Maruelli AntiTwist for Dynafit Radical Series Bindings

Post by blogger | March 2, 2012      
Radical series binding with Antitwist aftermarket solution.

Radical series binding with Antitwist aftermarket solution. Simply a mechanical stop that the binding rotates against. Idea being the amount of plastic riding against the stop (indicated by red arrow) is vastly stronger than what's asked to work with the stock internal 'pin.' Nonetheless, we've not tested this solution for wear and tear, so be advised it still needs consumer vetting. We'll field test during coming weeks.

Ok, known Dynafit Radical binding issue: Inside heel housing a small pin is intended to prevent the binding from rotating counter-clockwise past a certain point. The idea is that while you’re in uphill mode, you don’t want the binding heel accidentally rotating 90 degrees counter clockwise from the normal position, as this snaps you into a locked heel — annoying to say the least.

Problem is…

The original version of the stop pin was strong enough to overcome the strength of the binding plastic, thus possibly damaging the heel housing. An upgrade from Dynafit provides a pin that’s intended to sheer before blowing out the binding. In some views this is a stop-gap solution.

Enter Stefano Maruelli, who’s made a simple add-on plate that provides a binding rotation stop. The plate can be seen in the video below, and some still shots. I’ll test this solution for a few weeks and publish our take after that, but other than the weight penalty, this looks like a smart solution (I have two test versions, one of thinner steel weighs 24 grams per binding, while a thicker version weighs 29 grams.)

Anti-twist is installed under the brake retractor plate. Elegant.

Anti-twist is installed under the brake retractor plate. Elegant.

Stefano doesn’t have any US dealers at the moment, so to obtain the Anti-twist you’ll need to get it directly from him. Contact via his website. More information here.

Cost is 20 Euros for the 1.5mm (lighter) version, 24 euros for the 2mm. Shipping cost to US-CANADA around 20 Euro via registered letter. Payment can be done via Bank transfer or PayPal.

As I’ve mentioned before, some folks can simply remove the pin from the Radical heel unit and be happy. Others may like the Dynafit solution. If either of those are not satisfactory, consider the Maruelli Antitwist.


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41 Responses to “Maruelli AntiTwist for Dynafit Radical Series Bindings”

  1. John Gloor March 2nd, 2012 9:50 am

    Lou, any reason why Dynafit changed the multi position post for the current climb or ski options? It seems like spring tension worked pretty well for decades to keep the heels from rotation. I have the new Radicals, and have not upgraded to the new shear pin and am some what disappointed that the new binding can crack its plastic or has to rely on a small pin.

    I don’t have parts to do this, but would the new radical heel work on older FT/ST posts?

  2. Lou March 2nd, 2012 10:09 am

    John, they changed it at least in part because the older design did indeed “auto rotate” for some folks. I’ve had it happen myself, numerous times. The heel unit is still held in position by spring tension just like the older, only with the added benefit that one direction of rotation is totally eliminated, and the other direction isn’t as high consequence (it doesn’t end up with you stepping down an accidentally latching into alpine mode.) Also, yes, the binding heel actually functions like the old version if you remove the pin. Not sure if the parts swap from one to the other. Some of the internals are quite different. Lou

  3. Maciej March 2nd, 2012 11:28 am

    Radicals seem like they’re a step forward in a lot of ways. Too bad Dynafit didn’t beta test them thoroughly enough to work out this kink. While this isn’t a massive problem (aka Salomon tech fittings) it’s still always a little unnerving when a backcountry product gets released and it turns out there’s a design flaw. Hopefully (probably, considering Dynafit’s track record righting design wrongs) it’ll be rectified within the next year or two. Until then, I’ll just keep skiing my Vertical FT12’s, which have been trouble free for me.

  4. Mark Sweatman March 2nd, 2012 12:08 pm

    I seem to have missed something here… I thought the whole point of the radical (I’ve never actually seen on in the flesh) was that it only rotated 90 degrees? Why is it being rotated what looks like 270?

  5. Lou March 2nd, 2012 12:18 pm

    That’s how you get it to downhill mode… without the pin or the Antitwist you could rotate it the other direction and yes get there sooner. That’s one of the issues with the Radical, the fact that unlike the Vertical ST/FT you can’t as easily get it rotated to downhill mode — but again, that’s by intent due to concerns about auto rotation. Or at least that’s all my understanding

  6. Charlie March 2nd, 2012 1:26 pm

    Any word on whether Dynafit plans to completely bury the Classic/Speed? It’s a great binding, and it appears to have disappeared from the US market in order to prop up the price of newer options. A $200-$250 Speed, optionally with 5mm more adjustment range, is all I think I want in a binding…

    I’ve been helping a bunch of people with new setups this year, and what they’re looking for isn’t newer/better bindings, it’s reliable bindings that they can afford.

  7. Tim March 2nd, 2012 3:39 pm

    Charlie, I’m skiing the speed radical, check that out. Even the tlt speed clocks in at $340, so not sure how you’re planning on getting them for $200

  8. Marc Williams March 2nd, 2012 5:52 pm

    Lou: I have used my new Radical TLTs twice and now have the auto-rotation problem. I could get a replacement binding from the dealer I bought it from but there may still be the same issue? How common is this defect?

    You show what looks like a good solution, the Maruelli plate. Does add a tiny bit of weight. What is the Dynafit solution you discussed in your blog? Taking out the old sheared pin is an option but won’t the binding still auto-rotate? Thanks for the help..

  9. Daniel March 2nd, 2012 8:01 pm

    As much of a Dynafit slut as I am, I hate to say the unwanted rotate and locked heel situation has happened to me. It’s really a minor inconvenience, but still sucks. This looks cool.

  10. John S March 2nd, 2012 8:23 pm

    Hey, I want something like this for the STs. So that I can rotate the heel to touring mode, rotate to the two lift positions, but not allow it to go back to skiing mode unless twisted around.

  11. F. Felix March 3rd, 2012 9:07 am

    Too bad Dynafit over-reacted. The auto-rotate problem was an issue with the ski brakes not being pushed down far enough when rotating the heel. That shears off the plastic thimble, allowing auto-rotate to happen all the time. Dynafit should have redesigned the brakes: get rid of the crappy brakes, get rid of the problem.

    At least with the pitch-perfect Speed, you can quickly and easily get out of locked mode without releasing the toe. Doesn’t seem to be the case with the Radical. Not an improvement at all in my book.

  12. Mike McL March 3rd, 2012 8:37 pm

    Looks like a great idea. I’ll be ordering a set. Recently, I had a radical heel piece rotate in the wrong direction inadvertently while skinning. Even with the new pin, the plastic housing cracked. Dynafit is replacing the heel, but that doesn’t solve the problem. I’m wary of having the same thing happen when I’m far from the trail. This looks like an elegant solution. I like this idea better than removing the pin itself. I can handle the minimal weight penalty.

  13. Mark W March 3rd, 2012 11:50 pm

    One possible concern is if the Maruelli anti-twist part were to somehow be impacted, deforming the piece. This could perhaps interfere with the heel rotation. Perhaps this is highly unlikely, but still possible.

  14. Lou March 4th, 2012 1:05 am

    Mike, with this solution you would still want to remove the pin. The whole idea is to remove it from the scene.

  15. Mike McL March 4th, 2012 1:21 pm

    OK, thanks Lou.

  16. Jesse March 6th, 2012 7:30 am

    That’s a clever design, moving with the brake plate like that. My pet ‘what dynafit should have done’ theory is that they should have had the pins point straight back in touring mode – then a 90 degree rotation wouldn’t snap your heel in. Yes, this would have caused several other design issues, but it’s fun to think about these things.

    Lou, F.’s comment reminds me that it’s supposed to be possible to release the heel without the toe on all models without a brake, isn’t it? Does that also work on, for example, the Radical ST with the brake removed? How do you do that? Why does the brake prevent it?

  17. Lou March 6th, 2012 9:07 am

    Jesse, the brake doesn’t “prevent” it, the problem is it pops up and then you can’t rotate the heel unit the rest of the way to touring position. Sometimes you can overcome that with a very tricky series of motions, but doing it without the brakes is the best way. Fiddle around on the carpet, you’ll figure it all out. Not sure how you’d do it with Radical, but there is probably a way. Anyone messing around with this? Lou

  18. ptor March 6th, 2012 10:41 am

    Solution = Plum

  19. Dave Carver March 6th, 2012 12:29 pm

    Does the Maruelli solution work for those of us who don’t have brakes?

    Has anyone had propblems with the new binding’s heel lifts? They are easy to use but seem to be fragile.

  20. Lou March 9th, 2012 9:43 pm

    I just met with Dynafit top dogs and engineers today in Munich. Among other informations I’ll share in a coming blog post, they have an anti-rotation solution that’s similar to Maruelli’s, only much much smaller and made of plastic. Really quite nice though it needs to be tested of course. The word is that all dealers will have it available. Lou

  21. David March 10th, 2012 1:30 pm


    Any word about Dynafit solutions for Radical Speed (ie sans brakes)?…I’ve now broken 4 “new” pins and it is getting rather tiresome. The Maruelli Speed Radical solution involves a new back plate and is big $$.

  22. Lou March 10th, 2012 1:52 pm

    David, does it work for you to simply run without the pins?

    Frankly speaking, also, why not just go back to the old style Speed TLT? About 20 zillion skiers seem to be quite happy with it… in Europe, you constantly see ones that have obviously been in use 15+ years. Amazing. The inventor should be canonized.

  23. David March 10th, 2012 2:07 pm


    Now I’m running without pins, but specific snow/climbing conditions will repeatedly pop them into ski mode. There was mention of screwing in an anti-rotation screw/bushing into the ski to the left of the base. But with the forces, I don’t want it to shear off/rip out the screw. Any thoughts on the force issue?

    I do have access to a 3-D plastic printer that can fabricate parts with the strength of high impact plastic in certain planes (depending on design). So I was thinking of printing up some L brackets with two screws to act as a stop…but again forces?

    Yeah, this year I tried to get the old style speed TLTs but I couldn’t find them locally…something about dynafit trying to phase them out…so went with Radicals. Maybe I can find two heel units of these….any ideas where?

  24. Lou March 10th, 2012 2:36 pm

    David, I think screwing something into the ski would work just fine. I’d use a fairly large screw and something with a wide base, along with plenty of epoxy. From my own experience, the “auto rotation” forces are not all that great. Have to say that this is a bummer, as the Speed without brake doesn’t allow the easy external anti-rotation options. Lou

  25. stefano March 29th, 2012 11:42 pm

    Hi friends a nice news:

    My Radical Antitwist can be installed onto the old FT Bindings !

    We cannot check, but we are quite sure that also the Click-Clack can be installed on.

    So wth those 2 upgrade you can hold a fully new “Radicalized”, but fully safe and working, bindings.

    Shipping world wide via Post or Currier. Paypal payment.


  26. stefano March 30th, 2012 12:06 am

    Hi David, for 49 Eurso shipping included you can hold a perfect “final” solution.. 1.5 or 2mm Inox made… since forces in kick turns are soo high: from 1g so weight of the skiers, to more than 9g of peak…

    So first is: learn to do “italian” turn: no kick easy also in deep powder or very very steep conditions….

    Second is: buy a Maruelli Antitwist plate !


  27. travis July 29th, 2012 8:58 am

    Has anyone in N America successfully ordered from Stefano? I placed a combined order with someone else (to share shipping costs) way back in March. We still haven’t received anything, and he has not been responding to emails.

    At this point I think I’m giving up on Stefano, and I’ll just use the free version that Salewa is sending out to folks.

  28. Stefano July 29th, 2012 9:57 am

    Hi Travis,

    I’m still here ! And I’ve not received any new mail from you after my shipping in march !

    I will check for your shipping and I let you know.

    Pls you can use this e.mail for question/answers or the one you’ll find at

    I hope you’ll receive also my e-mail on that.


  29. Mike McL August 29th, 2012 9:40 pm

    I went in on shipping w Travis on the order above. After a shipping SNAFU the plates arrived today. Once the snow starts flying we’ll see how they work

  30. Juergen October 15th, 2012 9:36 am

    Hi guys,

    Hope you had a nice summer !
    As first snow showed up in austrian mountains I’ve started to plan for a new quiver – again, as I postponed it last winter due to the tech issues with the Radical ST.
    Big question remaining for me: assuming all braking/rotation issues have been more or less resolved during summer, whats your experience the new flip over heel lifter mechanism ? Is it superior to the vertical one ? Price difference is 60€ only and I’ll keep the new quiver for min 3 years. I do night skitouring twice a week, so please also consider the lifters handling also in bad sight conditions !

    Thanks to all !

  31. Dan October 15th, 2012 9:43 am

    Juergen, I like the action of the Radical heel lifters better than the volcanoes. They are, however, difficult to see when the light is poor (my eyesight is not the best either). I plan to coat the levers with some bright paint or some sort of “reflecting” paint.

  32. Jody December 11th, 2012 11:40 pm

    My radicals totally blew up today. The whole heel riser assembly of one just ripped off and got lost in the snow somewhere. On the other heel piece, the assembly is starting to pull the bolts right out of the heel piece. This is because of the mechanical advantage of my body weight pressing down on the riser and levering through the shaft that the risers are mounted on. This pulls up on the plastic plate which is held down by 4 little torx headed bolts. What a crummy design. I understand some people like it (probably people who don’t ski much and/or don’t weigh much and/or don’t use thier risers and/or don’t do much back country), but WHY can’t we have the option of just getting the old TLT speeds??? Why are they jamming this terrible radical design down our throats? Mine blew up after about 40-50 back country days (0 front country days), and 1 year 17 days after I bought them. My old TLT speeds went for 5 years and are still going strong.

  33. stefano December 12th, 2012 10:45 am

    Hi Jody,

    The new Radical seems stronger… but

    If you like the TLT and the original “Click-Clack” system take a look here:

    Is still availabe with new stronger pins.

    Just note that if you’re heavy skiers do not use the 3th level, and little care for installation (do not over-turn the screws in the plastic housing…)


  34. Jody December 12th, 2012 1:12 pm

    What?!?!??! Don’t USE the 3rd level?! What?! No. That is unacceptable. Because with the old binding, I used the 3rd level for YEARS, with no issue. If the new design can’t be used by “heavier” skiers with the risers in the 3rd position, then the design is faulty. And, like I said, all a lot of us want is to be able to get the old design. I don’t care who wants to use the new design, knock yourselves out.

  35. Tim December 12th, 2012 1:15 pm

    How heavy are you Jody?

    BTW, you can still buy the TLT Speed and the Vertical versions. No-one is forcing you to use the radicals. There are also lots of other options out there(Onyx and Plum)

  36. Rod June 6th, 2013 12:54 am

    First of all, thank you for the great effort of uploading so much useful information on this website, it is very helpful!

    I’m really a newbie on dynafit bindings, I have the radical FT installed on my skis and I have installed Maruelli anti-twist solution as you show here.

    As I look at the radical FT heel piece, my impression is that this piece is intended to be rotated clock-wise only, or am I wrong?
    After the anti twist is installed I won’t be able to rotate it clock-wise only, I will have to go back and forth

    After continuous use, is this counter clockwise rotation going to deteriorate the binding??

    Thanks in advance

  37. stefano June 6th, 2013 1:43 am

    Ciao Rod,

    If you’ve removed the inthernal Pin & Spring, there is no longer what damage your bindings durring rotation or underload.

    Thanks lot,

  38. Uros December 17th, 2013 8:46 pm

    I have TLT Speed Radical bindings and autorotation is a constant problem (happens about 10x on a single tour). I hate Dynafit bindings but I have no money for new bindings. I am thinking of buying these antirotation plates:
    – Has anyone tried them? Would you recommend them?
    – Is the installation problematic? Do I have to drill holes in the skies?


  39. Stefano December 17th, 2013 11:20 pm

    Hi Uros,

    2 solution for you (plus 1 next year):

    1) Since the Antitwist Plate works for Radical WIth Stopper.

    We can send you a New Radical base With Stopper (92mm enought?) + antitwist plate.

    2) We have a special base for the Speed Serie you can see in the link here:

    In this case you’ll need to re-drill and you’ve just 6mm of regulation front-back.

    3) We have a new patented solution, but require to have bindings in the hands and will be ready for selling from next year.

    for info: robotec(at)


  40. stefano March 4th, 2014 12:26 am

    Hi Radical Speed & TLT Holders,

    There is a new solution to upgrade yur bindings to a 73mm slide rental version:

    Same holes of Dynafit STD or Rental Radical.

    hope can interest someone that won’t be locked again by self rotation of Speed and TLT.


  41. Stefano April 5th, 2017 9:16 am

    We check that the Antitwist for the Radical can be used also on the OLD TLT COMFORT, with of course the Click-Clack. For info in the US contact Skimo.Co, for Europe/Asia


    …we are still upgrading the old family !

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