WildSnow Technical — Dynafit and Tech Binding Heel Gap Spacing and Safety Release

Post by WildSnow.com blogger | August 23, 2016      

You’ve heard of the generation gap, and you might know about your spark plug gap, but what about the Dynafit tech gap? And now, the “kiss gap?”

To function properly, most “tech” type backcountry skiing bindings require specific spacing between the boot heel and the rear unit of the binding. The “tech gap,” if you will. In this WildSnow.com technical blog post, we’ll look at the “tech gap,” with emphasis on Dynafit brand bindings though the concepts apply to other brands as well.

Illustration of small gap used for spring-loaded tech binding.

Dynafit Radical 2.0 heel unit, with ‘kiss gap’ adjusted to what we think works best, a very small gap that just allows a sliver of light to come through. We recommend this method because it insures you are not pushing the heel unit up too tightly against the boot heel. Note that some Radical 1.x bindings have a spring-loaded heel unit that moves fore/aft, but still requires a 5.5 mm gap! Confusing? You bet. (Note the binding shown here is all black and may be confused with Radical version 1, current versions of Radical 2 have green and gold components that make it easily identifiable.

Before we get started, fair warning: Due to numerous Dynafit binding models that look similar, have the same names and sometimes were even sold under the same SKU number, the issue of proper adjustment has become incredibly confusing. We feel that competent ski shops who deal with this issues daily are in many cases better than efforts at DIY. Even so, beware of the ski shop as well. They’re only human and can be easily confused as well.

2016 autumn addendum: We added a few photos at bottom of post to clarify how the tech binding pins should appear with a “classic” tech binding such as Dynafit Superlight 2.0.

2016 addendum: Certain tech bindings are now sold that specify a tiny gap at the heel, as illustrated in photo below. We call this the “kiss gap” and define it as setting the binding heel as close to the boot as possible while still being able to see a small sliver of light coming through a tiny gap. We use the term “kiss” because the best way to perform this adjustment is to move the heel unit to the point where it lightly touches the boot heel, then back off a tiny amount. While doing this adjustment, be sure to tap and wriggle the heel unit to make sure it’s not catching on its spring loaded track and giving a false impression of where you have it adjusted. Mainly, bindings using “kiss gap” MUST HAVE HEEL UNIT ON SPRING LOADED TRACK THAT MOVES FORWARD AND BACK. Examples of such bindings are the Dynafit Radical 2.0, Dynafit Beast, G3 ION. Unless you are sure about binding having spring loading or not, check binding literature for specified heel gap, and evaluate spring loading by manually moving the binding forward and back by inserting boot and observing behavior. Using a “kiss gap” with a rigid binding heel that’s not spring loaded will result in binding destruction that can cause injury or death.

With regards to Radical 1.x, while it was made with both a spring loaded heel unit and in an earlier version without BOTH USE THE WIDER HEEL GAP DETAILED BELOW. Note, we suspect that at least some part of the Dynafit Radical 1.x heel breakage we’ve seen in 2014-2016 is the result of improperly setting the heel gap.

See this blog post about “in line” change made to Dynafit Radical binding model 1.x that introduced the heel unit fore-aft travel spring system.

2013 addendum: a new feeler gauge is being sold with Dynafit bindings. See photos below.

Dynafit Radical 1.x models: Use the little white gauge as pictured below to set the 5.30 mm heel gap (official specification “5.5 mm” but the gauges measure more like 5.30 with our calipers). Only difference in original procedure is you need to double-check your heel gap by taking boot out of binding heel, snapping back down again, then pushing heel unit firmly towards boot heel before checking the gap again. Idea is to take up any lingering slack in the 2013/2014 heel elasticity system so you don’t end up with too wide a heel gap. We’re not sure why the gauge was changed from a solid plastic “shim” to the compressible device, but it works so whatever. (Two nickels and an American quarter coin measure about 5.30 mm. Three nickels measure about 5.5 mm. Be aware that the Dynafit gauge is not to be compressed completely closed, you just line up the “teeth” as illustrated to get the <> 5 mm gap.)

Note that _NO_ RADICAL 1.X USES THE “KISS GAP” SHOWN ABOVE, BUT ALL RADICAL 2.X DO USE THE SMALLER “KISS GAP.” Dynafit Radical bindings can appear quite similar upon cursory glance. To identify 2.0 version Radical, verify existence of rotating toe unit along with the substantially reinforced and re-designed heel unit visible in photos. Color schemes of bindings vary, so don’t go by colors. For example, the Radical 2.0 used to illustrate “kiss gap” above is an all black version, but other color schemes exist as well.

The gauge for heel gap is now a compressible little device as pictured.

The gauge for heel gap is a compressible little device as pictured. It's a bit confusing to use. Don't over-think it, just line up the parts as indicated in photo and you've set your heel gap to plus-minus 5.3 mm.

We're assuming the idea of this gauge is you start with your gap a bit wide, then carefully crank the gap closed.

We're assuming the idea of this gauge is you start with your gap a bit wide (see more about this below), then carefully crank the gap closed till the gauge closes to the point as shown in photo above this one. Beware, the idea is NOT to completely close the gauge, but rather to line up the ends of the tiny nibs, again, as shown above. Thanks Seth for the photo.

2011 clarification: All Radical series and Vertical series Dynafit bindings use a 5.5 mm gap at heel, per discussion above and below. Our calipers measure this as more like 5.30 mm, but that falls within our understanding that a .5 mm variation in heel gap is acceptable as a tolerance.

Dynafit feeler gauge

Dynafit 5.5 mm feeler gauge inserted between boot heel and ST model binding.

Photo above shows the correct way of setting your tech gap specific to Dynafit bindings, using the feeler gauge that’s shipped in the box with all Dynafit bindings. Boot should be snapped into the binding heel (downhill mode). Gauge should be inserted snug, but not forced. Adjust gap via the rear adjustment screw on the rear of the binding baseplate. No need to get your panties in a bunch over how this is done. So long as the gauge fits in there snug, the binding gap is set. A tiny bit of variation, say 1/2 mm, is fine. How do I know that? Because as you ski and your ski flexes, the gap varies immensely! Thus, a tiny bit of variation when you set it is obviously within tolerances. That said, I’m talking a tiny variation — not just eyeballing and calling it good.

Simple, eh? But just as the generation gap caused confusion, so does Dynafit’s gap result in cognitive dissonance. Prior to around 2010 Dynafit’s literature states the gap should be 6 mm for the Comfort/ST/FT models, and 4 mm for the TLT/Speed/Race. Only when measured with calipers, the newer white plastic ST/FT gauge measures 5.43 mm, and the older one measures 5.9 mm. Latter is close enough to 6 mm as to make sense, but regarding 5.43 mm, do we suddenly have a new specification they snuck in on us? The answer is yes. (Note, pins in TLT/Speed/Race will remain the same length, and require a 4 mm tech gap.)

Dynafit gap gauges

Dynafit gap gauges, 4 mm TLT gauge to left, earlier Comfort/ST/FT 6 mm gauge in middle, new 5.5 mm gauge to right.

I’m actually not surprised about the the 5.5 mm spec, as I’ve been using approximately that spec for years on flexible skis which when decambered radically end up popping the heel pins out of the boot heel.

But nothing is perfect. By the same token, with flexy skis you may find that when set at 5.5 mm and using heel-flat-on-ski mode , the smaller heel gap results in your boot heel catching on the binding when your ski bridges a gap such as a creek crossing, or while you’re breaking trail in deep low-density powder. This problem is actually quite common for larger skiers with heavy packs.

Dynafit heel gap

Dynafit heel gap in heel-flat-on-ski touring mode. In certain situations the gap indicated by arrow can close up and result in our boot heel catching on the binding. Setting the gap at 5.5 mm may exacerbate this problem. If so, set at 6 mm but beware release values that are changed when the gap is changed.

So besides touring clearance, what exactly does changing the boot gap do to Dynafit binding performance?

1. The gap between boot heel and binding is there so the ski can flex without jamming your boot heel against the binding heel unit. BUT, it’s also there so the boot can rotate out of the binding without catching during a safety release. Even so, it is my opinion that if you require lateral release when the ski is flexed and the gap is closed up due to ski flex, the heel of the boot can still catch on the binding and cause a spike in side release value. (Update: this is part of the reason binding makers have added spring loaded heel units that move forward and back on a track.)

Above can be easily simulated on the bench by adjusting the tech binding heel gap to nearly nothing, then hand checking the side release by rotating the heel unit. If you’re not convinced after that, take a fairly flexible ski with correctly set gap, stick a boot in the binding, suspend between two chairs and press down on the boot to flex the ski. You’ll notice it’s fairly easy to close up the tech gap. With the gap closed and ski loaded, try rotating the heel unit to simulate a lateral release. Observe that the heel unit may bind while rotating. To mitigate this effect, correctly milled boot heel fittings in tech compatible boots have an elongated horizontal slot that adds clearance (and also aids in ice ejection). Even so, in a worst case scenario (supple ski flexed to the max), you may still get this effect as demonstrated in the “two chair suspension test.”

(Boot buyer caveat: As I covered in a previous post, there is no standardized norm for tech boot fittings and milling, so some boots are still being made without this elongated slot. Buyer beware. Latest news is that an inter-industry boot configuration standard is in process for tech fittings, but such could take years if it ever happens, so don’t hold your breath. Instead, read WildSnow.com.)

2. As the heel tech gap varies, release values vary because the boot is exerting differing amounts of leverage on the pins. When the gap is smaller, the release values are higher (at least that’s what logic dictates, I did not test this). Thus, in my view, it’s possible you could get a spike in lateral release value if you happen to need a release when your ski is radically flexed. To mitigate, as always I advise setting your release values at the low end of what’s recommended in the DIN/ISO 11088 chart, and only increase if you have problems with pre-release. Also, I recommend setting vertical and lateral release independently. In other words, they don’t have to be the same number. This being said, it’s also true the if you de-camber (reverse flex) your ski and widen the tech gap, you’ll end up with lower release values while the ski is flexed. Such a situation might arise, for example, when doing something like making a hop turn with heavy snow piled on the tip and tail of your ski.

Dynafit backcountry skiing binding heel rotation.

Dynafit backcountry skiing binding heel rotation during release. Note how the elongated horizontal slot in the boot heel allows the boot to eject without catching on the pins.

In my understanding, variation of the heel gap while in real world use is the main reason why Dynafit and other tech type bindings are not TUV certified to the DIN/ISO 13992 standard for tour binding release. In other words, while the Dynafit has a proven safety release, and I know for a fact the company does work hard to keep the release value numbers matching those of the DIN/ISO standard, as the ski flexes those values vary.

Conclusion one: In my view, while most (if not all) frame touring bindings such as Fritschi are TUV tested/certified to meet DIN/ISO standard 13992, boot wear and dirt (as well as user adjustment error), result in wide variations of release values during real-world use. The beauty of the tech (Dynafit) binding system in terms of safety is it eliminates the variable of boot friction by suspending the boot between toe and heel fittings. Conversely, the tech system introduces the problem of ski flex and heel/binding clearance and they are thus not TUV certified to DIN/ISO 13992. Even so, real life use validates my opinion that both tech and frame binding systems are equally as safe — when correctly maintained and set with proper clearances. Main caveat being that any binding system should be carefully adjusted and tested for safety release.

Conclusion two: The 5.5 millimeter Dynafit tech gap will probably work fine for the vast majority and is recommended. But if you have problems, don’t hesitate to experiment with small changes in the gap. Only if you do so, be aware that by changing the gap you’ll change your release values or possibly introduce annoyances such as the pins actually pulling out of your boot heel fitting when the ski is de-cambered (in this case, exacerbated by gap set wider than spec).

Conjecture: It seems to me that actually making the tech binding pins longer and specifying a wider gap would be the way to go for all tech binding makers. But everything is interrelated in this type of machinery, so who knows what problems that would introduce. Even so, a man is allowed to dream. It also occurs to me that perhaps ultimately we need a generation II tech binding interface. One with stronger and wider boot heel fittings, variable spring tension in the toe unit, longer heel pins, and so on. Is someone working on that as I dream? I wouldn’t be surprised.

Tip: If you can’t find a Dynafit tech gap gauge, 3 lightly used nickles measures about 5.5 mm, which in my opinion is within tolerance for setting your Dynafit tech gap.

TLT6 Dynafit boot set up with Superlite  2.0 binding.

TLT6 Dynafit boot with Superlite 2.0 binding inserted with IMPROPER TECH GAP to illustrate how binding would appear when ski is heavily flexed and the tech gap closes up. Notice how the binding socket-cavity has enough depth to accept the total length of the pins, with a little extra.

TLT 6 boot set up with Superlite 2.0 binding per Dynafit recommended tech gap using supplied gauge.

TLT 6 boot set up with Superlite 2.0 binding per Dynafit recommended tech gap using supplied gauge. Note how the depth of the boot socket allows room for the pins to move inward during ski flex, yet with ostensibly enough pin length riding inside the socket for situations when the ski is de-cambered (reverse flexed) and the pins slide outward to the rear and can thus possibly come completely out of the socket, causing accidental release.


Please Enjoy A Few Suggested WildSnow Posts


173 Responses to “WildSnow Technical — Dynafit and Tech Binding Heel Gap Spacing and Safety Release”

  1. KJ February 17th, 2010 1:26 pm

    Nice tip. I believe, though, that 3 nickels is 5.85mm – 1.95mm x 3, see http://en.wikipedia.org/wiki/Nickel_(United_States_coin) . Love the site!

  2. Lou February 17th, 2010 2:02 pm

    Slightly worn real-life nickles, not mint (grin).

  3. Clyde February 17th, 2010 2:56 pm

    I found with the Onyx, if the gap is a hair too small, you can’t install the brakes. So far, very happy with the G3.

  4. Lou February 17th, 2010 3:02 pm

    Had not evaluated that yet Clyde, so much thanks for pitching in.

  5. cam February 17th, 2010 3:19 pm


    could you explain your situation with the ONYX further? the gap setting shouldn’t be related in anyway to brake installation unless I’ve missed something. The only thing that could hinder brake installation related to length adjustment would be if you’re too close to the end of the adjustment range (ie. heel all the way backwards) you can tell where you’re at by looking at the side of the heel to see if you’re in the proper range.

    glad to hear you’re happy with the binding.

  6. Oli C February 17th, 2010 3:42 pm

    getting the distance set-up is very important. i’m fairly young and only on my 2nd season of touring, this season i got a new lightweight set-up with dynafits tlt’s to complement my bigger ski’s with fritschi’s. aux veux campier in strasbourg fitted them to my ski’s. i thought they’d do a good job, i’ve not had any issues with the camper in albertville at the heart of the Savoie region of France. But alas i kept comin gout at the toe’s, even in climbing mode. a local shop here in austria said the gap was too big between the heel of the boot and the dynafit heel peice. Since they re-drilled them i have had no problems at all, up or down!

  7. Zephyr February 17th, 2010 4:43 pm

    The reviews are excellent. May I suggest using actual measurements on boots such as Cm measurements of last size, interior of boot at heel, toe, height for accuracy. It makes it easier to quantify fit and less subjective. Same thing for skis flex, say with 50 lb weight and cm deflection at midpoint, 12″ from tip and tail. We do this for weight by gram rather than say, heavy, light etc. I believe it will be helpful to all readers. Thanks.

  8. Zephyr February 17th, 2010 7:36 pm

    You’ve done it already. I missed it. Thanks. Good standard for procedure.
    ZZeus=105 Factor=102.

    ankle area room, distance between the shell cuff rivets is a good indicator.
    ZZeus=86, Factor=88.

    heel pocket at a standardized spot.
    ZZeus=76, Factor=71.

  9. John W February 17th, 2010 7:59 pm

    My bench test is to put the boot in the binding w/ heel at no rise. Put the tip and tail on a piece of 2 x 4 and push the ski to the bench. Hold it down and lift the heel up (simulate walking). If there is contact move the heel back a bit and retest. I think it’s hard on the binder to be making repeated contact.

    A 1/4″ drill bit is 6.35 mm. Good for a 6 mm ball park fit if you lost the gauge.

  10. Wyatt February 17th, 2010 9:08 pm

    I bought some used skis with Dynafit Verticals mounted but did not get the spacer and I was racking my brain to find something quick and easy to set the gap with. I ended up using a metric allen key. The 6mm allen key is exactly 6mm across the flats and worked well.

  11. Lou February 17th, 2010 9:57 pm

    Wyatt, good tip on the allen wrench. Now that the standard is 5.5 mm, what do you think will work best for that?

  12. Gus February 17th, 2010 10:59 pm

    I was in a ski shop just a few days ago and someone came in with a Garmont boot and Dynafit TLT ST binding. The pins had pushed directly up past the tech insert in the heel and dug a deep gouge into the boot plastic and then out. So the heel of the boot had two vertical gouges in the plastic caused by the pins. My guess is that he took a wicked jump and flexed those skis way beyond normal so the boot bottomed out on the ski surface and the heel pins dug their vertical craters. Has anyone seen this before?

  13. Wyatt February 18th, 2010 12:54 am

    A 5.5mm or 7/32″ hex key should do the trick. Of course neither is as good as the supplied plastic piece because of how you have to fit it in while you are adjusting the screw, but its close enough for me.

    So how do I tell whether my bindings should be 5.5 or 6?

  14. Matus February 18th, 2010 3:44 am

    Just a note regarding the setting of the gap:

    The skis need to be flat when adujsting the gap. I.e. first, push the ski down to the flat floor, hold it that way, then put the spacer between the boot and the binding and adjust the distance with the adjustmen screw.

    As far as I remember, the above is also in the user manual…

  15. Jan February 18th, 2010 5:20 am

    @ Lou: remember – G3 is a cheap copy of Dynafit, don’t be surprised, if the gaps and the tolerances are different from the original!

  16. Schnappi February 18th, 2010 6:48 am

    Gus wrote: “I was in a ski shop just a few days ago and someone came in with a Garmont boot and Dynafit TLT ST binding. The pins had pushed directly up past the tech insert in the heel and dug a deep gouge into the boot plastic and then out. So the heel of the boot had two vertical gouges in the plastic caused by the pins. My guess is that he took a wicked jump and flexed those skis way beyond normal so the boot bottomed out on the ski surface and the heel pins dug their vertical craters. Has anyone seen this before?”

    I’ve had it happen 3 or 4 times, after hucks, but without damage to my ZZeros. The heel shelf just ends up underneath the pins. As far as I recall, it has happened only on rigs where I was not using brakes.

  17. Lou February 18th, 2010 9:11 am

    I’ve had this happen as well, when the pins ended up on top of the heel shelf. Not sure how it happens, but it happens with TLT binding with shorter pins. New version of TLT will have the longer pins, which is something I’ve pushed for since years ago.

  18. Lou February 18th, 2010 9:17 am

    Jan, I wouldn’t call G3 “cheap.” They are very nicely made. As for the “tech gap” for the G3, it’s 6 mm, same as Dynafit Comfort/ST series up till recent bindings being shipped with 5.5 mm spacer/gauge.

  19. Dave February 18th, 2010 10:50 am

    Lou-I just had my Dynafits mounted by a shop (I”m new to AT), and are noticing some of the rubbing of boot to binding you describe when in flat-on-ski-mode. Its just on one side, but not just when applying abnormal pressure (like a creek crossing) Should I just back the adjustment off slightly to address this? Also, slightly off topic, when I was looking this over, I noted that the shop did not put in the 5th screw in either of the toe pieces-the lone one at the top, under the lever. Is there a reason for this? I’m not worried about the extra weight, and I’m kind of a big guy, so I’m tempted to take it back and have them installed. Thanks, as always.

  20. Jonathan Shefftz February 18th, 2010 7:22 pm

    “In my understanding, variation of the heel gap while in real world use is the main reason why Dynafit and other tech type bindings are not TUV certified to the DIN/ISO 13992 standard for tour binding release.”

    I found some interesting language in the user manual on that. In the 2006 version: “As an authorized retailer you agree to check all the equipment according to DIN/ISO 11088 before the installation or adjustment of the function unit ski / ski binding / ski boot. If necessary, you have to replace one part of the unit or all three parts. All parts have to be in accordance with DIN / ISO standards.”
    And then: “All new DYNAFIT bindings are in accordance with the requirement of the existing national and international standards and are inspected by the TUV Product Service.”
    But that sentence changes in the 2007 version to: “All DYNAFIT bindings are 100% checked for their release values during production, in compliance with statutory regulations.”

  21. Lou February 19th, 2010 7:20 am

    Jonathan, as far as I know there is no presently manufactured “tech” binding that is certified by TUV to the DIN/ISO release norm. Early TLT bindings did have some kind of TUV certification, and word is that the bump molded on the binding surface behind the boot heel was there for the sole reason to prevent the gap from changing past the point where the DIN/ISO norm would exceed tollerances. Even that was dicy and introduced it’s own problems, so both the bump and TUV certification went away. That’s my understanding, anyway, from a variety of sources.

    From everything I’ve heard TUV can be very difficult to deal with, nor is there an industry standardized norm for the tech boot nor the binding. Instead, a voluntary standard for tech binding release values is what’s ensued, which is intended to match DIN/ISO. My understanding is that companies such as Dynafit and G3 make every effort to make their release values conform to the DIN/ISO norm for release values even though TUV will not certify tech bindings for it. Many other companies making tech bindings appear to not even bother with that.

    Also regarding TUV, anyone can bring them their own in-house standard/norm and pay them to do independent testing for that standard. So just because a product is “TUV” doesn’t necessarily mean it conforms to any particular standard other than what it was tested for. Along with any TUV logo or certification, one needs to know what standard that applies to before making any assumptions.

    Lot’s of potential for smoke and mirrors with this stuff. Main thing is that based on observation and field experience, tech bindings such as Dynafit or Onyx prove out to have just as good (or better) safety release as other touring bindings. But as with all touring bindings, safety release should be set conservatively low and only dialed up if necessary. If for no other reason than as stated above, tech binding release values do vary when the ski flexes.

  22. Glomstulen February 19th, 2010 8:59 am

    A bit off topic, but anyone knows when the skitrab tr1 binding will come out? Lou, have you tested it yet?

  23. Jonathan Shefftz February 19th, 2010 9:07 am

    Interesting with TUV — the Dynafit user manual has all the same release value adjustment and testing protocols as alpine downhill bindings, and keeps referring to various ISO standard numbers, but never comes and says either way regarding whether it really meets them.
    Glomstulen, the TR1 prototype is now the TR2. If you look at the WildSnow Twitter feed (going to the standalone page, which shows all the older tweets), I put a link to a video that shows a pretty good demo. The big change is that the binding requires a new proprietary heel interface. The demo shows a Scarpa boot — unclear if Trab is planning some sort of arrangement with Scarpa, of it that was just a Trab mod of a Scarpa boot.
    Maybe the idea with the custom heel unit interface is that Trab can sell after-market custom heel pads for Dynafit Zzeus/Titan/Gaia, BD Factor/Method/Shiva, and Solly Quest series?

  24. Dave February 19th, 2010 10:09 am

    Lou: I just got my first dynafit setup and am having the rubbing you describe in heel-on-ski tour mode, although it is not just happening at creek crossings, but in general touring. Is that solvable by simply adjusting the heel? Also, the bindings were mounted at a shop and they left out the 5th screw in the toe piece, under the toe lever. Is this common, or should I take them back and get the screw added? Thanks.

  25. Lou February 19th, 2010 10:29 am

    We’ll, you just want to check the tech gap. If it’s the correct width for your binding model it shouldn’t be rubbing other than in extreme flex situations. What binding model? Don’t just willy nilly back it off, use the spacer gauge that came with the binding. If the shop didn’t give you the gauge, then they owe you.

    As for 5th screw, all next season’s offerings will eliminate that, but I’m pretty sure current models still need it.

  26. Dave February 19th, 2010 11:00 am

    Thanks, Lou. Its actually the exact same setup on this page-Waybacks with Vert STs. I didn’t get the spacer so I’ll be making a trip back to the shop for that and the 5th screw. Maybe I should stick to tele 😉

  27. John February 19th, 2010 11:49 am

    I’d feel better if they kept the 5th toe srew, particularly for lightweight BC skis. I have 5 or 6 different sets of skis with FT-12s or STs and have never had a release issue, even have a torn MCL. I run a DIN of 8 for forward release and 10 for rotational release. Last week I Tomahawked in Maroon Bowl on my RT-86s w/ first gen FT-12s, which caused the toe piece to rotate enough that the heel pins did not line up after the fall. Re-tightening the screws fixed the problem. (I usually epoxy when I mount, these were shop mounted with a non-epoxy adhesive).

    Just saying there is a lot of force on the toe piece, and BC skis with little top sheet reinforcement, may need this extra mounting point for rotational strength.

  28. Lou February 19th, 2010 12:04 pm

    Hence, I always use epoxy or Gorilla Glue, wood glue is for building kitchen cabinets…

  29. rod georgiu February 20th, 2010 11:25 am

    :wub: Lou, you talk about flexy skis where you might come out of the binding. Not sure how flexy the skis have to be. I use K2 Hardsides with FZ-12. Would you consider them to be flexy?

  30. Lou February 20th, 2010 11:43 am

    It would depend on your weight, the weight of your pack, and in what type of conditions you’re using the skis. I wouldn’t call the Hardside “flexy” per se, but performance depends on a lot of factors. Are you having trouble staying in the binding, or did this blog post just give you another thing to worry about along with world hunger? :angel:

  31. rod georgiu February 20th, 2010 11:56 am

    Are you having trouble staying in the binding, or did this blog post just give you another thing to worry about along with world hunger?

    You got that right. I skied the FZ-12 s 6 times this year, and never came out. I am new to Dynafits. True that when I skied a steep (for me- 45 degrees ) culoir, I locked the front.

  32. Lou February 20th, 2010 12:32 pm

    Don’t worry, be happy, la, la la la la la, la la laaa la laaa, laala la la…. and all that.

  33. Dorey February 20th, 2010 6:41 pm

    This is also a shade of topic. I just got my first Dynafit boots and bindings,and skis in a package delivered, pre-mounted. No shim included so I made one. Set, tested DIN, and all is good. (Thanks for all the available tips. )I had the brakes shipped separate so I can get used to mode changes without them.

    In your extremely helpful Dynafit FAQ’s you mention that the boot rise is several mm’s high. I’m not sure whether the boot is lalso supported somehow below that rise. My boots, (without brakes) are suspended, consistent with your measurements way up there and supported only by the 4 pins. Is that a correct situation>>

  34. Lou February 20th, 2010 9:56 pm

    Yes, with Dynafit bindings the boot is suspended between toe and heel.

  35. Lou February 22nd, 2010 12:48 pm

    In original version of post above, I mentioned that Dynafit would be going to longer pins in the TLT/Speed model, so it would match the Comfort/ST/FT series with a 5.5 mm tech gap instead of the usual 4 mm. I got that info from a reliable source and wrote it in. But it turns out I got it wrong. The pins in the TLT/Speed will remain the same and that model will require a 4 mm gap.

  36. harpo February 23rd, 2010 11:25 am

    Are thy removing the 5th scew to save weight? Seems problematic as I have heard of problems with dyna toes pulling out of some skis, with blame put both on the core material of the ski and the close set pattern of the screws in the toe peice. I would feel better if they kept the 5th scerw……..

  37. Lou February 23rd, 2010 11:32 am

    Harpo, 5th screw really does nothing more than hold down the binding under the latch, it would have very little effect on overall binding pullout strength. I would be very surprised if a Dynafit toe pulled out after being mounted correctly in the area of the ski that’s reinforced for binding placement, even with 4 screws.

    As for why they left it out, probably for simplicity and cost savings more than anything, but it also saves weight, and since the weight of the binding has been creeping up like some sort of creature in a zombie film, reversing that trend is a good thing.

  38. roca February 25th, 2010 4:00 am

    Very intersting new product from last ISPO:
    new ATK tour binding with set release front and back at 170 gr.
    this looks quite revolutionary in my opinion
    at least for us european lightweight freaks!
    give a look

  39. AJ February 25th, 2010 5:35 am

    gen II tech binding

    Ski Trab TR2 perhaps?

  40. Chris March 16th, 2010 9:17 pm

    Hi Lou, you made this comment: “BTW, I’ve got some Dalbello Virus here. They’re nice boots and the metal tech fittings look good. The toe of the boot fits Dynafit binding perfectly, but the slots in the heel are in my opinion incorrectly milled and cause extra resistance at one point in lateral release. This incorrect milling is a legacy thing that’s been done on some other boots as well. I’ll bet Dalbello copied the wrong pair of boots. It’s easy to fix.”

    I have the dalbello virus boots and am mounting up some ST’s. What is the easy fix? I’m concerned about safety. also concerned since I just spent a whole bunch of $ on new boots I probably can’t return – wish I would have seen your post first.
    thank you, Chris

  41. Adam May 14th, 2010 2:29 pm

    I can’t find my Dynafit spacer thingy so I’m going with the $0.15 rule, but I’m wondering if the space of the nickels should be in between the heel of the boot and the vertical part of the binding, or should they be in front of that tiny little lip on the pins where they meet the vertical part of the binding. All this talk of fractions of MM makes me think that the space difference matters and I’d hate to get it wrong.


    BTW boots are TX-Pro and bindings are FT12.

  42. Ian December 11th, 2010 6:04 pm

    Any idea how many mm of change in boot sole adjusting the boot gap will allow? For example, will bindings mounted for a 325 mm bsl adjust to accomodate 314mm bsl boots?

  43. Jonathan Shefftz December 12th, 2010 10:06 am

    Total track length is 26mm, so in theory +/- 13mm from where they’re currently mounted if indeed they were mounted exactly in the center (as they should be).

  44. tony December 25th, 2010 9:35 pm

    Will the new 5.5 spacer that comes with this years Verticals be in spec for older Comforts? Does the new spec also apply to Comforts?

  45. Mark W December 25th, 2010 10:26 pm

    Adam, I’d recommend getting the Dynafit spacer for your binding. It’s a pain getting anything else in there for a feeler gauge.

  46. Jonathan Shefftz December 26th, 2010 6:39 am

    @tony, yes, the new spacer applies to all Dynafit bindings with adjustable tracks other than the Speed.

  47. Lou December 26th, 2010 6:15 pm

    Chris, compare to something like late model Scarpa, or better, OEM Dynafit boots, and you’ll see the difference. If necessary, the lateral clearance can be added by dremelling some shallow horizontal slots.

    Before going any farther, please review this blog post with care:


  48. Lou December 26th, 2010 6:18 pm

    All, regarding “heel gap,” don’t obsess on it (it can be 5.5 mm or 6 for the ST/FT/Comfort series, and still work fine for most people) But do use a feeler gauge to set the gap, trying to measure it with a ruler, or eyball it, is lame.

  49. Larry January 12th, 2011 12:21 am

    I recently bought a pair of Dalbello Virus Lites and love the boot. I had a pair of Scarpa Lasers before mounted with Dynift Comports(six years old). I went a shell size smaller with the Dalbello’s and now find myself pre-releasing with my right ski but not my left. The distance setting is right on between binding and boot. I’m wondering if I need to remount the heels? I was hoping not. I put my Scarpas back in the binding and reset the gap to the boot and don’t prerelease. Any suggestions? Larry

  50. Toby March 8th, 2011 2:31 am

    Question about the TLTs bump and 4 mm gap:

    TLT speeds still have that casted bump in the center of the heel piece. Just below the rear pins. The 4mm gap should be top of this bump. The actual gap between heel and the bump is something like 1,5 mm only! WHAT is the purpose of this bump? (Heritage from the original DIN certification test..??) Other new Dynafits don’t have that. Do you see any disadvantages to grind them down?

    I think that 1,5mm gap causes an unnecessary stress for the heel piece. You don’t have to load the ski much to close this gap. Real 4mm gap all the way would give a more flexibility.

  51. Lou March 8th, 2011 7:17 am

    Toby, I grind down all the TLT bumps. They’re just vestigial, were added when Dynafit tried to get TUV certification for DIN/ISO. The idea was that the bump kept the gap from closing and thus changing release values. Of lesser concern was that the bump could cause inadvertent release because it reduced binding elasticity by eliminating clearance. TUV is not known as ski binding experts, they’re just, TUV to test for a standard, for better or worse… and the DIN/ISO standard requires release values to stay within a certain range as the ski flexes and so forth. Regular alpine bindings even get influenced by ski flex, so it’s a valid concern in one sense. This is the main reason I’ll be surprised when a tech binding actually gets certified by TUV to the DIN/ISO 13992, and call BS on companies that say their bindings are “certified” or in the “process of certification. ” That said, minds way better than mine are working on making a tech binding that can receive cert for 13992, so we shall see…

  52. Toby March 8th, 2011 10:02 am

    Thanks a lot! So I did it right away. I disassembled the pins+springs for good access and used a very coarse file for the job.

  53. Lou March 8th, 2011 10:09 am

    When I grind mine off, I leave a tiny bit just so I know I didn’t mess up the strength of the housing. Have done it to dozens, no problems so far. But proceed at own risk.

  54. rod georgiu March 9th, 2011 10:05 am

    I was skiing some heavy powder yesterday, and my right boot kept coming out of the FT-12 heel, I was able to lift the heel aout of the binding while standing. Since I was in a narrow and steep couloir, this caused a lot of trepidation. I finally realized that I had snow under the brake, so I assume that prevented the pins from engaging fully.

    Does this make sense?

    Also, at the car, I found out that the vertical relase was set at 6 on that ski. (At least I assume it was the vertical release: it was NOT the setting with the cylinder that rotates.) I always set both releases at 11 and never touched them. Is it possible that the setting will go from 11 to 6 on its own?
    Or possibly the snow under the brake had something to do with it?

    I took the skis to a shop, they took the binding apart, couldnt find anything wrong with it, and they were able to adjust it to 11, clicked the boot in a few times with no problems.

    I am still spooked by this and i would apprecite any insight.

  55. Lou March 9th, 2011 10:12 am

    Two separate issue. Yes of course ice or snow under the boot or brake can mess up retention, just as with nearly any other ski binding out there.

    Setting creeping to 6 when it was 11 can result from stripped tiny nut/screw in heel unit. Just watch it carefully to see if it changes again inadvertantly. One of my son’s bindings had that problem a few years ago. Easy to fix for a binding mech, but requires attention to diagnose.

    Your binding mech said they found nothing wrong. In that case, what can I say since I can’t look at the binding myself?

  56. rod georgiu March 9th, 2011 10:15 am

    thanks Lou. I will watch it. The techs at the shop mentioned the stripped nut possibility, but they looked at it and thought it was ok.

  57. Lou March 9th, 2011 10:21 am

    Amazing the techs actually knew about that. Great!

  58. Mark O March 29th, 2011 9:58 am

    Hope this is the best thread, but here goes:

    I finally purchased some Dynafit STs to go on K2 BackUps. I bought them mail order and took them to my local ski shop in London to be attached. (They sell the bindings but had no skis I wanted). They were happy to fit them for a small charge. I took the skis touring around Chamonix and had two days of terror with many occasions of the boots coming out of the bindings, seemingly at the toe piece. (At least I got to practice that “self-arrest” technique of digging your boots and hands into the slope, several times. 🙂

    Being new to Dynafit I assumed it was my fault and I wasn’t putting them on properly – I didn’t even have a popsicle stick with me! Had I learnt nothing from reading this blog! (I used my multitool instead to religiously clear snow from under the toe piece (scratches! I know, I know).)

    Eventually took skis to a good shop in Chamonix who scratched their heads a bit and kept them over night. The next day they pointed out: bindings too loose (which could be fixed); bindings not quite in same place along length of skis; gaps at heel piece too big, one just about acceptable after max adjustment, the other not; and, probably crucially, one set of heel pins not lined up with slots in boots – meaning when forced in, always exerting lateral pressure.

    I took them back to the shop and did show and tell of the above, and left them there (as well as writing what I thought was a rather conclusive letter.) It transpires their chief technician was away when the bindings were attached and initially I had apologies and horror on their part.

    Now boss man has got involved and says it is a “component problem, not a fitting problem”. He is maintaining they were put on perfectly and there is something wrong with the bindings; he wants me to go in to be shown how perfect the holes are (they have taken the bindings off). He says the distance between the toe and heel piece holes is the same on both skis.

    Before I talk to him, I would just like to check that the fact the pins don’t line up with the slots on one of my boots is pretty crucial, isn’t it? And even if there is some mystery warping in the bindings they really shouldn’t have given them back to me like that, should they???

    Anyway, any help/advice, before I trudge along to be browbeaten,


  59. Alan November 21st, 2011 7:52 pm

    I’m a tele dude who is currently mounting dynafits, for the first time, on a plate that accepts both dynafits and 22designs axl bindings (which is pretty cool). You site as been invaluable resource for all things dynafit. Thank you!

  60. Lou November 21st, 2011 9:19 pm

    Alan, glad to be of some help! As for those plates, Dynafit marketing department should be giving them away (grin). Lou

  61. tOM November 27th, 2011 11:00 am

    Mark, IMO, YES, it is critical for the pins to be lining up with the slots in the heel. Be sure to check BOTH boots in BOTH bindings; you could have a defective tech insert placement in one boot causing the pins to “not line up”. Be sure before pointing fingers and placing blame & be prepared to walk away & take your business elsewhere. If the holes are only slightly off it may be possible to have inserts from Binding Freedom or Quiverkiller installed to correct the situation; though you’d want them installed perfectly by someone you have confidence in and is willing to stand behind the work.

    All this being said, I’ve semi-botched a binding mount where my heel was very slightly off set from the pins & had no trouble with it.

    All the best, tOM

  62. Lou November 27th, 2011 11:35 am

    Any tech binding can tolerate a very slight left or right misalignment of the heel, say a millimeter or so. But I like mine to be perfect. Generally, it’s quite easy to get perfect alignment by mounting heel unit first (to use for reference), then as you screw the toe unit down shift it left or right by placing boot in the toe, locking the toe, then pressing boot heel to left or right to slightly shift the screws as you tighten them. Sometimes, you have to take the boot in and out multiple times but it’s amazing how much most mounts will shift. Doing this process is another reason to use epoxy for any mount, as once the epoxy cures it locks in any shift you had to do.

    We’ve of course detailed the above process several dozen times over the years, but it bears repeating as it’s quite a bit different than slamming a binding on to a ski the way you can do with an alpine binding. Interestingly, however, the same process is the best way to get a perfect mount with plate/frame bindings such as Fritschi, especially if you have a worn jig or are using a paper template, and your screw holes fall ever so slightly off layout.



  63. Norseman December 1st, 2011 12:45 am

    I just got a pair of Dynafit Radical STs mounted on K2 skis. The pins don’t line up perfectly with my Maestrales for any ski/boot combination. Please see the photos below. Are any of these combinations within acceptable tolerances? What would be the best way to deal with this? I’ve mailed the photos to the store, and am waiting for their response.

    Ski 1 + left boot:
    Ski 1 + right boot:
    Ski 2 + left boot:
    Ski 2 + right boot:

  64. Lou December 1st, 2011 6:15 am

    Sigh. The place that mounted your skis messed up the work. They should fix. Did they mount using the boots to fine tune the alignment? You can also easily fix this yourself if you’ve got the correct tools and some moderate hand skills.

  65. steveG December 1st, 2011 6:25 am

    To be clear, is the fix for Norseman simply to loosen the toe screws and keep the heel properly aligned while re tightening? Looks that way to me. Maybe the tech was a bit clueless.

  66. Lou December 1st, 2011 6:50 am

    I wouldn’t be surprised if he was the victim of one of the “worst ski shops in the world,” as opposed to the best. See best here:

    But yeah, the screw loosening is the procedure. ONLY, when done after the fact all screws should be removed then re-inserted with your glue of choice, and great care taken not to strip them. If they’re loosened and re-tightened without new glue, they will not be locked or sealed from moisture.


  67. Lou December 1st, 2011 6:56 am

    By the way, there is of course a very faint chance that the boots are the problem, not the skis. But in the end, when the mount is done it should be done with the actual boots that will be used and doing so usually takes care of any small manufacturing variations in how aligned the boot fittings are.

    If a shop mounts Dynafits without the person’s boots in hand, then again, they are not doing the best job possible.

    To be fair, if they can’t mount with the actual boots (such as in the case of a mail order deal), they should at least inform the owner that the owner may have to do a final alignment tune of the binding. Problematic, but that’s the way a shop could at least keep the owner informed and achieve a final result that was acceptable.

    Just slapping bindings on without any alignment tune might work part of the time, but I’ll guarantee you’ll get a lot of mounts that way that don’t line the boots up. I mount dozens and dozens of Dynafits, have done hundreds of mounts over the years, and almost every mount requires the final alignment tune (though many end up quite close).


  68. Norseman December 1st, 2011 7:28 am

    The shop told me they would use another Maestrale boot of the same size for doing the mount. I’m gonna bring the skis (and my own boots) back to the shop tomorrow. They’ve been selling Dynafit for years, so I am expecting them to fix this.

  69. Lou December 1st, 2011 7:48 am

    Yeah, it shouldn’t be a problem if they’ve got some experience. It’s either a variation in the boot fittings, or they just got lazy and didn’t bother triple checking alignment. If they do discover your boot fittings are whacked, then you’ll need to warranty the boots. Lou

  70. Norseman December 2nd, 2011 9:25 am

    Well, I brought the skis and the boots to the store today. They couldn’t find any problems. According to the techs there, a small level of variation is a non issue, as long as the boot is able to click in, and the pins fit snugly when clicked in. So they didn’t do any adjustments, even if the lineup is not spot on. I didn’t want to argue with them, and truth is, the offset for Ski 1 + Left booth was a bit smaller in the shop than it is on my picture. Not sure what happened there.

    Anyway, I guess I’ll just go with the Ski 1+ Right boot and Ski 2 + Left boot combination, and see how it skis. If there’s any problems, I’ll take it back to the store.

  71. Lou December 2nd, 2011 9:31 am

    Why not just fix yourself? You can probably get them near perfect. Surprise the shop didn’t just fix them. Typical. Not impressed.

  72. Norseman December 2nd, 2011 9:44 am

    If I had the proper equipment, I would give it a go. Living in a city apartment, I only have my living room floor to do such work, and it’s far from ideal. I’d rather bring it to another store (there are several in my area) if adjustments are needed.

  73. Norseman December 2nd, 2011 11:17 am

    Oh, and I’m assuming that it isn’t vital that the tweak is done before the skis are used. It can just as easily be done later in the season, when the boots and bindings are worn in a bit, right?

  74. BCskier December 10th, 2011 5:44 pm

    Hi, I just bought a pair of Dynafit Speed bindings and tried to mount them on my Manaslu’s for my 310mm boots only to find they can’t be adjusted with enough room for a 4mm spacer on the recommended holes (inner set) or when I tried the toe piece on the other ski in the forward holes there was too much space. The heel piece in both cases was turned to to its maximum or minimum travel to try to accommodate the boot. Anyone have any ideas?

  75. steveG December 10th, 2011 8:40 pm

    Which holes sets have you tried? So to understand, call the front most set #1, next set back #2 etc.

  76. BCskier December 10th, 2011 10:52 pm

    Hi, I tried hole set 2 and 3 as specified on the sticker for a 310mm boot size. Result: even with the heel unit fully screwed back there is contact with the heel unit (not just the pins).

    I also tried set 1 and 3 but the problem then was too much space between the heel unit and boot even when the heel unit was screwed as far forward as possible.

    Thanks for your help!

  77. Mason December 10th, 2011 11:30 pm

    did you buy the old style speed or the radical? I thought the radical has longer pins now so the spacing should be 5.5mm?

  78. Jonathan Shefftz December 11th, 2011 7:00 am

    @BCskier, sounds like you bought the wrong bindings. Even the sticker should specify that the holes are for only Vertical and Radical bindings (along with the old Comfort). I’ve had two friends luck out with Speed bindings corresponding to their BSL, but with only +/-3mm adjustment, can’t count on it.

  79. BCskier December 11th, 2011 11:23 pm

    Thanks Jonathan and Mason. I think you are right about these old Speed bindings not being compatible with with the Manaslu’s. (except if you get lucky with your BSL) I asked the shop that I bought the bindings from if they would work on the Slu’s and they said ‘yes’. They said they will take them back, but I got them cheap and will sell to a friend and buy the speed Radicals. Thanks for your help!
    Just got back from an amazing day touring in the Monashee Mountains of BC. Great skiing in glades, steep trees, and huge old growth forest. Check out the video of us touring in this area last winter on my site http://www.skipinions.com

  80. Olaf Metal December 23rd, 2011 10:11 am

    Does anyone know what the proper gap should be for FT12 radicals?

  81. Lou December 23rd, 2011 10:24 am

    5.5, but on soft skis I’d set it as 6 because of the return of the “bump” on the binding.

  82. Lou December 23rd, 2011 10:25 am

    I just looked in the box we have here with new Radicals in it, am I wrong or have they NOT enclosed a feeler gauge with the bindings?

  83. Matt December 23rd, 2011 10:32 am

    I thought the gauge was missing in the pair of Radical I purchased, but upon looking really hard, I found the feeler gauge, same color white as the inside of the box, wedged in between the overlapping cardboard that forms the bottom of the box.

  84. Olaf Metal December 23rd, 2011 3:37 pm

    Thanks guys, this site is an amazing resource. I received mine via internet, mounted with no box. When I emailed the question to the dealer, they said 4mm.

  85. CozT December 23rd, 2011 7:53 pm

    Hi Lou & co:

    Hate to beat a dead horse here, but I’m seeking an opinion about a problem similar to Norseman’s. I just picked up my skis from a shop after a mount (Sportiva RTs with Maestrales). They had my boots for the mount. After getting them home, one boot fits both bindings perfectly. The other boot is about 2-3 mm off (to the right side in the heel) on both bindings. It seems to me that the shop mounted both bindings with the same boot.

    This sounds to me like a boot issue (as in the tech fittings are misaligned on one boot), but before I contact Scarpa I wanted to see if you’ve encountered this before. Is it common to have this kind of misalignment in a boot? If you have seen it, what have you done about it?

    Thanks for any thoughts.

  86. gringo January 16th, 2012 12:42 pm

    I was going to add this anyway, but it might be of value to you. I had a prerelease issue on my left foot for a few months, regardless of which skis I was using. After getting off the couch to do something about it, I determined that the fittings on my left boot were out of alignment which meant 3-4 mm of off-set at the heel. This meant constant preload on the toe pins and frequent prerelease. AND meant that I was skiing almost 100% of the time with toes locked…..I know , I know. …I learned my lesson when I took a short ride in a 20” deep soft slab and the skis stayed on…can you san ANCHOR?

    Anyway, I was able to warranty the boots after writing a detailed explanation of the problem. i won’t mention the name of the manufacturer because their boots fit me great and they responded well to my warranty request.
    anyway, if your boots are out of alignment, try and trade them in!

  87. scott March 21st, 2012 9:37 pm

    Lou – You might have already covered this but when setting the heel gap spacing should the ski be on a flat surface making the ski flat or should the heel gap be set while the ski is in its natural cambered position?


  88. Lou March 21st, 2012 10:44 pm

    Wow Scott, nope, I never covered that. I’d say it usually doesn’t matter, so long as the gap isn’t adjusted when the ski is flexed much either camber or de-camber position. While I advise to set the gap ‘perfectly,’ I say that more to get people to pay attention as yes, there is no perfect gap due to the ski flex changing it. Main thing would be to set the ski on a flat workbench when adjusting, not suspended between two points such as on a ski vise. Lou

  89. Omar Dickenson March 25th, 2012 9:49 pm

    Great info. Explains the problems I experienced today. I have been touring the last two weekends with my new Radical FT BD Amperage setup. In the flat heel riser mode when I flex the tail the binding seems to lock up and stick. Strange feeling! I am a Clidesdale at 205, but in four seasons on my Vertical ST never experienced anything like this. I used the new white spacer on the Radicals 5.5mm, but have always used the grey 6.0 mm on the Verticals. Guess that I will try the grey spacer on my new Verticals and see if this works.

    What is the deal with the “bump” on the front of the heel piece? Can I just file/sand this off and what is it’s function?

  90. Lou March 26th, 2012 6:33 am

    Omar, yeah, try the wider spacing. When you do so, know that reduces your RV values a bit as well as increasing your chances of coming out of the binding when the ski over-cambers, such as when doing a jump turn from a stationary position, with heavy wet snow piled on your tips and tails.

    It’s too bad they didn’t make the “stiffener plate” stiffer, as that would solve your problem as well.

    The bump is from what some call a “misguided” effort to satisfy some guy at a testing agency in Europe known as TUV. It serves no practical purpose in this itteration of binding models, and can be removed if so desired.

  91. Chris October 19th, 2012 4:37 am

    Great post Lou, thanks, was really helpful when i set my ST’s and FTZ’s:

    But I had a question re: alignement. Norseman raised it earlier and I saw your comment re loosening the front.

    My question is: at what point do you think you need to do this? I have one boot which lines up with the pins just fine (heel insert rests naturally and equally on both pins), but the other which rests only on the left pin.

    Eyeballing it, i would guess there is 3-4mm between the right pin and the left of the heel insert, and 0mm between the left pin and the right of the heel insert.

    The left pin and heel insert connect quite low – i.e. it is the rubber of the boot sole that rest on the side of left pin (not on the top) and not the metal of the heel insert itself.

    Does that sound borderline? or so you think it could be a black and white case of loosening the front and adjusting.

    thanks as always¨!

  92. Chris October 19th, 2012 7:11 am

    hmmm… read more WS posts and tried different boot/binding combinations (i have some skookums and some TLT5s on ST and FTZs, mounted on some movement logics and movement trusts).

    i ended up cycling every combination possible (both pairs of boots on both pairs of skis, with boots swapped on each ski every time).

    the conclusion surprised me:

    on the BIG SKIS with the FTZs, i found that a specific boot with a specific ski would work and rear pins would align with a tolerance of less than 1 mm off center.

    BUT: he proper alignement I got with for the Dynafit boots was the opposite to the one I got iththe Scarpa boots (i.e. on one ski, i would get a good fit with the left Dynafit and the right Scarpa, but the right Dynafit and left Scarpa would not fit properly on that ski. The reverse would be true for the other ski)

    On the LIGHT SKIS with the FTs, i got no proper fit at all with any of the boots. More suprising, is that both the scarpas and the dynafits (both L and R) “misalgned” in the same way by roughly the same amount!

    There are too many potential combinations of left, right, dynafit, scarpa, ST and FTZ for my pea brain to grasp. I am sure some of the 8 bindings (4 front and 4 rears) have been misaligned in some way, and, possibly, that some of my boots have minute differences in insert geometry (e.g. there is a 5mm difference in their BSL, but roughly only a 1mm adjustement tobe made in the Tech Gap).

    Just thinking about alll these combinations makes my head spin – ill just go with the Lou method: start with a low DIN, ratchet up until pre releases stop, and if that ends up being above 9 (the number I have always used), ill get someone who knows what he is doing to fix it!

  93. Lou Dawson October 19th, 2012 7:27 am

    Whew, my head is spinning as well! Main thing with trial and error method of setting Release Value (RV) is to start high enough so you don’t get hurt taking a bunch of falls. I recommend starting with what the chart says.


    There is a DIN chart on this post, I should move the chart somewhere more current (grin).


  94. Linas November 21st, 2012 8:44 am

    Hello, I noticed your < FAQ states “After 2009/2020 sales season all Dynafit bindings will use a 5.5 mm gap”. Assuming 2020 is supposed to be 2010, can you confirm that statement is wrong? Meaning, the TLT/Speed/Race bindings are still using the 4mm gap today as stated in the comments of this article? Thanks in advance for clearing this up.

  95. Lou Dawson November 21st, 2012 9:32 am

    Linas, the statement is correct. All Dynafit binding models made after 2010 use the 5.5 mm gap. I do not have a Race here to evaluate, but can confirm that all Radical series _including_ Speed use the 5.5 mm gap! Reason is they all have the slightly longer heel pins.

    (The Vertical ST and FT also use the 5.5 mm gap.)

    I will edit the FAQ to fix that typo.

    As for the Race bindings, just contact Dynafit, but they told me specifically that _all_ their bindings use 5.5. However, it is possible they were not considering the Race model.


  96. Tony Mikhael December 8th, 2012 7:14 am

    Hi Lou,

    Out of all places in the world where people think there is no snow and lots of sand…I am contacting you from Lebanon where last year I was able to rando ski for 5 month (Early Dec to late April) … I hope you are doing well 🙂

    I need your help/opinion on something: I just bought a new TLT5 Mountain boot on a trip to USA and brought it back with me, and naturally given the shorter boot length compared to my older boot it required repositionning my TLT Speed bindings on my 7Summit 170cm skis. Given lack of a dynafit binding jig my local ski tech did this job by using the old drill holes and actual measurements for reference to install it.

    My questions:

    #1- Assuming the old holes were exactly centered for Ski/boot, since it was originally done in USA by a professional dynafit tech, the tech here told me he could not install the TLT Speed exactly centered for the Skis because the new drill holes would be too close to the old ones. So he gave me a choice of Off-centering towards the front or to the tail. He advised me to off-center to the tail for better flotation/handling in off-piste/powder, since on-piste I am a good skier, it wouldn’t matter as much. This is how my boot sits now : Ski tip to boot tip 83.3cm + Boot is 28.7cm + heel to ski tail 58cm. What’s ur take on the positioning?

    #2- Is 1.4 cm a safe gap between old holes and new holes?

    #3- After reading some of your notes. I am not sure if my TLT speed binding are with the newer/longer prongs or older style, since I bought them in 2010, they could have been an old stock. So I am not sure how to adjust the heel Gap accordingly. The length of the prongs are 11 mm, does it make them new or old?

    #4- Thinking I could use my TLT speed binding with my old boot (occasionally, especially if I am doing a downhill only ski day, since my other boot is much stiffer), I told the tech to install the bindings at the lowest/closest adjustment setting, but leaving me a max 2mm adjustment for the heel gap. Well he missed this part and installed the heel binding at the closest setting, leaving me no room to adjust the heel gap any closer.
    My right side gap when boot is locked in, and skis flat on floor is 4mm
    My left side gap however is 4.8mm. I can barely squeeze in a Nickle between the boot and heel binding (over the bump). I cannot adjust it any closer it’s at it’s max now.
    My heels are perfectly centered on the bindings

    Do you think this is going to be an issue?

    Thanks in advance. (I also sent you an email with the same question my apologies for the redundancy)

    Tony Mikhael

  97. Lou Dawson December 8th, 2012 8:29 am

    Hi Tony, I’m surprised neither you nor the binding mounter simply downloaded a paper template, such as the one available at


    I mean, Google exists, but perhaps not in Lebanon?

    #1. Ok
    #2. Ok
    #3. Measure the prong/pin from the front side of tiny metal flange, longer pins are 11 mm in that measurement. Most “Speed” model bindings have the longer pins, but no way for me to know exactly what binding you have.
    #4. Regarding heel gap, I can only recommend that you use the correct one. Too many variables for remote viewing of your situation. Know that the heel gap influences everything from pre release to the actual release values. Too close can damage the binding. Too close OR too far can cause pre release.


  98. Lou Dawson December 8th, 2012 8:32 am

    P.S., my binding mount instructions and template do lack the word “Speed” so perhaps it was unclear to you guys that you could have used that template. I’ll fix that today. Lou

  99. Tony Mikhael December 8th, 2012 10:32 am

    Thanks Lou. No we have google out here 🙂 I should have done my homework before the fact, not after the mistake is done, but the tech was very reputable and pretty confident he was up to the task, so i never questioned the judgement. Although he was not familiar with installing dynafit bindings. He did sketch out the hole pattern and was very precise moving the holes over. I think the minor difference in the holes between both skis was previously corrected with the gap adjuster, but given that he “understood” from me that I wanted the adjuster maxed out, once they were installed, we no longer have that flexibility to tighten that gap….so now at the maximum tightness I have 3.9-4 mm on my right and 4.8-4.9mm on my left.

    My pins are near 11mm without that flange you are referring to, and about 11.6mm with it or from the vertical side surface they come out from the binding housing. So if they are the new type does it mean my gap should be 4mm or 5.5mm? and if it 4mm. What do I do at this point with my right gap since it’s 4.8mm? I cannot re-drill a third time 🙁

    I had forgotten question 5 previously: Do you know that little washer at the other side of the gap adjustment screw, while trying to max it out we over tightened it and the screw “slipped” out of the washer. Obviously it was originally pressed to create a small edge to prevent this from happening, so he repressed it, and told me that he’s fixed similar problems many times on different bindings, so it’s as good as it was, and safe to ski. Have you seen this happening? Are we good on that end?

    My thanks

  100. AT Newbie January 5th, 2013 12:00 am

    Thanks for all the great info on this site. I’ve been an AT wannabe for some time and took the plunge unexpectedly when my local shop had some barely used demos for sale – K2 Waybacks with Dynafits Vertical STs. I’ve done a lot of resort skiing but AT bindings are new to me so I am getting comfortable with how they work before I take them out.

    Here is my question: I need to adjust the heel piece on my findings to fit my boot. I’ve read this great info about the tech gap but my bindings don’t have the same looking screw at the back of the baseplate. Mine is more like a bolt – no screwdriver slot, just a flat bolt. I imagine I could turn it with a wrench but that would likely chew up the bolt. Is that still the way to adjust the length of the binding? I don’t have the spacer so I will need to use something that’s 4mm (based on what I’ve read that’s the right gap) or go back to my shop to get one.

    Thank you!

  101. Lou Dawson January 5th, 2013 9:28 am

    AT, you might have a rental binding, which has a bolt head back there instead of a screw head. Simple, just use a socket on a nut driver shaft if that’s the case. Actually works better than the screw head type, as it won’t get damaged. Lou

  102. AT Newbie January 5th, 2013 3:59 pm

    Thanks Lou. That confirms what I was thinking. Very helpful as now I can mess around without worrying that I am changing something I don’t mean to.

  103. Lou Dawson January 5th, 2013 4:34 pm

    Main thing with the length adjustment is don’t force it at either end of the range, as doing so can damage the binding.

  104. Shawn January 25th, 2013 1:22 pm

    With a radical FT do you measure 5.5mm above the bump? Or insert the spacer below the bump to measure 5.5 from the front of the bump?

  105. Chris January 27th, 2013 6:35 pm

    I’m a little confused about the range of dynafit bindings. I have some pre radical (vertical) st10’s (new in about 08 I believe). I have both a Zeus and a tlt5 boot–the Zeus have a bsl of 312 and the tlt5 is 297. I would like to mount the st10s so that I can use both boots but I’ve been told the range is anywhere from 12-15mm. I obviously would like to avoid double mounting if its not possible to do this. Anyone have experience with this kind of range issue? Can I figure it out definitively before I get the mount done? One Shop told me it would be very close. If it can’t be done, I’m just gonna set them up for the 297 tlt5, but I’d like the option do both. Thoughts?

  106. seth February 5th, 2013 3:03 am


    I just got a new pair of skis with radicals and they came with a different sort of plastic gap gauge for setting the boot spacing. The gauge has two oval tabs at each end that hold a sort of elliptical leaf spring in the middle ( I could email a photo to anyone interested). One of the tabs says up. I was unable to find any info on this gauge on the web so I called up the shop I ordered the skis from and they confirmed it was a new style gauge. The info I got from them was that you just use it as a gap gauge without compressing it at all. This sounds okay but to me the fact the gauge can be compressed implies there is a range of acceptable spacings. You could either compress the gauge fully for a tight fit or have it uncompressed for a loose fit. I was hoping someone else has seen this and can give some additional details.



  107. Lou Dawson February 5th, 2013 6:21 am

    Seth, like any engineered machine on the planet, the gap at the heel of a tech binding does have a tolerance range. In my experience it’s up to a millimeter. Not sure about the new gauge, I’ll have to get one and fool around with it. Those guys at Dynafit sure keep us hopping here (grin).

    Email us a photo and I’ll post here. Use contact link above. Try to make a photo that’s sharp and turn off your camera flash. Try macro mode without flash.


  108. seth February 5th, 2013 12:00 pm

    Hi Lou,

    Thanks for the response. I just emailed you a few photos of the gauge. I didn’t have a caliper around to get an accurate measurement but with a ruler it appears to have a range of 4 mm compressed to 6.5 mm open. Looking at it again, I’m now thinking that the gauge is meant to be compressed between the boot and the binding until these 3 teeth like protrusions on the top of the gauge line up. This would occur at about the 5.5 mm mentioned in this article. If this is the correct way to use it then maybe the intention is to take a bit of the subjectivity out of what a snug fit on a gap gauge is. Anyway, it’s quite the elaborate looking thing so it would be nice to know how Dynafit recommends using it.



  109. Ryan February 13th, 2013 9:00 pm

    Wanted to check in with you about this. I was reading about setting my FT 12s and the spacing for the heel and saw this bit about the milled out lateral/horizontal channels to either side of the tech fitting on the Dynafit boots. I ski on Megarides and they do not have those channels. The safety release is anything but smooth and part of that is from the pin hanging up on the plastic around the pocket. My question is would the Megaride heel be robust enough to have this material removed and still work with a non-tech fitting if I was swapping between each of them. Would be interested in your thoughts….

  110. Matthew Volkman October 12th, 2013 6:46 pm

    Question for Lou,

    For some reason when i received my last pair of radical FT’s this was not in the box. Do you know how you would o

  111. Matthew Volkman October 12th, 2013 6:48 pm

    Question for Lou,

    Sorry for the double post :/

    My last pair of Radical FTs did not come with the gauge to measure space between boot and back of binding. Do you know the best way of going about obtaining one of these gauges? Is Dynafit’s Customer service helpful? I’ve never worked with them.


  112. Michael Finger October 12th, 2013 8:07 pm

    Dynafit has been great every time I’ve called. Also, as Lou notes about you can use 3 stacked nickels, or I use a 5.5mm allen key that you can buy at Loew’s, etc.

  113. Lou Dawson October 13th, 2013 3:38 pm

    Thanks Michael!

  114. Ryan McCall November 19th, 2013 3:21 pm

    I am willing to bet this was covered somewhere at some point, but I can’t find it for the life of me. Anyone grind off the bump on the TLTs/Speeds for a little more clearance on the pins? Does the bump serve a purpose, it is reducing the amount of plastic internally that could cause some spring to explode out of the binding?

    Obviously it would make sense to use the 4mm spacer still, but with the bump gone I’d think I would effectively lessen a pre release in a trough or crossing a gully.

    What do you guys say – anyone do this with success?

  115. Lou Dawson November 19th, 2013 7:40 pm

    Ryan, I always grind the bump off the older TLTs. It’s totally unnecessary and is vestigial to a long ago effort at TUV certification, idea being that it blocks the binding from closing up during ski flex so the release value has less change. When I grind them off, I leave a half mm or so of material so as not to grind into the binding housing. Have done dozens on older TLTs and , never had one explode.The Speed doesn’t have a very thick bump, does it? I’m up at WildSnow Field HQ and don’t have one up here to look at. Grind away, but leave a bit. Lou

  116. Ryan November 19th, 2013 7:51 pm

    Man, fast turn around Lou! Thanks.

    Nope the Speed bump isn’t nearly as pronounced as the older TLTs, so should be quick work to get it down to the 1/2 mm protrusion.

  117. Daniel Michel December 23rd, 2013 3:18 am

    Just used one of the new gauges to adjust the gap on my new Radical ST, and I think you got it slightly wrong on how to get the right distance:
    As far as I can tell, the idea is not that you close the gap until the gauge is completely closed. When the three small adjustment tips on top of the gauge are in a row, the gauge measures exactly 5.5mm. This is also why one side of the gauge is labeled “up”. Using the gauge like this, one can easily see whether the gap is too wide, too narrow, or just right.

  118. Mark January 12th, 2014 2:05 am

    Hi Lou, there are so many comments on this page I’m not sure this is completely relevant but here is the result of some practical field testing rather than theory and bench testing.

    I tore the toepiece of my FT12s out of the ski on day one of a 14 day ski tour. Remounted forward (only option on the Manaslus) and with rear binding screwed all the way forward the two heel pins only just penetrated the depth of the metal heel piece on my Green Machine boots. I toured for 13 more days like this and never popped out. I got home and skied bumps to test them and never popped out.

    I have just binned the skis and was re-checking what the real gap should be for the new ones, but my comment is that in practice there is clearly a lot of tolerance in the system.

  119. louis dawson January 12th, 2014 4:25 am

    Mark, super observations, I agree that the heel pin system is quite something. Much of what is going on is fixing what works .

  120. Greg January 15th, 2014 1:29 pm

    Hello Lou,

    Stupid question but should Vertical ST bindings sold and manufactured prior to when the 6mm to 5.5mm gap change happened be set at 6 or 5.5mm?

    In other words, and given that the heel pins have the same length for all Vertical bindings (pre and post 2010) if I understand correctly, were the release springs strength of the Vertical adjusted post 2010 to adjust for the half mm gap change?

  121. louis dawson January 15th, 2014 1:37 pm

    My understanding is that the gap was changed only to make the numbers more accurate. Use what works.

  122. John Baldwin October 5th, 2014 11:34 am

    Great website Lou!!
    I was changing boots on a ski and needed to check if the bindings would adjust enough to meet the heel tolerance. Found exactly what I needed to know, Thanks for the fantastic resource you’ve created!!!

  123. Peter November 20th, 2014 8:35 am

    I have a ski set-up with TLT Radical FT bindings. I have just bought new boots (Scarpa F1 Evo), and unfortunately the sole length for these is shorter than mý older Scarpa boots (same size 27,5).

    The adjustment of the TLT Radical FT only allows me to get a 7 mm gap at the shortest setting of the binding. This is enough for pin penetration of both the regular heel piece as well as engaging the special locking mechanism on the Scarpa F1 Evo boots.

    However, my question is, is there a way to modify the adjustment track on the binding to allow for an additional 1-2 mm of shortening? I was thinking that there may be some plastic stopper that I could shave off 1-2 mm or perhaps heat it with a focused flame and tighten the binding into it?


  124. Lou Dawson 2 November 20th, 2014 9:06 am

    Peter, I wouldn’t recommend that sort of mod. What you should probably do is remove the heel units and mount them farther forward, at the spot where they work for both boots. Lou

  125. Peter November 20th, 2014 9:31 am

    What is the minimum recommended spacing between screw holes for a new mount?

    If I screw the binding slider screw very tight I can bring down the gap to 6 mm. Do you still recommend moving the binding?


    P.S. Thanks for a great and informative website!

  126. Lou Dawson 2 November 20th, 2014 10:20 am

    Depends on the style of skier, weight of skier, model of ski, type of binding, and so on. I’ve done everything from overlapping to going a centimeter apart. Centimeter is a good rule of thumb. If that’s too far for you and you’re not the type of skier who yanks binding off skis, just go to the point where the new holes are at least 3 mm from the old holes, and fill the old holes with 1-hour epoxy.

    In terms of recommending moving binding, you have to run tech bindings at the correct heel gap, not doing so creates problems.

  127. Peter November 20th, 2014 11:21 am

    Is there anything preventing me from movind the toe piece instead? The skis are Rossignol Super 7’s and I would rather be behind the center line than in front.


  128. Lou Dawson 2 November 20th, 2014 12:52 pm

    Peter, that’s better. Lou

  129. Daniel Waeger January 13th, 2015 3:16 pm

    Just got a “new” boot (TLT 5P, slightly used) and adjusting my binding: TLT Vertical ST, as in the pictures above. Of course I don’t have the spacer any more, but figured out that a 5mm Allen key is just the right tool: Side to side measurement is, of course, 5 mm and corner to corner across is 5.6mm. So, you shouldn’t be able to fit the Allen key in diagonally

  130. Joefbtg28 February 3rd, 2015 9:34 am

    So I just realized, after reading this article, that the shop set my heel gap to 4mm on Radical FT’s. No wonder I haven’t released from those bindings yet! Set them properly with a caliper last night.

  131. Tom O March 8th, 2015 3:56 pm

    Hi Lou
    Just has my radical st 2013/2014 bindings remounted on some new skis. I notice this year, when using the high heel riser that the bindings move back a few mm each step and one of them clicks with each step. These bindings have the heel elasticity in them. I never noticed this last year when I had them mounted on a different pair of skis. Is this normal? I just checked the spacing in the heel with the little plastic gizmo and it looked good. Any ideas? Usually only happens on one ski also. Anything else the shop forgot to adjust with the new mount?

  132. Lou Dawson 2 March 8th, 2015 9:07 pm

    Normal. They move with each step. Not sure about the clicking, that would concern me.

    Thanks for reminding me to update this post with latest tech gap info.


  133. Rick December 14th, 2015 8:41 pm

    On the new ST 2.0 heel, there is a small protrusion of plastic that runs along the same plane as the bottom of pins. It can prevent the plastic shim from sitting on the pins.

    Am I correct in adjusting the heel gap by making sure that the plastic shim sits on the pins, or is the correct gap produced by sitting the shim on the “ledge” I described in the first paragraph of my post?

    I have a good photo of this if you are interested Lou.

  134. Olivier March 22nd, 2016 5:33 pm

    What about the gap for radical 2.0? mine came from the ski with almost no gap and I read somewhere that it should be 0.15 mm… your take?

  135. Lou Dawson 2 March 22nd, 2016 6:19 pm

    Just so you can see some light through it, we’re calling it the “kiss gap.” Main thing is it is NOT tight or even compressed against the boot, very easy mistake to make as lots of skiers are in the habit of turning all adjustment screws to “11” because that means they are a better skier, or something like that… It’s actually a bit tricky to adjust the 2.0 gap, as the sliding spring loaded heel unit can be a little sticky, I find myself wriggling it with my hand and tapping with screwdriver handle to make sure it’s in its resting position.

    Reminds me, I’ll add a photo to this post.


  136. Courtney May 2nd, 2016 11:15 am

    Hi Lou,
    Curious about a hybrid concept. Is it feasible to pair a Radical 1 heel with a Beast 14 toe?

    Does the pivoting toe require the kiss heel interface (not supported by the Radical 1)? Or could it work at 5.5mm heel spacing?

  137. Lou Dawson 2 May 2nd, 2016 12:50 pm

    Hi Courtney, it would probably work in theory, but you’d have trouble getting enough lateral release tension as well as the ramp angle probably being pretty different. To the best of my knowledge the kiss gap interface at heel, or not, would make no difference other than the fact that the kiss can prevent a certain kind of pre-release (over flexed ski causing binding to push hard on heel of boot). You’d also need the Radical 1 heel with all the upgrades, as a matter of principle.

    Can you be more specific about what you have going on? Spare parts? Or a specific goal in binding performance?


  138. Pablo August 23rd, 2016 4:57 am

    and what about the opposite to heel gap?
    How many mm do you consider as the minimun safe pin insertion?
    How many mm can prevent to “take off” when ski decambered?

    what could be “the perfect” pin insertion?
    X? mm in / X? mm gap


  139. Lou Dawson 2 August 23rd, 2016 7:30 am

    Hi Pablo, there is no exact number. The more flexible the ski and the longer the boot, the more likely “reverse camber” of the ski will pull the pins out of the boot heel. Style of skiing and size of skier also come into play. It’s an inherent design factor in the classic tech binding heel.

    (Bear in mind this issue we are discussing is inherent to “classic” tech bindings that do NOT have the heel unit mounted on a spring loaded track system that allows the binding to move forward and back. Bindings with the spring, that are set up with a “kiss gap,” only require that the cavity at the heel fitting be deep enough for the pins, and that the boot can be released to the side at the heel during bench tests, without catching or being obstructed.)

    What I recommend is
    1. Use boot with at least a 12 mm deep heel socket, which not so coincidentally is deeper than virtually all tech binding heel pin lengths. If the boot does not have adequate depth, modify by drilling deeper or using a heel fitting such as the Atomic as suggested above, or Dynafit Beast.

    2. Set binding using manufacturer specified heel gap and test in workshop. Test regular release functions with best method available.


    3. Test performance during ski flex by bending the ski in the workshop and observing interaction of boot and binding.

    4. Consider your style of skiing. The classic “pin” type tech binding heel has inherent design limits. Using a heel with forward-back spring action or even a non-pin heel interface (Marker Kingpin, Dynafit Radical later versions, G3 ION, Beast, Vipec, and so on) may be essential to preventing accidental release due to ski flex.

    The philosophical issue here is we continue to ask classic pin bindings with a 30+ old design to behave like our modern alpine bindings. The classic pin binding is amazing, that’s why it’s still being made. It is a stunning combination of function and efficiency. But it lacks allowance for “travel” and “elasticity” that some skiers might need. Alternatives to the classic tech binding exist, enjoy if that’s what you need. Otherwise, as it does for literally hundreds of thousands of ski tourers, the classic tech binding will work for you if set up properly with attention to details such as the depth of the boot heel fitting cavity.

    Another thing I’d offer here is this is an example of just how technical ski touring bindings have become. Do it yourself is wonderful, and we recommend giving it a go if you have the hand skills and some ability to logic through how a ski binding works, but we feel that an experienced technician who handles hundreds if not thousands of binding setups could often be a better person to tune your tech binding setup. The problem is finding that person, as ski shops are notorious for having beer soused mechanical idiots in their back rooms, posing as “techs.”

    This link can help, but be careful.



  140. Lou Dawson 2 August 23rd, 2016 9:11 am

    Pablo and all, I keep making changes and additions to this post — and it’s got excellent comments due to your attention. figured I should bring it up to the front for a day. Enjoy.

  141. Pablo August 23rd, 2016 10:25 am

    As always Lou, Thanks!

    As you say, there are a lot well formed engineers behind bindings desings. And the way to have the best performance for it’s bindings is to follow their operation guidelines.

    But, we are skifreaks and always tend to go further in search of the holy grail of bindings. Even if this means to try frankenbindings or extrange binder-botts combos. It’s kinda drug for us to try and try…and having so much fun and getting more and more Knowledge about skiing Stuff.

    It’s a pleasure to have wildsnow.com as a place to great skiing stuff discussion.

    Thank you.


  142. Andy Carey August 23rd, 2016 7:27 pm

    Probably will get lost here with all the comments–a little off topic. The gap on Plum is smaller and the pins are longer. I had to grind out the pin slots on my TLT6s and Mercuries to get the gap right and to avoid problems of not being able to lock the heel down in the snow (lower temps)–where I had to move the heel back from my bench settings.

  143. Lou Dawson 2 August 24th, 2016 5:01 am

    Andy, not off topic at all, Plum demonstrates how variable the tech gap and pin length can be, and the reason the slots/holes in heel of boot need to be quite deep for the system to work optimally, i.e, with sufficiently long pins and a reasonably wide tech gap, in the case of fully classic tech bindings that do not have a spring mounted heel unit that can move forward and back.

    It’s worth mentioning that long pins, deep boot sockets and a wide tech gap can be very adequate in allowing ski flex. I’m impressed by the engineering behind some of the spring enabled heel units that help compensate for ski flex, but one has to admit that Barthel’s original idea is genius in its simplicity. I don’t think it’s going away any time soon. Weighs less, costs less to make and probably breaks less. The trinity?


  144. Vitaliy August 26th, 2016 11:31 pm

    Hello, Lou. Do you know gap length on Salomon Mnt tech? I bought used ones without leash (they use it as a spacer) and want to remount them. It seems like 2mm? By the way Salomon mnt explore skis paired with Salomon tech bindings are really awesome. As for me they ski better than Denali and Vipec, my senond pair.

  145. Martin November 7th, 2016 9:03 am
  146. Todd December 5th, 2016 4:44 pm

    I’m possibly going to update my boots and what I’m looking at has a shorter boot sole length by 10-15mm. On one set of skis I have a Dynafit Radical ST 1.0 & on the other skis the newer Radical ST 2.0. Sounds like this change is doable without remounting the binding but my question is will different position of the boot on the ski change how the ski performs or skis in any noticeable way?

  147. Lou Dawson 2 December 5th, 2016 5:57 pm

    Todd, depends on the ski and other ergonomic factors. For example, if you’re already mounted a bit back on the ski, then a boot swap brings you even farther back, then it might be detrimental, but the opposite can easily happen! I’d just try it, only way to really tell. Lou

  148. Todd December 5th, 2016 6:15 pm

    Thanks Lou. The older binding is on a K2 Coomback (the older 102? underfoot) and newer is a Voile V8. Both are mounted “boot center” I believe. Never really have understood why one would mount forward or rear of that and have gotten opposite explanations in the past! Like your advice of just trying and see if I notice any difference. I’m assuming if I end up with a boot that has a shorter length and move the heel piece forward to accommodate that I’ll end up with a mount that’s forward of boot center. Obviously I’m not an engineer!

  149. PieterG December 6th, 2016 3:29 am

    @Todd: if you are currently mounted at bootcenter and you opt for a shoe which is 10 mm shorter and only move the heel piece of your binding, your shoe’s midsole point only shifts 5 mm towards the toe.

    From what I have read (never tried it), it’s hard to notice being 5 mm in front of your midpoint.

  150. Lou Dawson 2 December 6th, 2016 7:59 am

    Hi guys, I’ve experimented for years with boot position on ski, I agree, 5 mm is not usually noticeable. Lou

  151. Al January 7th, 2017 2:57 pm

    Hi- I just got back from the shop where I was charged 70$ to mount some st 2 bindings. Two things: the first is they didn’t know about the kiss gap. They showed me the gap using a piece of plastic at least 2mm thick marked “dynafit”. Clearly left over from earlier models. Reading here and other sights I used the tiny gap of light to adjust the forward pressure. Second, the skis were mounted on the mid boot line. I’m stunned at how forward they are compared to some dynafit skis from the pre drilled holes era. We’re talking inches. Oh well, well see how they ski. Best to learn about your bindings is the take home I guess.

  152. Lou Dawson 2 January 7th, 2017 3:34 pm

    Well, the shop is supposed to cut through the confusion, not add to it! As for the mount price, that seems reasonable if it’s done well. As for position on ski, yeah, it’s about how they ski, not how they look. Lou

  153. Al January 7th, 2017 4:14 pm

    Thanks for the reply. I don’t mind paying for service. It is less satisfying when I get home and starting messing with the bindings are realize they aren’t set up correctly. Otoh, I think I know, at a minimum, what I should about the 2.0. I think. Here is something else. In videos and looking around the web it seems some of these bindings only rotate in one direction, but others (mine for example) rotate clockwise 90 deg (skier view) for uphill, but back to the center 90 deg counter clockwise for ski mode. In other words they rotate both ways 90 deg. Have I missed something after all? Thanks

  154. Todd January 7th, 2017 5:34 pm

    @Pieter, Lou, Al
    I did end up buying a boot with a shorter bsl and did adjust the heel piece of my dnafit st 2 forward. Don’t notice any difference in how the V8’s ski. Al, yes the 2.0 heel piece does turn clockwise and counter clockwise unlike the previous 1.0. I also find our local shops mixed in terms of competency and often I seem to know more about a product than the shop, though really depends on the individual, and my knowledge is pretty basic! A bit frustrating at times.

  155. Lou Dawson 2 January 8th, 2017 7:27 am

    Todd, I’d agree that what you encounter in a ski shop is most certainly based on the employee you interface with! Some shops overall seem to have better trained and knowledgeable employees, and better attitudes. But it’s hard to get 100% best results. Human factor and all that. I worked as a sales clerk in retail for a while in my very younger days. I was most certainly a jerk at times, though I remember sincerely trying to help people as well, when I was in the mood, anyway (smile). Overall, I’m not proud of how I did there, I was way too immature and so on. Lou

  156. Al January 8th, 2017 7:58 am

    I agree, much of your experience in any service or sales situation depends on the person you deal with, but that’s the whole point of going to a brick and mortar store. If I have to go on line (which the employee should surely be able to do as well as an old man) to make sure things are done right- why go there at all? Of course we’re all responsible for ourselves so there is a an upside. Plus it’s fun and informative to go to a site like this one and get more info and ideas. So, thanks to you all for helping me expand my knowledge base- which we all need to do anyway. The good news. 4″ last nite, and more on the way here in central Idaho and I think my new set up is ready to go!

  157. Al January 8th, 2017 8:27 am

    Ok. Last group question. Seems new boots come with an improved power strap. I have tlt6s with a Velcro strap. A rachet buckle would be better (no snow build up, better tightening power). Has anybody come up with a retro fit for adding a buckled power strap to replace the oem Velcro one? Thanks

  158. Lou Dawson 2 January 8th, 2017 8:53 am

    Yeah, lots of people come up with various power strap options, so as to make it easy to tighten like crazy. Thing is, the power strap while clearly useful isn’t intended to be another boot shell buckle, if you need to tighten it that much you might look at your overall boot fit, as well as how your type of boot suites your style of skiing. Generally, the 2/1 mechanical advantage of a strap running through an anchor-buckle-loop and doubling back, as most do, should be good enough to integrate shell-liner-leg at the upper cuff level

    Or, if you mean “buckled” in the simple sense, note that many power straps already use a buckle instead of Velcro. Dynafit, Salomon… is that all you’re talking about?

  159. Todd January 8th, 2017 9:02 am

    Haha! I think the only time I added a buckle like that was over 25 years ago to a pair of tele leather Merrill double boots! Last boots, Garmont Radiums, and new boots Maestale RS are stiff enough just using the OEM top buckle and power strap.

    Agree that if going to pay more (sometimes significantly) in a brick and mortar I expect knowledge and expertise. Not that folks aren’t friendly, they usually are, but often they’re low wage employees with minimal experience. And more and more, what the brick and mortar can afford to stock in multiple sizes is becoming limited. I really feel for the small independent retailer; it’s a really tough market. If they want to survive, however, I think they’ve got to have enough key people employed to offer both expert sales and service.

  160. Al January 8th, 2017 10:07 am

    The power strap works ok, but the Velcro gets snow packed and looses it ability to stick and be tight at all. I’m pretty sure my shell size is good. Toes bang the front with one finger (minus liner). Couldn’t get foot in on the next size down. Tlt6 “27” and I wear a street size 10.

    I’m aware of the problems b and m places have with costs, the Internet etc. problem is, where I live, I walk in and if I’m not drinking an 8$ latte and wearing Patagonia stuff with the tags on it, I’m ignored or talked down to. The snob situation is infuriating. As the women where I work say about shopping here, ” you can get better, but you can’t pay more”. Anyway, enough of my whining about retail. I’m going to Jackson next week and I’ll go to “Teton mountaineering” and spend money but get value for it.

  161. JohnJ December 12th, 2017 1:54 pm

    Lou, I am mounting some speed radicals, and though I had mounted many comforts and TLT’s over the years, I had questions about these. Your site has answered all of them so far except one, so here it is:

    These bindings came with the new style gap gauge that has the three tabs that must be aligned while it is squeezed between the binding and the boot heel. In the photos above, that gauge is shown sitting on top of the pins. In another photo, some earlier gauges are shown along with a digital caliper. Two of those gauges (including the 5.5mm one, appropriate for radicals) have a shoulder that would rest on the pins, allowing a part of the gauge to extend below the pins. Another photo shows that this is how that gauge is used.

    The face of the housing has a raised area on it about a mm in height that is below the pins. It is clear that using a gauge that contacts the raised area would result in a different gap from what it would be if the gauge was entirely above the pins.

    Do you have any comment on this? What is your recommendation for a specific technique to use the gauge I have to set this gap? Thanks.

  162. Lou2 December 12th, 2017 2:54 pm

    The white gauge shown in photos is supposed to rest on top of the pins. Lou

  163. JohnJ December 12th, 2017 8:32 pm


  164. Aaron January 28th, 2018 9:34 am

    Lou – do you know of a place I could buy a replacement 6 mm feeler gauge for a pair of Verical FT’s from 2007/8? I finally lost mine last winter. Thanks!

  165. Kyle February 4th, 2018 1:34 pm

    If your using the 5.5gap and measuring it with say the Allen key which I have, should it measure from the top of the pins or from the raised circle bump underneath. Similar to above question but wondering if it’s different when your not using the white clip.

  166. Lou Dawson 2 February 4th, 2018 2:27 pm

    Kyle, a half a mm either way is the tolerance we work with, so measure from above the pins or top of the bump, using 5 mm and don’t obsess (smile). The gap changes all the time while you’re skiing, what this setting does is set it at a sort of in-between so the gap can open and close correctly.


  167. Kasper February 15th, 2018 11:12 am

    I just had an ATK Haute Route mounted by a shop. Unfortunately, they didn’t get the gap quite right. ATK specifies 4 mm and the shop mounted them with 6-7 mm. This binding doesn’t have any adjustment range. The pins from the binding enters the heel insert on my boot to the depth of the thickness of the steel-part of the heel insert, but not farther. In other words, the pins just cover the steel part – but only just.
    What kind of problems could this result in? Is it possible that the pins could pop out of the insert during skiing or would it “only” result in easier release (in which case i could just set the release setting a bit higher)?

  168. Matus February 15th, 2018 1:06 pm

    Kasper, definitely not good mounting and I would not recommend skiing with such a setup. High risk of popping out of the heel. Did they use original ATK jig? Probably not. I wonder how they are going to fix this…but the consumer right is in your side.

  169. Kasper Berkowicz February 15th, 2018 1:20 pm

    They did use an original atk jig. They want me to ski them for a day to see if they release to easily. If they do, they propose to remove the heel piece, plug the holes with metal plugs and attempt to redrill the ski (Scott superguide 95). The holes will be very close though.

  170. Kristian February 15th, 2018 3:02 pm

    So, I buy and mount all of my ATK bindings with an adjustable plate because this super tight tolerance stuff seems so fraught with potential issues. And to be able to switch to different boots. Worth the few extra grams to me.

    You can find ATK adjustable plates online in most countries including the USA. Might be a better option then re-drilling almost the same holes.

  171. TimZ February 15th, 2018 3:45 pm

    I also mount with adjustment plates. I would ask they buy adjustment plates and remount with that. It is possible to remount with a few mm difference, but very close and not nice.
    I did a race heel mount 3mm different once, but It’s not very pleasant

  172. Rudi February 15th, 2018 4:37 pm

    Kasper are you flexing the camber out of the ski when you take this measurement? the ski will have too much gap until you step into the binding and your weight decambers the ski. this may pull the gap back into spec. otherwise if it is still off, first id be pretty angry then id calm down and go to a +1 mount. it wont make you suddenly start sliding rails it will just make the ski a bit quicker. i do it to all touring skis as they have excessive tip length a nominal. anyway let me know what you find!

  173. Kasper Berkowicz February 16th, 2018 5:50 am

    Thanks for your thoughts. I’m considering the adjustable plates as well, might go for that in the long run.
    @rudi: I just tried weighting the ski and that definitely helps some. However, the gap is still too big and I’m thinking the ski will be both weighted and unweighted as I ski it?
    The good news is that I just tried different pair of (new) boots, with the same boot sole length – 306 mm – and those seem to fit well in the bindings. My old boots are really worn. There is definitely a difference in the width of the gap when inserting the left and right boot in the binding. I didn’t think that it could happen, but can the boots have changed length?

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 WildSnow.com 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