What makes an all mountain boot an all mountain boot one might ask. Good question.
All mountain ski boots have different requirements than race boots. Race boots are built for a fairly narrow set of circumstances: racecourses are smooth, manicured and usually on very hard snow. There is terrain to be sure but snow conditions typically remain a constant to keep the playing field level (contradiction? Could be). Race boots are dedicated to that purpose so they must have tightly focused parameters.
The requirements of all mountain skiing are quite different. One never knows to a certainty what snow conditions will be, what the topography will be over the next knoll or drop and what demands will be placed on the skier. Adaptability, versatility and a small, predictable degree of compliance are desirable characteristics along with the level of performance needed to navigate the skis through whatever uncertainty lies ahead. Ultra-precise ski boots can be detrimental for all mountain skiing.
That being said, until recently a huge majority of all mountain skiers who insist on a high performance level are skiing in race boots-many with some alterations for a wee bit of compliance. There are a number of reasons; the plastics used for race boot shells transmits the skiers energy very cleanly…this may seem a contradiction as it would infer “ultra precision” but not so. A certain amount of precision is needed for steering and control and with the glut of wide skis so many skiers favor, lateral stability is premium.
There also is the necessity for a skier to occasionally make quick moves, which, again, puts the onus on the boots to transfer input to the skis. Race boots excel at this.
Race boots are very predictable. Predictability is an asset because one must know that when a certain move is made the response is a given…regardless of terrain, snow conditions, etc.
Race boots give the skier very sharp, crisp feedback.
Given all the above, aren’t these qualities desirable in an all mountain ski boot?
The short answer is “yes”. The flip side of terrific response, however, is being bucked around because there is little or no “rebound dampening”.
“Rebound dampening”, a term borrowed from mountain biking (other sports as well), is important because race boots force the skier into a very restricted ROM at the ankles. The net effect of this is that when a boot is flexed into a turn it can be considered compressed. Once the turn is finished the energy stored comes back to the skier, i.e. rebounds.
In race boots, because of the restricted ROM and narrow design parameters, this means the skier must absorb variations in snow conditions, terrain and topography with the knees, hips, waist, torso etc., which, in instances where the terrain is not consistent and manicured, can cause the skier to look like the fan-activated-flailing-tube-guys you see at big outdoor sales.
The long answer is that, even if desirable, why wouldn’t a skier want an all-mountain ski boot that was designed as such from the ground up as long as there is no drop-off in performance?
K2 ski boots perform as advertised; there is no trade off in performance, the fit is good and the features that make them good all mountain ski boots are, like a lot of good ideas, simple and effective. They are as quick and agile as any ski boot at this level; they display good power and excellent lateral stability. There is ample horsepower balanced with just a bit of forgiveness.
First among the features of the Spyne and Spyre that distinguish K2 ski boots from others is the Energy Interlock that fixes the cuff to the lower shell. K2’s contention is that a riveted cuff vectors the forces induced by the boots’ flexing into a very confined area of the lower shell. This is what helps to create the immediacy and exactitude of typical race boots.
The Energy Interlock is a clever, simple piece of engineering that fixes the cuff to the lower (a necessity) in a way that provides high performance and because the design distributes the stresses of flexing through a greater area allowing a smooth consistent flex.
It works also because of the Powerfuse SpYne…K2’s proprietary tag for the “Y” shaped apparatus at the rear spoiler. This enhances fore/aft predictability and lateral stoutness and permits the use of somewhat softer materials throughout the rest of the shell in an attempt to make the boots easier to get into and out of.
The Energy Interlock is the connection between the upper and lower Powerfuse SpYne instead of rivets or bolts.
Given all that, K2 boots fit and ski well. The Spyne 110 and Spyre 100-the former a men’s the latter a women’s-have good stance and close fit.
The Spyne and Spyre shells have relief for usual anatomical points; ankles, navicular and 5th met. The toe box is snug but not pinched and there is good up-and-down wiggle room. Instep is in the average volume range and the heel/mid-foot is close.
K2 liners were developed in conjunction with Intuition and should be heat treated before use-they can be skied in but heating them makes the first couple days much more bearable. The liners are not the spiral wrap style but rather a conventional design with a fairly rigid upper cuff so the proximity around the lower leg remains firm.
New for K2 this season is the Pinnacle 130-essentially a Spyne/Spyre with a walk/ski mode and Tech fittings (Dynafit toe/heel) actually molded into the toe and heel lugs. The walk/ski device is incorporated into the Powerfuse SpYne so that it does not inhibit downhill skiing.
The fit and stance is similar to that of the SpYne and SpYre…think Lange LV. The Pinnacle liner is essentially the same Intuition as you’ll find in the SpYne/SpYre but for touring notches at certain flex points to allow for articulation in walk mode. The same relief points for the feets anatomy as are found in the SpYne/SpYre are also in the Pinnacle…ankles, navicular, etc.
The top strap/buckle, the Powerbuckle, is a burly power strap with a wide traditional style buckle that can be firmly secured for skiing and opened up for standing or walking without the need to readjust when snapped back down. The Powerbuckle can also be disengaged when entering or exiting the boots without loosing the correct buckle tension at the top of the boots.
I’ve skied the Pinnacle 130 on some very hard snow and on a variety of ski widths and am impressed with how well they ski…tip’em and rip’em! No weak spots anywhere-as accurate, nimble and powerful as need be.
Good shoe! Good Shoes!
Pinnacle 130 LV