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 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 WildSnow.com, means “Original Equipment Manufacturer”).
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. 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 raised rib, visible difference.
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. Big thing is the obvious lead-in notch, but overall continuing the trend to difference.
What will S5 bring? Tech 2.4? Stay tuned.
17 comments
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.
RIP Wildsnow Blog
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.
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.
Lou what about step in action with S4 toe fittings?
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.
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.
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
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. Skimo.com 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.
Herb
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.
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.
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
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!
Lou
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?
Herb
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
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
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
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