjustable forward lean is honestly quite a nice system in Atomic boots. I usually try to fit from the ground up, focusing on heel lifts first, then adding a footbed, tweaking forward lean (when possible), and only then do I mess around with the boot environment.

      If I had my way, a proper bootfit would continue into seeing how the balance feels given binding delta, and lastly, playing around with different mount points via a demo binding. Such are the wages of obsession.

  15. Hi–great informative podcast. I’ve been using some Hawx Ultra XTDs and I think my feet will really appreciate the new Primes. Here’s my question: what is the biggest size you will make for the Prime XTD 130 or 120? If I’m not mistaken, 29/29.5 was/is the biggest size for the Ultras…any plans to go one size longer???
    Thanks again for the great information.

  16. Great info, but one thing that occurred to me is that the best technology is generally saved for the most expensive and stiffest boots. However, someone like me, who is an intermediate skier, uses a softer boot (e.g. 110 flex in my case) but would love to have the best fit also. Incidentally I bought new boots last year and they fit well (not Atomic although those had a decent fit but another brand fit me better – I have a really low instep). So the question is, is something like Mimic technology going to be available at lower price points/softer flex? Is it reasonable for example to substitute a Mimic liner into a softer flex boot? Would it affect the flex of the boot? Thanks for the great discussion.

  17. Is there a reason binding ramp angles weren’t considered in the total mix? Or did I miss it? The AFD on my P18s is about 14mm high, P14s about 16.5, heels being equal. The difference in feel and stance is dramatic, changing how a ski skis. P18s come with 1mm and 4mm shims, providing more opportunity to dial in the stance. But that takes some doing.

    Sure binding angles vary depending on BSL length (it’ like, science), but isn’t it worth being part of the conversation?

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