Black Diamond Shiva Mx

The other problem was the approximately 18” of extra cord that was left over after tightening the laces. I experimented with several different ways to tuck the excess cord into the boot, but there was never a clear way to secure it. Tucking it into the boot would cause the cord to dig into my shin, which did not really work. There is Velcro on the back of the tab at the end of the cord, so I am guessing you are supposed to attach it somehow to the power strap after wrapping it around the top of the outside of the boot. Even when I used the power strap and Velcro tab, there was extra cord around the boot that would move around during the day. With the Booster Strap, I ended up wrapping the cord around the top of the boot and tucking it under the strap. Still, this would move around and require me to adjust the loose cord occasionally.

review of the Black Diamond Shiva Mx ski boots, Blister Gear Review
Lacing System on the Shiva SMx Liner

Overall, I think the Shiva Mx’s new liner is a big improvement over the previous one. I’m not tempted to go back to the Boa system again, but I would like to see Black Diamond tweak the current lacing system on the Mx liner.


The buckles on the Shiva Mx are a lower profile than those on the Shiva, which I have appreciated during hikes and rocky scrambles. The upper buckles no longer have metal extensions for touring, which I did not find myself using on the previous boot anyway.

Uphill Performance

Black Diamond advertises that the Shiva Mx as having 40 degrees of flexion in touring mode. While I have no way to measure this number precisely, the Shiva Mx definitely has a greater range of forward motion compared to the Shiva, which has a stated range of 20 degrees.

In touring mode, both models have a similar aft flex. While the Shiva Mx has deeper forward flexion, it also has a much smoother flex than the Shiva. This translated into a really nice touring experience, as I never felt inhibited by the boot in my stride.

One of my favorite things about this boot was that I never experienced any blisters while touring. Not one. I made a claim in my review of the Shiva that I believed “blisters on my feet are unavoidable” and that no other boot would solve the problem. I am pleased to say that I have proved myself wrong. Really, this just underscores the importance of finding a boot that works with your foot shape, then getting to a good bootfitter to dial things in, making sure your boot is neither too tight nor too loose for touring.

Because I am skiing the majority of my days inbounds, I decided that additional weight would be a compromise I was willing to make if it meant I had a boot that could still be skied aggressively. The Shiva Mx is slightly lighter that the Shiva (1.85kg vs. 1.9kg, Black Diamond’s stated weights), so I really didn’t notice a huge difference on the skin track. I did switch over from Marker Baron bindings to Dynfit TLT Radical bindings early on in the season, which helped reduce the effort significantly while touring. I honestly did not mind the extra weight of the boots once my bindings were so much lighter. If used in conjunction with frame-style AT bindings that are generally heavier (Marker Duke/Baron, Salomon Guardians, etc.), the boots will certainly feel like a lot on longer days, or on multiple-day hut trips.

Swappable Soles

The swappable sole system is easy to use, but takes a little bit of time. Although I greatly appreciate having alpine and AT / tech compatible soles, having a “one-boot quiver” was tedious when I would alternate resort and backcountry days and would need to swap the soles each night. At this point, after fifteen days in the backcountry, a few of which were during the summer months and involved rock scrambling, I have worn my AT soles completely through the rubber and down to the plastic in the front. Although it should not be too difficult to replace the soles, I was surprised at how quickly they deteriorated.

The switch between ski/walk mode has not changed much, and is easy to use with mittens or gloves. There was one instance where I was getting ready to drop into a relatively steep line after skinning up, and my boots would not click back into ski mode. I spent about ten minutes trying to get it to work, which included taking the shells off, but had to resort to buckling the boots as tight as they could and skiing down in walk mode. It was somewhat freaky, but I was lucky that there was not a ton of exposure and that this only happened once.

Downhill Performance

Not only was I impressed with how well the Shiva Mx worked for me while touring, but I also found it to perform really well while skiing. The stated flex of the Shiva Mx is 110, and while these numbers can be quite arbitrary across brands and models, I felt like it was actually accurate within the range of AT boots I have skied. (All the race boots I have skied have been stiffer.) For example, the stated flex of the Dynafit Gaia is 120, and I found it to be stiffer than the Shiva Mx; however, the Gaia’s plastic had a deadened sort of quality the prevented a lively response through the turn.

On the other hand, the 100 Shiva feels soft in comparison to the Shiva Mx, but it doesn’t necessarily have a smooth flex; it flexes evenly until about halfway, then almost collapses at the end. It is also feels quite a bit softer laterally than the Mx.

The Shiva Mx falls between the Gaia and the older Shiva in terms of stiffness, but I have also really appreciated the way the boot flexes: fluidly and evenly. The added stiffness allowed me to ski more aggressively than I could in the Shiva, and with a livelier response, I could generate more energy in my turns than I could in the Gaia. I personally would be psyched if Black Diamond made the boot a touch stiffer without losing its reactive character, but overall, I was impressed with Shiva Mx’s flex for an AT boot.

I spent most of my ski career in Nordica Dobermann or Rossignol Radical WC 110 race boots, and I have yet to find an AT boot that can recreate a similar experience while ripping down groomers or powering through chop. However, I never felt that the Shiva Mx inhibited me from laying over into a high speed carve or making high angle turns. There isn’t the same amount of power or energy as a race boot, but it is still totally possible and really fun. And of course, it is much more enjoyable to travel up in the Shiva Mx than in a race boot….

On a recent day at Taos, I split my time skiing bumped-up Reforma and groomer laps down Porcupine, Totemoff, and Shalako. Groomers and bumps were equally fun, as I could ski aggressively and dynamically and not worry about overpowering the boot.

Julia Van Raalte reviews the Black Diamond Shiva Mx, Blister Gear Review
Julia Van Raalte in the Black Diamond Shiva Mx AT boot, Taos Ski Valley.

And while I felt the boot to be supportive enough, it was still forgiving if I fell into the backseat.

The only time I was not totally confident on the Shiva Mx was on really steep terrain or in challenging, crud conditions when I wanted to ski hard. There was enough stability, but not so much that I could really push myself. Still, I felt the Shiva Mx was much more solid in these conditions than the Shiva.

Final Comparisons: Black Diamond Shiva Mx vs. Black Diamond Shiva vs. Dynafit Gaia

Although I have been largely impressed with the improvements on the Shiva Mx and found it to fit and ski better than the Shiva, I would still recommend trying on both models. Narrower feet will be happier in the Shiva Mx, while the previous Shiva will suit those with a more high-volume foot.

And if you are not looking for the stiffest boot, the Shiva would be a more accessible option to intermediate or advanced ladies who want a slightly softer flex. I would not recommend the Shiva Mx to a skier who likes soft boots. And if you don’t think the Shiva Mx sounds stiff enough, the Gaia could be the way to go, though the Gaia does not have as lively of a flex.

Bottom Line

Like the Shiva, the Shiva Mx is a “one boot quiver” that will please those looking for a boot to use both in the resort and backcountry, without sacrificing too much in performance going down. If you are most concerned about uphill travel, I would certainly recommend going with something lighter, and if you are pretty much only skiing the resort, an alpine boot would be the better choice. However, I have found the Shiva Mx to suit my needs perfectly while touring and riding hard inbounds, and it has been the most comfortable and high performing AT boot I have used to date.

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