La Sportiva Tech Fittings — Overview

Post by blogger | January 15, 2019      

Readers asked me to detail the La Sportiva tech fittings. Here you go.

La Sportiva started their ski touring boot line around 2012 (has it been that long?). They’ve experimented with tech fittings since the fine day their first pair of ski touring shoes exited the injection mold. You could argue their S3 and S4 inserts, combined with the Trab TR2 binding, are the “Tech 2.0” that I ballyhoo more than is appropriate. Whatever the case, Sportiva tech fittings are not well documented. Perhaps the following will help.

Sportiva attempted to copy Dynafit fittings for their first effort,  circa 1012.

Sportiva attempted to use an aftermarket copy of Dynafit fittings for their first effort, circa 2012. These were the same fittings used by Garmont. During my testing the fittings had uneven performance. Some were fine, others did not release as smoothly as I like. Sportiva reportedly attempted to obtain fittings from Dynafit, but at the time Scarpa was the only licensee. These factors led to the Sportiva S3 fittings, covered below. For want of a better moniker, let’s call these originals the “S1” fitting, but they were really just an attempt to imitate the Dynafit OEM fittings. (The term OEM, as used here at, means “Original Equipment Manufacturer”).

Heel of the original, circa 2012.

Heel of the original S1 fitting, circa 2012. Close match to Dynafit. Worked fine.

S2? We don’t know what happened. But they jumped to S3…

On first glance, S3 toe appears similar to S1.

On first glance, S3 toe appears similar to S1. But it’s deeper, with a different shape. It’s designed to function optimally with the Trab TR2 binding, and also works with normal tech bindings. In testing, we found it might yield about half an RV value lower in lateral release, so test and adjust your bindings accordingly.

La Sportiva S3 toe fitting, showing visible difference.

La Sportiva S3 toe fitting, showing raised rib, visible difference.

S3 and S4 heels are the same.

S3 and S4 heels are the same. They match a classic tech binding heel fitting, with the addition of metal fittings for the Trab TR2 heel. The small shiny metal fittings at the top of the stack, with screws, are there for bindings such as Marker Kingpin or others that need a “DIN shelf,” remove them if you’re using a TRAB TR2 binding.

Sportiva S4 toe fitting is where they get radical.

Sportiva S4 toe fitting is where they get radical. Big thing is the obvious lead-in notch, but overall continuing the trend to difference.

What will S5 bring? Tech 2.4? Stay tuned.


Please Enjoy A Few Suggested WildSnow Posts


17 Responses to “La Sportiva Tech Fittings — Overview”

  1. Tyler Hislop January 17th, 2019 10:42 am

    Hi Lou, thanks for the fantastic blog.
    I wanted to comment on La Sportiva’s tech fittings. Last season, both my mom and I purchased pairs of the first generation Sideral boots (the women’s may have had a different name). Surprisingly, we both had issues with standard tech binding compatibility. My mom coordinated with half a dozen ski shops and was unable to get a reliable interface that would release in any predictable fashion. My own pair had quite a rough rotation at the toe and did not seem to be an ideal interface either. Both pairs were returned.
    Is this a problem you have heard of?
    At this time, I tour on a second generation Sideral and do not have any issues.

  2. Smokey January 17th, 2019 10:48 am

    RIP Wildsnow Blog

  3. Dabe January 17th, 2019 3:01 pm

    My $0.02 on the “din shelf” and removable shiny bits: I’m certain that they are only for the kingpin (which uses rollers at the heel to faciltate lateral release). I use my S3 equipped Sideral and Specte in TR2, TR Race, and Warden MNC and with the shiny bits gone, the shelf is more than adequate for the Warden (STH) heel to get purchase.

  4. Lou Dawson 2 January 18th, 2019 1:13 am

    Thanks Dabe, that’s a good clarification. Where I was coming from on that is that the “shiny bits” are necessary for the heel to have the DIN/ISO shape many bindings are designed for, whether they really need it or not, and yeah, Kingpin clearly needs the full shape.

  5. Pablo January 18th, 2019 6:27 am

    Lou what about step in action with S4 toe fittings?

  6. Brian January 19th, 2019 5:47 pm

    I had an early version of the Sideral (I think) in 2012. The boot ate one of my ankles for some odd reason so I sold them. But I skied them quite a bit beforehand, including the Otter Body on the Grand Teton. I was able to get a good sense of the overall design. Certainly, those early inserts were glaring in how different they were and not in a good way. They seemed shallow and that’s not something that was comforting dropping into critical terrain.

    Inserts aside, I felt that the crampon adaptability was funky, as well, due to the extreme rocker placed on the forefoot. But that’s another issue all together.

  7. Herb Jones January 21st, 2019 9:54 am

    Hi Lou,
    Have you or anyone else you know about tried to zero the delta(binding ramp angle) of the Fritschi Tecton?
    Do you know if it is possible without functional issues other than the obvious loss of ascender height?`
    I have a pair of the older black and yellow Spitfire’s which became the Sideral I believe, and I found some toe width issues as in the toe pins did not fit the same as they do with Dynafit toe inserts. This changes the angle of the binding arms and could account for release issues.

  8. Lou Dawson 2 January 21st, 2019 10:37 am

    Hello Herb, good point about the Sportiva inserts combined with Tecton/Evo toe. Should probably be verified as the Sportiva inserts are deeper and thus have a different width. As for ramp, my instinct says you could zero it, issue would be too much change in how the heel of the boot intersects the binding heel, and perhaps the sole of the boot might encounter the binding toe. Would be easy to bench test. How much rise do you think you need for what you feel is “zero?” Lou

  9. Herb Jones January 22nd, 2019 8:16 am

    Thanks Lou,
    The LaSportiva/tech toe issue was with a Dynafit toe. I forgot to mention that I swapped the Sportiva heel inserts with Dynafit’s because the heel pins did not fit snugly. Does not take much slop to create rattle there.
    I have not mounted the Tecton’s yet but, preliminary measurements are between 5 and 10 mm. lists the difference at 10mm but, of course, that varies according to ski thickness at the mounting point of the binding and must be measured from ski base to pin center/AFD surface for accuracy.
    Yes, interference of the boot sole at the toe area and maintaining proper heel hold down and lateral retention are my concerns. It is easier to zero tech fittings but, I usually have to cut relief notches in the sole rubber where the sole interferes as the toe is raised up. I have not attempted to angle the toe piece to maintain the stock alignment angles as shimming is problematical enough as it is, and finding long screws or making an intermediate riser plate adds to the work and sometimes, the weight. B&D makes a nice intermediate plate 6 mm thick which is a help but, not even close to the 15-16mm difference in toe to heel height of the Dynafits.
    It’s amazing that we often overlook the fact that these extreme ramp angles add to the forward lean angle of the boot as well as putting your feet in high heels.

  10. Lou Dawson 2 January 22nd, 2019 10:07 am

    Hi Herb, we had extensive ramp angle infos a long time ago… I hope you saw it all. I don’t think it’s necessary to measure binding heights from base of the ski, that is unless you’re racing the Hahnenkamm in a couple of days (smile), and factoring in the toe and heel fabric thickness of your socks. Here is a link.

  11. Cody January 22nd, 2019 2:14 pm

    Herb I use to have some Sportiva touring boots (v1 spectres) and had to adjust my Vipec pins a little bit, but after I adjusted them it worked fine.

  12. Herb Jones January 23rd, 2019 11:25 am

    Hi Lou, How did you know I was planning to do the Hahnenkamm on pin bindings??
    I must have a leaker in my ski mod laboratory. Yikes!!
    To the point, my interest in ramp angles is motivated by the fact that I went “barefoot” several years ago and needed to find a way to make my boot-binding-ski set up compatible as i found that skiing with footbeds and overly restrictive boots caused foot pain. I was fortunate to find the “Skier’s Manifesto” when my bootfitter, who had turned me on to “barefooting”, could not help, saying that his bootfitting philosophy had not changed. ?? The Skier’s Manifest is the “barefoot bootfit” method for anyone who’s interested. Long story, short: Ramp angle is part of the Manifesto bootfit equation and one of the most overlooked and belittled parts of bootfitting in general. So, bootfitting is complicated enough without adding binding ramp or “delta” into the equation.
    David MacPhail, the author of The Skier’s Manifesto, is currently doing his own ramp angle research and is finding that no one has been functional above 2.8 degrees, with many people less than 2.0 degrees and that some skiers are sensitive to as little as 0.1 degree! I have found that a 1mm shim in my boot under the ball changes ramp angle by almost 0.3 degrees when measured between the heel and the ball of the foot. So, no, a mm at the toe or heel piece is not as much angle (over a longer length) but, reducing variables helps in the whole process of boot-binding-ski setup. Socks? Not so much but, absolutely part of the fit equation.
    Have you tried the Lenz Heat Socks yet, Lou ? I am finding them much more effective than the Hotronics. Herb

  13. Lou Dawson 2 January 23rd, 2019 12:16 pm

    Herb, I got a smile out of that! Thanks. And sure, I totally agree that very small changes in ski and boot geometry can be felt, and have an effect. If it’s necessary to include ski thickness in ramp measurements, not hard to do. Most skiers probably don’t need to go that far, but I feel anyone can benefit from paying some attention to the issue, especially when it comes to swapping gear.

    And yeah, be sure your socks don’t throw off your metrics!


  14. herb Jones January 23rd, 2019 1:50 pm

    Hi Lou, Thanks for the link to the extensive and informative binding pin height data.
    The angle data is helpful and importantly shows how BSL/shell size can affect angle. I did run into the pin insert height variable last year with the TLT5 and LaSportiva Spitfire as I always check Net Ramp Angle on the ski with the ski base leveled. This year I found that the Atomic Hawx XTD inserts were the same height . So much easier to check boot ramp without having to put it into the binding every time.
    I noticed that the chart explanation above the chart suggests that a boot with the same pin insert height is a boot with zero ramp. I am sure this is not what you intended but, as a “ramp nerd” felt compelled to mention it. Respect to you for good editing in your posts and comments.!
    I’m thinking I will go with a zero base edge bevel for the Hahnenkamm since it’s usually boilerplate. What would your experience suggest? Also, where can I get a pair of DIN 8-18 pin binders?


  15. Lou Dawson 2 January 24th, 2019 9:05 am

    Hi Herb, thanks for pointing out that “0 Ramp” misstatement. I’ll check and edit.

    Some pin bindings have such a high vertical release-retention setting option you probably could run a race on them, though probably not the Streif, as the binding would probably just fly apart. The stiffest springs for the Atomic-Salomon MTN are probably about DIN 16 for vertical release, and you can lock out the toe for probably about the same. Lou

  16. PEZ January 25th, 2019 6:09 am

    Hi Thank you for great article! Still haven’t got shift fitted and bought most comfy boots for me -LS Spectre2.0. Does La Sportiva S3 toe fitting is a problem for shifts in DH mode? Will i have to smooth toe fittings down with a file?Thnak you for you help and great article

  17. Lou Dawson 2 January 25th, 2019 9:10 am

    I think you’ll probably need to file down the fittings, easy to check, just put the boots in the Shift binding and see how the rollers ride on the fitting. Lou

Anti-Spam Quiz:

While you can subscribe to comment notification by checking the box above, you must leave a brief comment to do so, which records your email and requires you to use our anti-spam challange. If you don't like leaving substantive comments that's fine, just leave a simple comment that says something like "thanks, subscribed" with a made-up name. Check the comment subscription checkbox BEFORE you submit. NOTE: BY SUBSCRIBING TO COMMENTS YOU GIVE US PERMISSION TO STORE YOUR EMAIL ADDRESS INDEFINITLY. YOU MAY REQUEST REMOVAL AND WE WILL REMOVE YOUR EMAIL ADDRESS WITHIN 72 HOURS. To request removal of personal information, please contact us using the comment link in our site menu.
If you need an emoticon for a comment just copy/paste off the following list, or use text code you might be familiar with.

:D    :-)    :(    :lol:    :x    :P    :oops:    :cry:    :evil:    :twisted:    :roll:    :wink:    :!:    :?:    :idea:    :arrow:   
Due to comment spam we moderate most comments. Please do not submit your comment twice -- it will appear shortly after approval. Comments with one or more links in the text may be held in moderation, for spam prevention. If you'd like to publish a photo in a comment, contact us. Guidelines: Be civil, no personal attacks, avoid vulgarity and profanity.

  Your Comments

  Recent Posts

Facebook Twitter Email Instagram Youtube


  • Blogroll & Links

  • Welcome to Louis (Lou) Dawson's backcountry skiing information & opinion website. Lou's passion for the past 50 years has been alpinism, climbing, mountaineering and skiing -- along with all manner of outdoor recreation. He has authored numerous books and articles about ski touring and is well known as the first person to ski down all 54 of Colorado's 14,000-foot peaks, otherwise known as the Fourteeners! Books and free ski touring news and information here.

    All material on this website is copyrighted, the name WildSnow is trademarked, permission required for reproduction (electronic or otherwise) and display on other websites. PLEASE SEE OUR COPYRIGHT and TRADEMARK INFORMATION.

    We include "affiliate sales" links with most of our blog posts. This means we receive a percentage of a sale if you click over from our site (at no cost to you). None of our affiliate commission links are direct relationships with specific gear companies or shopping carts, instead we remain removed by using a third party who manages all our affiliate sales and relationships. We also sell display "banner" advertising, in this case our relationships are closer to the companies who advertise, but our display advertising income is carefully separated financially and editorially from our blog content, over which we always maintain 100% editorial control -- we make this clear during every advertising deal we work out. Please also notice we do the occasional "sponsored" post, these are under similar financial arrangements as our banner advertising, only the banner or other type of reference to a company are included in the blog post, simply to show they provided financial support to and provide them with advertising in return. Unlike most other "sponsored content" you find on the internet, our sponsored posts are entirely under our editorial control and created by WildSnow specific writers.See our full disclosures here.

    Backcountry skiing is dangerous. You may be killed or severely injured if you do any form of ski mountaineering, skimo randonnee and randonnée skiing. The information and news on this website is intended only as general information. Due to human error and passing time, the information, text and images contained within this website may be inaccurate, false, or out-of-date. By using, reading or viewing the information provided on this website, you agree to absolve the owners of Wild Snow as well as content contributors of any liability for injuries or losses incurred while using such information. Furthermore, you agree to use any of this website's information, maps, photos, or binding mounting instructions templates at your own risk, and waive Wild Snow owners and contributors of liability for use of said items for ski touring or any other use.

    Switch To Mobile Version