(This post sponsored by our publishing partner Cripple Creek Backcountry.)
Building on the venerable Radical series, Radical 2.0 offers a completely reworked heel unit that in our opinion is nearly impossible to blow up, as well as a rotating toe that’s said to make the binding less prone to pre-release. Testing last winter proved that “Rad2”, while fiddly in some ways due to the rotating toe (and not tourable unlocked), is a durable and effective ski touring binding.
Enter the Dynafit Rotation ski touring binding. An upgrade overall similar to Rad2; heel unit identical, important changes in toe unit.
Rotation has an improved toe unit that’s easier to use; it’s otherwise virtually the same binding. In all, a solid addition to the large variety of “free touring” tech bindings that boast integrated brakes, heel units that adjust to ski flex via a spring loaded track, and overall beef.
Below, I do a bit of comparo as to the differences between Rad2 and Rotation, and segue into describing how both bindings deliver their promise of a strong ride. Please know this is not a review, that’ll come later this winter after we abuse the retail version Rotation.
And the numbers…
Radical ST 2.0, heel unit, 110 mm brake, 416 gr – 14.7 oz
Radical ST 2.0, toe unit, 230 gr – 8.1 oz (steel wings)
Radical ST 2.0 single binding, total, 646 gr – 23 ounces
ST Rotation 10, heel unit, 110 mm brake, 416 gr – 14.7 oz
ST Rotation 10, toe unit, 208 gr – 7.3 oz (aluminum wings trim 22 grams, nice to see “negative weight creep”)
ST Rotation 10 single binding, total, 624 grams – 22 ounces
Delta and stack height are identical. See this post for numbers.
With both bindings, the question: Why the rotating toe? According to Dynafit, this mechanical system allows the boot to absorb shock (essentially, a partial release) without the binding toe pins riding part way out of the boot toe sockets. In the case of tech bindings without rotating toe, every time the boot moves in lateral or rolling shock absorption, the toe pins ride some distance out of the boot toe sockets. Idea is that once the pins are partially out, the system is more prone to accidental release. Pop. Makes sense and can be easily simulated on the bench by moving the boot heel partially through the lateral release cycle and evaluating how much force it takes to knock the boot toe out of the binding toe — comparatively done in the case of both rotating and non-rotating toes.
The burning questions are, of course, is the rotating toe unit truly beneficial in real life use, and are there any tradeoffs other than the added weight? (Engineers will tell you, any time you change part of a machine there are _always_ consequences).
My “rotational” take: I’ve always felt that a unique feature of most tech bindings was that the boot toe fittings “ball and socket” joint provided a modicum of spring loaded resistance and shock absorption. In the case of a rotating toe, this front spring action in partially eliminated as the toe rotates (the springs only engage during the latter part of the release cycle, when the boot finally pops out of the toe unit). My take, could be a wash; could be an improvement.
Anecdotal accounts from binding testers indicate both Radical 2.0 and Rotation clearly have no more problems with accidental release than the original Radicals, perhaps less. Getting a firm read on that is tough without some sort of organized field study, and I’ve not heard any plans for the NTSB to be doing crash dummy testing with ski bindings (they’re busy figuring out how to test self driving cars). Mainly, I’ve spoken with strong and aggressive skiers who are very happy with the binding. So fine. Let’s leave the great rotation debate to the comments, or to the future after more consumer testing and WildSnow bench racing.
(If you chime in with glowing accolades for your Rad2 or Rotation in terms of release-retention performance, we’d be delighted to hear it. But please share what release values you’re skiing the binding with, as pegging the settings and thus essentially eliminating any sort of practical binding release probably makes any performance contribution from the rotating toe a non issue.)
Sidebar. I should mention that an ongoing problem with tech binding ski setups is boot toe fittings that don’t smoothly release from the toe pins, due to manufacturing defects or wear and tear. I’ve been told by insiders that getting the boot-binding tech interface right takes it to the limits of metallurgy and manufacturing. The rotating toe mitigates this challenge. Once the boot is partially through a lateral release cycle as allowed by the rotating toe, the system would have to be highly compromised for a release not to occur. Considering that, even with the rotating toes, all boot-binding combinations should be bench tested for releasability before being skied.
Conclusion: Both bindings are virtually the same. While clearly a good idea in terms of shock absorption performance, the toe rotation can be problematic. You can’t tour with either model’s toe unlocked, and clipping your toe in can be tedious. Rotation model significantly mitigates the tedium due to the toe rotation detent — this is the only major difference between the two grabbers. Nice the alu wing arms of the Rotation save 22 grams per binding. We like the rotation’s slightly taller toe “trigger,” this will go unnoticed by most people but saves tuning work for the outliers with boots that don’t interface quite right. As mentioned above, while this is not a review, I’m comfortable giving Rotation a 98% of two thumbs up base on this bench race. We’ll see if the last 2 points can be added after we test the retail version binding this winter.