Dynafit Dy.N.A. “Race” Boot — it’s here!

Or rather, my pair is now here.

After Lou first blogged about this new boot, he was supposed to steal me a pair from Dynafit Euro HQ when everyone was distracted. But Lou gets distracted by those pastries, so it didn’t work out as planned.

Fortunately Salewa in Boulder, Colorado was able to locate the only pair in my size available for sale anywhere in the U.S., and Bob at The Elephant’s Perch (“people powered sports specialists”) thus had a pair to sell to me.

Unlike other backcountry skiing gear, I feel compelled to justify buying such a boot. After all, the rando race circuit” in New England is hardly very well developed, and anyone who knows me well knows that I am far (far) from elite levels as a competitive athlete (either in terms of competitive drive or athleticism).

But that brings me to the ironic part about the Dy.N.A.: if Dynafit set out to create the ultimate rando race boot, then Dynafit has failed according to some hard core rando racers, who cite the boot’s excessive weight.

What? Well, my size 26 pair weighs 4 lb 1.2 oz. Now, that is disturbingly light compared to any “normal” boot on the market. (And that’s not much heavier than my Salomon nordic backcountry ski boots or my Asolo “lightweight” fabric & leather hiking boots.) But the 100% carbon fiber boots from Pierre Gignoux and La Sportiva weigh about a pound less per pair. Yet these boots do not appear to be practical for extended backcountry use, especially tromping around off snow in the late spring and early summer. Plus I can’t imagine squirming around a small cold tent in the early morning trying to squeeze into a boot that requires its own instructional video.

However, you can find reports on the web that skiers were acquiring the Dy.N.A. just for . . . skiing. Despite the absurdly low weight, the boot was reported to be stiff enough to drive the Manaslu — yes, that’s right, Dynafit’s second biggest ski (and designed with graphics to match up with Dynafit’s biggest boot at the time, the Zzeus), paired with Dynafit’s lightest boot.

As much as I love my Dynafit Zzero4-C TF boots, I have experimented with lighter boots over the years: the Dynafit MLT, the Dynafit TLT Evo, the Scarpa F3, and the Scarpa F1. But the Zzero4 just skied so well, and was only ever so slightly heavier than the lighter models, that I kept only the F1, and then only in modified form for rando races and ski resort skinning.

So how does the Dy.N.A. ski? Thus far I’ve taken it on six outings: four on my cheapo Atomic race skis (3x on groomers, once in a rando race with nasty ungroomed conditions), and two with the Manaslu — one just a short outing on lower-angle terrain, and one decent day of just under 8,300′ vert (unfortunately cut short b/c of baby duties, highway closure, and Town Planning Board duties).

Laterally, the boot is amazingly stiff. Skiing firm ski resort groomers with my cheapo Atomic race skis, I was able to get my skis out from underneath me and angulate almost as much as on my slalom race setups — I never knew those cheap skis could ski so well! On a rando race’s fairly steep ungroomed trail with all sorts of refrozen nastiness and misshapen moguls, I was able to control my skis (and thereby ski way faster) far better than with any other lightweight boot. In very tight and fairly steep (i.e., steep enough to slide) backcountry terrain, the ability to muscle the Manaslu around when necessary was excellent. (Conditions were 8″ of untracked on top of the older base, including one run that had a 1 cm crust separating the 8″ of new from the old, so on steeper terrain with sharper turns, the Manaslu would break through into the older stiffer snow, and hence needed some torquing about.)

Rearward support is also excellent. The boot has a wee bit of give at first because of the walk-ski mechanism (as with any AT boot, compared to, say, an alpine plug boot with its massive fixed rivets), but then is absolutely solid. That brings me to my biggest criticism. The DyNA is definitely not as stiff in forward flex as the Zzero4. Okay, so that’s not much of a criticism, i.e., Dynafit’s lightest boot ever is softer than what was its heaviest boot only two seasons ago. But I think the contrast between the very stiff forward flex and the far less stiff forward flex can be a bit surprising if you get rocked back. Or at least that seems to be what I was experiencing sometimes.

Otherwise, I’m wondering when I’m next going to use my Zzero4. How could the DyNA be even better for all-around touring? One of my first thoughts when I tried on the boot was that adding a plastic tongue and a velcro strap to the upper cuff would improve the skiing performance to the point where I might retire my much beloved Zzero4 entirely, while adding only around a pound or so per pair. I then read that this is the upcoming TLT5 Performance TF. (Along with dropping the carbon fiber in the TLT5 Mountain TF-X for a more typical price point.)

Note a big caveat that I haven’t been using this at big speeds in open terrain. (And no air, and I weigh only 145 lbs, and I’ve used the boots only with a day pack, without any avy rescue gear.) For that, more forward stiffness is a definitely a plus. Also, at speed just extra mass by itself can be helpful, especially to prevent deflection. The total for the DyNA + Vertical ST + Manaslu = 11 pounds, 13.4 ounces, i.e., not much more than some of the heavier skis alone out there in the backcountry. (And at the other end of the quiver spectrum, my alpine race “plug” boots plus Atomic 1018 bindings and 209cm speed event skis weigh in at 29 pounds, 8.8 ounces.)

Oh, and the range of motion in tour mode is if anything excessive (i.e., probably exceeding my flexibility) and the resistance negligible (i.e., probably even less than my nordic skate boots). Never mind that old skinning efficiency goal of matching up with the ski tip with the binding toe. With my 160cm rando race skis, most of my strides now match up the ski tip with the binding heel. With my 169cm Manaslu, the ski tip typically matches up with the middle of the ski boot.

What else? Well, why does this boot appear to have a DIN-compliant sole? (Using this in a Fritschi or Marker probably activates some alarm in Dynafit HQ to send out the repo squad.) Still though, it walks amazingly well, in part because the boot sole length is so incredibly short: my bare foot measures 265mm, and my ZZero4 shell is 296mm, yet my DyNA shell is only 287mm, i.e., only 22mm of plastic, foam, and wiggle room addded to my foot length. One drawback: the rubber lugs for the toe and heel are separated by bare plastic, so be careful with your off-snow scrambling where you position your foot on a critical hold.)

Also, if you plan to modify the length of the 2.5mm kevlar cord buckle “bails” then do so *before* you use them, since otherwise the square knot becomes very difficult to untie, although you can make new loops from the supplied additional cord. Based on cutting some additional loops, I doubt the cord will accidentally be cut while skiing, but bring along an extra instep loop is a good idea for long tours, as well as some rando 3mm accessory cord for the upper cuff buckle. (The upper cuff buckle cord has to be rethreaded to be replaced, so the larger diameter cord will work fine.) Note that even in case of catastrophic upper buckle failure, a repair kit is very simple: a large screw rivet to lock together the upper cuff parts, and the long Voile strap you’re already carrying for other purposes.

Fit? Generally very slim throughout, widening in the forefoot. Everything about the boot just feels very close to the foot. Oddly enough, I was able to drop in my custom footbeds from the Zzero4, although the boots just feel so different: the Zzero4, like any AT boots is a big foam and plastic contraption with a space inside for my foot, whereas the DyNA feels like an ultra thin addition to my foot allowing it to lock into a Dynafit binding and ski.

Overall, this strikes me as the ultimate ultra lightweight touring boot, with its TLT5 derivatives next year taking their place as the ultimate lightweight touring boots.