Discussing ski touring boots is a dirty addiction of mine, as I have yet to find the holy grail of touring footwear: a progressively-flexed, tight yet comfortable, light yet burly boot that, whether tongue or overlap, delivers enough power to smear & slash DPS Lotus 138s, stomp cornices, and pull off tight turns in adverse conditions including windcrust and sastrugi. That said the boot  must remain nimble and precise when counting on it, with sticky rubber underfoot for sketching across an exposed traverse or kick-stepping up some scary ice. And of course, it must be comfortable in the uptrack, like an old house slipper that delivers support and warmth without being intrusively snug. To this end, and without really spending much time fitting them, this year I picked up the Black Diamond Quadrant, which—I must say—has to be one of the better attempts to design a stiff and strong yet lightweight overlap touring boot.

The Black Diamond Quadrant in spanking green & yellow.

The Down. The Quadrant skis like no other touring boot I’ve had the pleasure of riding, and that includes the Garmont Radium and Scarpa Spirit series. Note I am not comparing it to the Dynafit Titan or the Factor, which weigh much, much more and are made with PU and not PeBax, nor to the Scarpa Maestrale, which, although it marks a serious step forward in tongue-overlap innovation, is nonetheless a significantly softer boot. That said, the Quadrant feels about as stiff as both the heavier Factor and Titan, while being a much lighter and more agile boot.

Apostles in full glory. See the boots? Didn't think so. Skier: tobias c. van Veen. Photo: Matt Hallinan.

Flex. The Quadrant is stiff, and its 120 flex claim is not as exaggerated as other manufacturers. It has a hard forward flex which, if anything, could be more progressive (a few riders report shinbang, and the boot does pressure across the top of the shin when aggressively pressuring forward). But unlike many overlap touring boots, the Quadrant will hold tight at speed; it has yet to collapse forward in unruly, bumpy terrain, unlike a softer touring boot which will throw you over the handlebars when challenging the tips of the skis in an aggressive stance. Lateral flex is also impressively stiff, providing solid support edge-to-edge and for holding down the carving aspects of the turn. Indeed, in many respects lateral (as in torsional) stiffness is the more important aspect of a boot’s flex as it determines how the boot flexes three-dimensionally in the gut of the turn (the same goes for skis).

That's some nifty forward flex in walk mode!

Walk mode. In walk mode, the boot hinges forward impressively well, with a long forward motion for the uptrack. With the top two buckles undone and the power strap released, there is little resistance on the forward stride. The Quadrant’s sliding-hinge innovation appears to do its job, allowing the cuff to move noticeably forward. In this respect it has some of the best forward motion on uptrack tours of any boot in its class (i.e. the Quadrant is not to be compared to a Dynafit DyNA or TLT5—though these models have upped the ante for what will be the future of touring boots). Also worth noting is a fully field-replaceable walk mode lever. Made out of metal, it’s not going to break easily.

Where the boot seems to have lost some movement is with the rearward hinge, which should move much farther back than its tight cuff allows. Unfortunately the boot has a tough time moving back past 80 degrees. Note you can mod this. I removed the rear cuff and ground down (with a Dremel) the spines below the walk mode lever on the rear of the boot and in the corresponding notch in the cuff. This yielded a few more degrees of easier rearward movement, but it is evident that the cuff has been molded a tad too tight. Hopefully Black Diamond will correct its mold in future versions, as the design of the boot should yield increased rearward movement. While less noticeable on the uptrack, rearward stride is a calf-saver on the flats, where efficiently-executed nordic skiing technique can mean the difference between cuddling up in the fartbag while watching the alpenglow… or sketching it out by headlamp through a dark glacier of ugly slots.

Not-so-nifty rear movement. Boo.

Materials. The workmanship of the boot is capable and strong, with a decent lugged sole and burly Dynafit inserts that show little sign of wear after a good number of days out scrambling. The wire buckles have yet to show any disadvantages. The hooked buckle clasps designed for locking-out the buckles in touring mode take some getting used too—they can be very difficult to unhook—but work well enough. Unfortunately the powerstrap is something of a let-down. A larger, rubberized powerstrap would give the boot some progressive flex when combined with a looser buckling system. The current powerstrap is so measly that it can nearly be undone without any notice in the performance of the down, which means it is nearly superfluous in the design.

Like Scarpa, Black Diamond has gone to some detail to reduce weight, utilising ribs in the shell, as well as displaying fine craftsmanship in recessing the rivets.

Shell Fit. This is where most of my concerns lay: surely a decent boot should fit snug, thereby allowing the bootfitter to press and punch where needed? This rule has yet to change in however many eons of boot development: you can work with a tight-fitting boot. You cannot, however, do much for a sloppy, loose-fitting boot.

So be forewarned: the Quadrant is a very roomy boot in length, width and volume for its boot sole length (BSL). A size 27 is only 310BSL, which is frustrating, as industry consensus usually is for a size 27 to come in at around 315BSL. This means if you have a US men’s size 11 foot—by far the greatest demographic of men’s feet—you either have to size down to a 310BSL and punch a good 5mm in the toes, or size up to a 28 and try and pad out the extra 5mm (one finger) of space. I went larger—more on that below as I reconsider the decision.

As for width, a size 27 has a 103mm last. This is quite large even for touring standards, and when combined with the large volume of the forefoot, perhaps too large to achieve a performance fit in a boot that will break in over time. What is especially frustrating, however, is that the boot last changes proportionally to the size. Thus a size 28 has a 105mm last—which is massive!—while a size 26 a 101mm last. For the life of me I don’t understand the logic, as longer feet are not necessarily wider feet (!). In short, if you have a long, narrow, low-volume foot—and if you want this boot—you are going to either have to go small and press & punch, or go big and fill out the space with everything you can think of (and then some).

No bootfitter I have spoken to can figure out Black Diamond’s thinking on this matter. Why not stick with a consistent last, thus allowing bootfitters to only press where necessary? Certainly a 101mm last would have been sufficient. One hopes Black Diamond rethinks the overall shell sizing; I feel that we’re all still waiting for a 101mm last, lower volume boot for those seeking a performance fit that will last much longer than the kind of fit a large, and ultimately sloppy boot will deliver. In short the shell has been sized for the recreational backcountry skier: it feels good to begin with, when really, it shouldn’t.

The tech fitting is well positioned and works well with Dynafit.

Toe buckle. One other common remark concerning shell design is the toe buckle. Why it exists is perhaps a good question given that the Prime eschews it. Moreover the positioning of the buckle on top of the boot serves little purpose save to pressure the overlap hinge directly on top of the toes. Doing up this buckle so that it actually tightens the shell only indents the overlap, which is painful for most rider’s feet. I only moderately do up the buckle, which again makes me wonder if it is even necessary. I have since skied with the buckle completely loose and noticed little difference in performance. Raising the toe with a bondex board produces a better toebox fit than tightening the buckle. For those with a decent toebox fit, removing the buckle entirely might be a useful mod to reduce weight and resolve toebox fitting issues.

Stock liner vs. Intuition Pro Tour

Stock liner. While the stock liner is thermomoldable, it feels quite soft and mushy once molded. Users also report that the liner is too small for the shell, which has also led to incorrect bootfitting (always size the shell, not the liner!). My own liners slipped inside the boot shell; they had shrunk in relation to the shell (again this seems to signal that the shell is too voluminous). It would appear that instead of using foam that expands to fill space in the shell (a la Intuitions), Black Diamond used foam that shrinks around the foot. Having one’s liner slip inside the shell is unacceptable.

I have since tried Intuition Pro Tour liners. While providing a much warmer and closer fit than the BD liners—as well as not slipping inside the shell!—there is still too much overall volume, and I am experimenting with Intuition Luxuries, footbeds, bondex boards and good ol’ 3M sticky foam to try and achieve a tighter, more precise fit. In short I am going down that ugly road of filling-in-space which is the stuff of bad dreams for bootfitters. So let’s get right down to it—

Fitting narrow feet. For those of us who ski comfortably in 98mm last boots at 315BSL the Quadrant is a difficult fit. A size 28 at 320BSL isn’t impossibly long for feet that usually fit 315mm BSL—my Radiums, for other reasons of poor design (a death-tight toebox) were 325mm—but with a 105mm last there is enough play in the boot for the foot to shift off axis and torque inside the shell. In powder this is less noticeable, but as soon as conditions demand precise control and/or the big planks come out, the fit is too weak to deliver high-end performance.

Obviously this is particular to one’s foot, but Black Diamond’s proportional last sizing is something of a gamble, in assuming that a longer foot is also a wider foot. Overall, there is too much forefoot volume in the boot, and increasing buckle pressure only cramps the overlap, having little effect on volume while guaranteeing cold feet and tingly toes, as the overlap cuts off circulation.

Overall, I wouldn’t hesitate to ride this boot, especially for those with big, wide feet. But even the monstrous need a boot that can be fitted to the foot, rather than a boot that allows the foot to fit it. Does this make sense? Boots should be made to fit; if a shell fits because it’s so large it will fit anything, then the boot will display signs of ill-fitting down the road as the liner blows out and the shell develops its flex pattern in relation to use. I’m not saying this will be everyone’s experience, but I am surprised that BD has gone with such a proportionately large shell when designing what is otherwise the lightest and stiffest touring boot to yet hit the market. But I digress; for the performance of the boot alone it is worth figuring out a way to make the shell work if you have narrow-to-average sized feet. The Quadrant is definitively the best overlap design to hit the market at this weight.