Dynafit OEM Speed Radical Anti Twist — Elegant Solution

Post by WildSnow.com blogger | July 23, 2014      
Dynafit Anti-Twist Device, installed to left, shown apart to right.

Dynafit Anti-Twist Device, installed to left, shown apart to right. Click all images to enlarge.

We start covering anti-twist solutions for tech binding heels, and look what ends up on the front porch: Dynafit’s “original equipment manufacturer” (OEM) solution to the less than perfect anti-rotation of their Speed Radical binding heel. (In case you live in a bergschrund: Tech binding heels are usually designed with rotation to effect sideways safety release. This sometimes results in the heel unit rotating accidentally while in touring mode. Various solutions are directed at this problem, the best being hardware ‘stops’ that 100% block rotation.)

This add-on is part# 48870 Speed Radical Anti-Twist Device. Ostensibly available from customer service or through dealers. It looks simple, but is a little tricky to install properly. You have to use the included slightly longer screws, and be sure to flatten any “volcanoes” on your screw holes as the including washers need to sit perfectly flat on your ski. Clean everything well so no small bits of glue or dirt shim up the washers accidentally. Carefully epoxy and tighten screws that are going in for the second time as stripping screw threads in this situation is all too easy.

What you get: Device, washers, slightly longer screws.

What you get: Device, washers (spacers), slightly longer screws.

Anti-Twist installed, with binding in touring position showing how it's physically blocked from further counter-clockwise rotation.

Anti-Twist installed, with binding in touring position showing how it’s physically blocked from further counter-clockwise rotation. Incidentally, that add-on cap attached to the heel lifter is a B&D Nubbin lift extender. I use those because I shim up my binding toes for less ramp, and thus end up with less heel lift.

Looking underneath, Anti-Twist fits over the spindle base.

Looking underneath, Anti-Twist fits over the spindle base. We used double-sided tape between the device and the spindle base to take up some space as well as make the install go easier by holding things together.

Another view.

Another view.

The work went smoothly, everything is nicely thought out.

The work went smoothly, everything is nicely thought out.

Mockup of how things end up sitting on ski. The washers act as spacers to compensate for the new layer of metal under the spindle base.

Mockup of how things end up sitting on ski. The washers act as spacers to compensate for the new layer of metal under the spindle base.

IMPORTANT! Screw hole volcanoes must be shaved to perfectly match flat top surface of ski. Epoxy the new screws and tighten carefully so as not to strip the screw holes.

IMPORTANT! Screw hole volcanoes must be shaved to perfectly match flat top surface of ski, otherwise the washers get shimmed up too high and your installation will have slop. Epoxy the new screws and tighten carefully to not strip the screw holes. And as the Dynafit instructions emphasize, use the new screws!

I found that placing double sided tape between spindle base and the Anti-Twist makes the install easier, and takes up some space that was creating a small amount of play.

I found that placing double sided tape between spindle base and the Anti-Twist makes the install easier, and takes up some space that was creating a small amount of play. Use thin tape, not thick carpet tape, as the thickness of the washers/spacers closely matches that of the Anti-Rotation plate that sits under the binding spindle base.

As viewed from above, the small plastic stopper appears functional and nicely designed.

As viewed from above, the small plastic stopper appears functional and nicely designed.

Just to be clear, another expository view.

Just to be clear, another expository view.

Dynafit Anti-Twist is Art: 48870.

Dynafit Anti-Twist is Art: 48870.

Weight of one Speed Radical Anti-Twist Device (including slightly more weight from longer screws): 16 grams.

Added height of heel unit above ski (thickness of washers/spacers): 1.0 millimeter

Could this device be built into the binding base? Yes, doing so would be beautiful. Let’s lay some odds on who will do it first, Dynafit or the after-market?

Check out the Maruelli Antitwist for Speed Radical, it works on the same concept but has interesting differences.


43 Responses to “Dynafit OEM Speed Radical Anti Twist — Elegant Solution”

  1. Billy Balz July 23rd, 2014 10:32 am

    Any chance you could elaborate on why the heel piece only tends to rotate one way on a blow-out…and also what usually causes it? It hasn’t happened to me, but I don’t generally skin super steep slopes.

  2. Lou Dawson 2 July 23rd, 2014 10:45 am

    It’s due to the angle of the heel lifter in relation to the boot sole, as well as how the heel springs interact with the lobes on the heel spindle, and also how snow and ice build up. I suppose it could rotate the other direction accidentally but have never heard of it or experienced it. The bumer about it is that it often rotates to the alpine downhill position, you don’t realize it, step down, and your heel is locked !#$%^&!!

    It’s not caused by steep slopes, but does tend to happen more on traverses when you’re working multiple angles (sidehill and up).


  3. Dave Field July 23rd, 2014 1:17 pm

    I sure hope you confirm that the currently available Speed turn has three flats on its spindle, similar in operation to the classic TLT. While I have had the occasional unwanted rotation, the basic TLT system has worked just fine for me for over 10 years as a dedicated touring rig. I’ve watched the development of Dynafit’s tech touring oriented bindings with “improved” molded heel piece tower on the vertical models that can break, flip up heel elevators that cause unwanted rotation and feel that while they offer some advantages, notably the option for brakes, they depart from the simple functionality and durability of the basic TLT heelpiece. The new toepieces with stiffer arms and the toe pin locator seem to be a nice robust improvement.

    It seems like what is really missing from Dynafits lineup is a non-auto rotating heel lifting system that is robust, has functioning brakes that can be removed if needed, a less severe ramp angle and the ability to exit the heel pins without detaching the toe-piece all in a durable lightweight package that can hold up to use for several seasons.

    Thanks for keeping us up to date with all things Dynafit/tech binding !

  4. Lou Dawson 2 July 23rd, 2014 1:47 pm

    Dave, after looking in catalog I don’t think the Speed Turn has the extra flats on the spindle, but it might. Will know eventually. Lou

  5. Ted July 23rd, 2014 2:53 pm

    I love that you are throwing extra holes in your new Vapor Nanos for this blog and the other one!

  6. Lou Dawson 2 July 23rd, 2014 3:08 pm

    Sorry to harsh on your love, but those holes were already in there (grin), I was experimenting with mount positions. Believe me, if I’d needed to drill more holes I would have done it on a junker, plenty of those around. I liked the white color of the Nanos for background to photographs the parts and pieces. Lou

  7. Chris Cawley July 23rd, 2014 10:28 pm

    how are the skis…

  8. Kim July 23rd, 2014 10:31 pm

    This might seem like a silly question, but I will ask it anyway. My Speed Radicals came with this anti-twist device installed. They also had the little swing tag advising to only rotate the binding in a clockwise direction. If you obey the swing-tag instruction then to move the binding from ski to skin mode you must rotate the binding clockwise 90 degrees over the plastic anti-twist device – which requires a significant effort. This seems wrong. If I compare to the Maruelli device, that metal pin would completely prevent twisting clockwise from ski to skin mode. So my question is … is it OK to twist the binding anti-clockwise through 270 degrees when going from ski to skin mode?

  9. jerimy July 24th, 2014 8:23 am

    @Dave The Speed Turn is identical in operation to the Classic; flat on ski and two elevator positions. I ordered from Europe last year and used them this past season.

  10. Lou Dawson 2 July 24th, 2014 9:10 am

    Kim, you can twist the heel unit of Speed Radical (or for that matter, any current Radical bindings) either way without internal damage, do it in such a way as seems the most gentle and logical, preferably without forcing it over the Anti-Twist Device. Lou

  11. Lou Dawson 2 July 24th, 2014 9:14 am

    Chris, the Nano review is here, I got the URL by using our site search function (hint hint).


  12. kevin July 24th, 2014 6:24 pm

    The speed radical, originally, did come out in a version with a brass pin that would only allow rotation in one direction. If you happen to have this model you should disassemble to remove the pin before doing this current mod. The newer radical version has the plastic teeth that are suppose to keep the heel from rotating. This version can be rotated either direction.

  13. Stefano Maruelli August 3rd, 2014 11:27 pm

    Kevin you wrote: “This version can be rotated either direction.” ????
    But if you do this you will damage soon your bindings.
    Start with filling the plastic parts, ending with too much play on the main plastic housing (or cracks), and no more antitwist (minimum)…
    An “antitwist” (I invent this word) is made to prevent rotation in one direction, if it can be rotated in two it doesen’t work, or it will go soon out of work.

  14. Dan August 11th, 2014 9:33 am

    @Stefano: Thanks for your thoughts on twisting “against” the plastic teeth. I also noticed it was easy to twist in both directions, but hesitated to do so because I thought the teeth might wear. I don’t have brakes on my Speed heels. Consequently, it is easy to twist the heel in the proper direction. For readers who are having problems twisting the Radical heels CW, it helps to plant the ski that is opposite your “strong” hand uphill. I am right-handed and can easily twist the right heel. I have arthritis in my hands/fingers and cannot readily twist either heel with my left hand. I can easily twist the heel on the left ski with my right hand if I plant the left ski a little bit uphill. Note that the heel twisting issue is more of a problem with my Radical ST bindings than with the Speed heels(no brakes). FWIW, I have been experimenting skiing w/o brakes this past season. That includes about 55 days of general back-country skiing, as well as ski mountaineering…in all kinds of conditions. Of course, I am using a simple leash set-up. Check out this blog for leash set-ups (Thanks Lou). I have been surprised at how well the “leash” works and am abandoning Dynafit brakes altogether. I have never been impressed with their performance anyway and relied on them primarily for stepping into the bindings , esp. with icy conditions, etc. BTW: This past season a ski partner took a tumble and lost a ski (a very expensive yellow one) even though the ski had brakes (Dynafit Radicals). We spent an hour hunting for that ski, which ended up about 100 feet below us in the POW. I suppose that leashes have associated risks too, but my experience this past season tells me it is worth it. Also, w/o brakes on the older Dynafit bindings, I experienced almost no “auto-rotation”, even though I frequently chopped ice off the heel. That said, I still am sold on Dynafit bindings and am not implying dissatisfaction.

  15. stefano August 12th, 2014 12:35 am

    I like Dynafit bindings too: we use in all our test skis and on the Natural Walking Plate… but all with our antitwist base.

    To find Maruelli antitwist you can contact: skimo.co Salt Lake City

  16. Lou Dawson 2 August 12th, 2014 9:06 am
  17. jbo September 19th, 2014 12:21 am

    Hey Lou, thought I’d add that the 2014/15 Speed Rads are shipping with this device. No washers are necessary as the plastic feet have been thickened by 1mm. The longer screws (silver vs black) are pre-installed.

  18. Lou Dawson 2 September 19th, 2014 8:42 am


  19. Charly October 29th, 2014 5:28 am

    … but after installing the “OEM-Anti-Twist-Part” it is not possible to turn the heel clockwise. You are forced to turn it counter-clockwise! I don´t check it 🙁

  20. RockShock November 3rd, 2014 5:32 am

    Does anoyone have a part number of this anti twists? I can’t seem to find them on the Dynafit website….

  21. Lou Dawson 2 November 3rd, 2014 6:31 am

    Hi Rock, the package says Art: 48870. I added photo of package to bottom of blog post. Hope that helps. Lou

  22. RockShock November 3rd, 2014 8:29 am

    Thanks a lot Lou, will see what the local dealer says… 🙂

  23. Lou Dawson 2 November 3rd, 2014 9:10 am

    Good test of the dealer, but you can probably get them from customer service at Dynafit NA if the dealer doesn’t work out:


  24. David November 3rd, 2014 9:56 am

    Can’t help but think the speed superlite is a better design anyway, avoids this rotation issue affecting radical heels and weighs a lot less albeit more expensive.

    The speed superlite c-one available in Europe is possibly even better for general touring applications given the radical toe and adjustable length on the heel unit. Weighs less that speed radical, costs only marginally more and has better heel piece. Not for those who like high heel lifters though i guess.

  25. Ryan November 5th, 2014 6:41 pm

    I managed to get my auto-twisting heel twisting on video, see


    fast forward to about 38 seconds, the heel rotates shortly after that.

  26. Lou Dawson 2 November 5th, 2014 7:00 pm

    Nice documentation Ryan, thanks for sharing! The slowed down cussing when your heel gets locked is like playing a Beatles record backwards for the secret code. Lou

  27. Stefano November 5th, 2014 11:59 pm

    Thanks Ryan, this sit is well known from long time and can be very dangerous in case we are on an iced slope and we can’t stop to remove the ski, to re-set the rear binding in climbing position and re-lock the toe….)

    Approx 10.000 peoples are in the same sit…

    You (all) have now to just to put the right antitwist on.


    Ryan 1 pair free to you if you contact me ( robotec (at) netsurf.it ) , and you’ll make another such good video with my antitwist on.

    Stefano (the unpaid inventor)

  28. rob November 14th, 2014 9:57 am

    so just to clarify…i have the new 2014/2015 speed radicals and mounted them with the “antitwist” To change the binding from ski to walk mode it is only possible to turn the binding counter-clockwise (which is the opposite direction of the turn graphic on the binding). Am i missing something here or is that correct?

  29. Lou Dawson 2 November 14th, 2014 10:38 am

    Correct, if you try to turn the other way the anti-twist prevents, right? I have mine here with the anti-twist, can look at them if you like but that sounds right… Lou

  30. Greg Louie November 14th, 2014 10:59 am

    @rob: It is POSSIBLE to turn the heel clockwiser over the anti-twist device, but requires a lot of effort and IMO is bound to break something sooner or later. There is nothing on the 2014-15 version other than the arrow on the top plate of the heel to prevent you from turning the heel counterclockwise.

  31. Charly November 14th, 2014 11:20 am

    After installing the OEM Anti-Twist-Solution, there is no posibility to turn the heel clockwise. When go uphill youe have to turm counter-clockwise, when you drive downhill, you have to turn the hill clockwise. I´ve the new 14/15 Radical and the Ant-Twist is already installed in common with higher Feeds of the heel for enaugh space.

    It is a horrible mistake of Dynafit, first to go on the market with a problematic binding, and second to let the red graphic “turn only clockwise” on the heel together with the Anti-Twist-Solution!

  32. rob November 14th, 2014 11:35 am

    Thanks guys. I just didn’t want to be doing harm to the binding by rotating counter-clockwise for transition into uphill mode. To return to downhill mode it is a clockwise turn. It is nearly impossible to rotate clockwise over the “anti-twist”, i mean it’ll go with a whole lot of force, but it seems that may do the binding more harm than ignoring the clockwise only graphic. thanks for clearing that up. it seems dynafit should simply remove the turn only graphic.

  33. Greg Louie November 14th, 2014 4:30 pm

    In addition to losing the red arrow, I’d like to see them abandon the plastic top plate altogether and go with a cast alloy one like the Radical 2.0 . . .

  34. Mark Worley December 1st, 2014 9:51 pm

    First day on this binding I noticed many improved features: towers in toepiece, flip up heel lifters. The heel lifters were especially functional. Ramp angle with Radical toe plates seemed fine.

  35. JB December 2nd, 2014 4:40 pm

    So we are all clear…the heel piece can turn in either direction with no short or long term damage to internal parts, correct?
    I hope so because I can’t rotate my heel clockwise into walk mode!….

  36. Lou Dawson 2 December 2nd, 2014 5:24 pm

    Yes, it can turn either direction however in my opinion you don’t want to be forcing it over the anti-rotation tab. It’s very intuitive. Rotate however you want just don’t force it. Lou

  37. Steve Sheriff February 17th, 2015 8:39 pm

    I have TLT Speed Radicals with the “clockwise only” tag and clockwise arrow on them. Like above, rotating them clockwise only, over the stops, is hard. So I emailed Dynafit and here’s their reply.

    From Dynafit: “The anti rotation device allows them to be rotated counter clockwise which is easier and the advisable alternative to extreme force. Please reach out if you have any other questions.”

    They did not comment on why there is a clockwise only tag and clearly recommend rotating them counterclockwise.

  38. Stefano February 17th, 2015 11:11 pm

    All that was just to try to “skip” my Antitwist Patent:

    Use this to avoid any problems (inthernal shaft brakeing to…)


  39. Mike March 23rd, 2016 2:56 pm

    I just had Teton Mountaineering mount my new tlt speed radicals on some new dynafit denalis. I hate the anti-twist because now i have to rotate the heel 3/4 turn every time instead of just 1/4 turn and worst of all i have to bend way over to get to the heel piece. I de-skin without taking my skis off and this is a pain. Instead of unscrewing the heel to remove the anti-twist i’m thinking i could just hacksaw off the black stopper. wouldn’t that work without having to unscrew the heel?

  40. Lou Dawson 2 March 23rd, 2016 3:41 pm

    Mike, yes, you actually need the base part of the “black stopper” as the binding has a space for it underneath and if you remove you’ll get all kinds of play and wriggle. On the other hand, if you remove the anti-twist what’s going to keep the binding from twisting? It’s not made the same as older TLTs and Verts that had a strong stop built inside… ?? Lou

  41. Mike March 23rd, 2016 4:44 pm

    Thanks for your reply Lou. I got ansi before i received your email and hacksawed of the top of the little black stops. I’ll ski tomorrow (probably in some slop) and let you know if the heels come around on me.

  42. Lou Dawson 2 March 23rd, 2016 4:54 pm

    I’ve tried them without anti-rotation, didn’t work for me, but they “almost” did… FYI

    Please do report back.


  43. stefano March 24th, 2016 12:18 am

    This is what will again happen without the antitwist:


    To solve this problem I produce this:


    You can find in US&Canada at: http://www.skimo.co

    Thanks to Lou for the review.

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