Ski: 2020-2021 Kastle FX106 HP, 184 cm
Days Skied: 7
Available Lengths: 168, 176, 184, 192 cm
Blister’s Measured Tip-to-Tail Length: 183.9 cm
Stated Weight per Ski: 2000 grams
Blister’s Measured Weight per Ski: 2079 & 2105 grams
Stated Dimensions: 137-106-125 mm
Blister’s Measured Dimensions: 137.6-105.5-124.6 mm
Stated Sidecut Radius (184 cm): 20.4 meters
Measured Tip & Tail Splay (ski decambered): 59 mm / 20 mm
Measured Traditional Camber Underfoot: 2 mm
Core: Poplar/Beech/Paulownia + Carbon & Fiberglass Laminate
Base: Sintered graphite
Factory Recommended Mount Point: -12.15 cm from center; 79.8 cm from tail
[Note: Our review was conducted on the 19/20 FX106 HP, which returns unchanged for 20/21.]
For the 19/20 season, Kastle overhauled their “freeride” skis with the introduction of a revamped “FX” lineup. While the old Kastle BMX and the old (pre-19/20) FX95 HP had previously served as the brand’s freeride skis, the new 19/20 FX skis are quite different. The new FX line consists of the FX86, FX 96 W, FX96 HP, FX106 HP, and the FX116, many of which return unchanged for 20/21, including the FX106 HP.
We’re reviewing the FX106 HP, the mid-fat ski in the group that’s designed to handle a bit of everything, with an emphasis on backcountry and off-piste performance. The entire FX line is an interesting move for Kastle, as they’re going in a very different direction from the old BMX and previous FX skis of the past.
Check out our video First Look for a quick rundown on this ski, and below we’ll dive into more detail.
What Kastle says about the FX106 HP
“The FX106 HP is made for the backcountry and when teamed up with the FREETOUR 12 2.0 binding is also designed to be used as a touring ski. The 3D shape, triple wood core and carbon-fibreglass wrapped core of the lightweight TRI technology results in maximum transfer of power, stability and perfect float. Combined with Hollowtech 3.0 this ski raises the bar in terms of minimised weight and maximised downhill performance.
With the FX106 HP, epic lines and big drops are a breeze for Freeride World Tour Champion Lorraine Huber. This HP (high performance) ski is the weapon of choice for pros like Lorraine, from the first lift right through to the last ride of the day.”
The FX106 HP is designed to excel off-piste, and Kastle’s also making a point to emphasize pairing it with their Freetour 12 2.0 touring binding (equivalent to the ATK Raider 2.0 12 binding). So this ski is supposed to be light enough for human-powered skiing, and yet it’s also supposed to be supportive enough for FWT athletes like Lorraine Huber. That’s not something we hear about many skis, but the FX106 HP definitely has some unique things going on with its construction, so let’s first dive into that.
The FX106 HP uses a blend of several interesting technologies and techniques in its construction.
First, it uses Kastle’s new “Tri Tech” construction, which consists of three key elements. First, the FX106 HP uses three different types of woods — poplar, beech, and paulownia. The center of the core is a poplar / beech blend, designed to offer power, rigidity, and damping due to the heavier beech wood. Then the outer portions of the core (near the edges) feature a lighter poplar / paulownia blend.
That mixed wood core is implemented in a “3D” construction where the center band of poplar / beech is thicker than the outer poplar / paulownia stringers. So, combined with the different wood types, you get a thicker, stronger core in the middle of the ski and then a lighter core near the edges.
The FX106 HP’s center band of poplar / beech is also wrapped in a carbon & fiberglass “sleeve,” designed to increase torsional rigidity and bonding strength between the different woods. For the FX86, FX96 W, & FX116, the middle core is wrapped in a pure fiberglass sleeve, while the FX96 HP and FX106 HP get a carbon & fiberglass sleeve for reportedly more power and rigidity (hence the “HP” moniker). While Kastle used to add the “HP” label to skis that featured titanal layers, none of the 19/20 FX skis feature titanal.
Finally, the FX106 HP uses Kastle’s signature “Hollow Tech 3.0,” which means the ski has core material removed from the tip / shovel and replaced with a synthetic material (the obvious green cutout at the tip) that’s designed to decrease swing weight while actually making the ski’s tips more damp.
Shape / Rocker Profile
While the FX skis use a much lighter construction than the old BMX skis, their shapes haven’t drastically changed over the years. Overall, the FX106 HP looks pretty similar to the old Kastle BMX 105 in terms of shape. The FX106 HP has a pretty tapered shovel and a significantly less tapered tail.
The FX106 HP isn’t as tapered (particularly in the tail) as some skis like the Rossignol Soul 7 HD or Dynastar Legend X106, but the FX106 HP is more tapered (particularly in the shovel) than more traditionally shaped skis in this width like the Liberty Origin 106, Black Crows Corvus, and Icelantic Nomad 105.
The FX106 HP’s rocker profile is pretty different from the old BMX 105. The FX106 HP has a fairly deep, but pretty low-slung tip rocker line and a significantly shallower tail rocker line. The BMX 105 had deeper tip and tail rocker lines that started rising more abruptly.
The FX106 HP’s tip rocker line is similarly deep vs. the Salomon QST 106, but the QST 106’s tip rises much more abruptly and has much more tip splay. Similar story in the tail, but the QST 106 also has a deeper tail rocker line. The Line Sick Day 104 is fairly similar compared to the QST 106 when it comes to rocker profile — deeper rocker lines and rocker lines that rise quicker than the FX106 HP.
Compared to the Rossignol Soul 7 HD, the FX106 HP has a deeper tip rocker line, but the Soul 7 HD’s tip rises much more abruptly. The Soul 7 HD’s tail rocker line is also a bit deeper and it has slightly more tail splay.
All in all, the FX106 HP’s rocker profile is nothing super out of the ordinary for a ~106mm-wide, directional freeride ski. There are lots of skis in this class with deeper rocker lines and more tip and tail splay, but there are also some with even less rocker and splay.
Here’s how we’d characterize the flex pattern of the FX106 HP:
In Front of Toe Piece: 8-9
Behind the Heel Piece: 9.5-9
The FX106 HP has a very directional flex pattern with very soft tips and significantly stiffer tails. The hollowed-out portion of the FX106 HP’s tips is very soft, but it then ramps up pretty quickly as you move to the middle of the ski. The middle is very strong, it stays strong behind the bindings, and then it smoothly softens at the very end.
The FX106 HP’s flex pattern reminds me of the Rossignol Soul 7 HD, but the Soul 7 HD’s tips are a tiny bit softer and its tail stays a bit stiffer. Flexing the Soul 7 HD vs. the FX106 HP, the FX106 HP’s flex-pattern transition in the shovel feels a bit smoother (doesn’t feel very hinge-like).
The recommended mount point on our pair of the FX106 HP comes in around -12 cm from true center, which is very far back.
When I measured the FX106 HP’s mount point, I triple checked it since I had just measured the much heavier, more traditionally shaped & rockered Kastle MX99, which has a recommended mount point that isn’t even that far back (the MX99’s is around -9.5 cm from center).
So, combined with its shape, flex pattern, and rocker profile, the FX106 HP’s very rearward mount point makes it look like a very directional ski that will best reward a forward stance.
Given the FX106 HP’s lack of metal and use of construction elements that reduce weight, it’s not that surprising that it comes in at a fairly low weight of around 2092 grams per ski for the 184 cm length. That’s not nearly as light as most dedicated touring skis, but it’s also significantly lighter than many other “freeride” skis in this waist width.
What is interesting is that the old Kastle BMX skis and the old FX95 HP were definitely not light skis. The BMX 105 (non-metal version) came in around 2271 grams per ski for the 189 cm length, which is far heavier than the FX106 HP. So, again, Kastle seems to be going in a pretty different direction with their new FX skis.
The FX106 HP’s weight puts it in the same class as many skis we’d classify as “50/50” skis — light enough for touring, but not so light that we wouldn’t want to ski them in the resort. We’ll be interested to see how the FX106 HP stacks up against both heavier and lighter skis in its class.
For reference, here are a number of our measured weights (per ski in grams) for some notable skis. Since Kastle is marketing the FX106 HP for both lift-accessed and human-powered skiing, we’re listing both resort- and touring-oriented skis. Keep in mind the length differences to try to keep things apples-to-apples.
1605 & 1630 Line Vision 108, 183 cm (19/20)
1606 & 1641 Blizzard Zero G 105, 188 cm (19/20)
1642 & 1651 Renoun Citadel 106, 185 cm, (18/19)
1642 & 1662 Atomic Backland 107, 182 cm (18/19–19/20)
1660 & 1680 Moment Deathwish Tour, 184 cm (19/20)
1692 & 1715 Moment Wildcat Tour 108, 184 cm (18/19–19/20)
1706 & 1715 Volkl BMT 109, 186 cm (17/18–19/20)
1733 & 1735 Blizzard Zero G 108, 185 cm (17/18–18/19)
1745 & 1747 4FRNT Raven, 184 cm (16/17–18/19)
1752 & 1771 Amplid Facelift 108, 189 cm (18/19–19/20)
1755 & 1792 Line Sick Day 104, 179 cm (17/18–19/20)
1787 & 1793 Fauna Pioneer, 184 cm (19/20)
1787 & 1806 WNDR Alpine Intention 110 (cambered), 185 cm (19/20)
1806 & 1862 Armada Tracer 108, 180 cm (19/20)
1814 & 1845 Elan Ripstick 106, 181 cm (17/18–19/20)
1825 & 1904 Black Crows Corvus Freebird, 183.3 cm (17/18–19/20)
1843 & 1847 Head Kore 105, 189 cm (17/18)
1848 & 1903 Line Sick Day 104, 186 cm (17/18–19/20)
1849 & 1922 Elan Ripstick 106, 188 cm (17/18–19/20)
1853 & 1873 WNDR Alpine Intention 110 (reverse camber), 185 cm (19/20)
1923 & 1956 DPS Alchemist Wailer 106, 189 cm (17/18–18/19)
1950 & 1977 Blizzard Rustler 10, 188 cm (17/18–18/19)
1970 & 1979 Atomic Backland FR 109, 189 cm (17/18)
1996 & 2012 Dynastar Legend X106, 188 cm (17/18–19/20)
2005 & 2035 Liberty Origin 106, 187 cm (19/20)
2011 & 2028 Moment Wildcat 108, 184 cm (19/20)
2030 & 2039 Rossignol Soul 7 HD, 188 cm (17/18–19/20)
2079 & 2105 Kastle FX106 HP, 184 cm (19/20)
2097 & 2113 DPS Alchemist Wailer 106, 189 cm (19/20)
2101 & 2104 Fischer Ranger 102 FR, 184 cm (18/19–19/20)
2110 & 2119 Moment Wildcat 108, 190 cm (19/20)
2112 & 2125 4FRNT MSP 107, 187 cm (18/19–19/20)
2120 & 2134 Blizzard Rustler 10, 188 cm (19/20)
2143 & 2194 ON3P Wrenegade 108, 184 cm (18/19–19/20)
2165 & 2211 K2 Mindbender 108Ti, 186 cm (19/20)
2165 & 2219 Icelantic Nomad 105, 191 cm (19/20)
2177 & 2180 Moment Commander 108, 188 cm (19/20)
2182 & 2218 Nordica Enforcer 110, 185 cm (17/18–19/20)
2188 & 2190 Prior Northwest 110, 190 cm (19/20)
2190 & 2268 Armada ARV 106Ti LTD, 188 cm (18/19–19/20)
2202 & 2209 Shaggy’s Ahmeek 105, 186 cm (19/20)
2218 & 2244 Volkl Mantra 102, 184 cm (19/20)
2232 & 2244 ON3P Woodsman 108, 187 cm (19/20)
2233 & 2255 Nordica Enforcer 104 Free, 186 cm (19/20)
2241 & 2295 4FRNT Devastator, 184 cm (14/15–18/19)
2250 & 2307 Argent Badger, 184 cm (19/20)
2283 & 2290 ON3P Wrenegade 108, 189 cm (18/19–19/20)
2312 & 2386 Prior Husume, 188 cm (17/18–19/20)
2318 & 2341 J Skis The Metal, 186 cm (16/17–18/19)
2321 & 2335 Fischer Ranger 107 Ti, 189 cm (19/20)
2376 & 2393 Blizzard Cochise, 185 cm (15/16–19/20)
Some Questions / Things We’re Curious About
(1) The FX106 HP is a fairly light ski, but it’s also a uniquely constructed ski. So will the FX106 HP’s construction make it notably more stable than similarly light skis, or even heavier ones?
(2) The FX106 HP has more taper and rocker than many of Kastle’s other skis, so how loose and easy to pivot will it be, and how solid will it feel on edge?
(3) The tips and shovels of the FX106 HP are quite soft, but it has a stiff midsection and a stiffer tail, so how forgiving vs. demanding will it feel?
(4) Given its very rearward mount point, we expect the FX106 HP to reward a very forward, driving stance. But how will it feel with the bindings mounted in front of its recommended line?
Bottom Line (For Now)
The new Kastle FX106 HP seems like a new step for the brand — it’s a fairly light ski with a modern shape, rocker profile, and construction. But Kastle is claiming that the FX106 HP can hold up to aggressive, freeride-style skiing, so we’ll be getting the ski on snow ASAP to see how it compares to the other options in this category.
Sam Shaheen and I both spent time on the FX106 HP this past season at Crested Butte, and we came away with similar impressions. We were able to get it in both very soft and quite firm conditions to get a good idea of the versatility of this wider all-mountain ski, so let’s get to it.
Soft Chop / Powder
We didn’t get the FX 106 HP into a bunch of truly untracked runs, but I do think this ski will float very well for its width. It doesn’t have a super deep tip rocker line or a dramatic amount of tip splay, but the FX106 HP’s very rearward mount point (-12 cm from true center) and super soft tips never had me feeling any tip dive, even when driving its shovels hard into deep patches of soft chop.
I was a bit worried that the FX106 HP’s hollowed-out, soft tips might fold up during high-speed impacts, but I never experienced that. Even when skiing quite fast and aggressively in soft chop, the majority of the FX106 HP feels quite strong, and encourages pushing it hard through soft, choppy snow. Due to its mount point, I was far enough back on the ski that I never felt like I was really leaning on the soft ends of the tips, but rather, its supportive midsection. This is kind of a cool combination, as I seemed to get the flotation benefits of the soft tips without much of any downside.
Overall, I’d say that the FX106 HP feels slightly above average in terms of its stability-to-weight ratio. The 184 cm version’s average weight per ski is just under 2100 grams, which is neither super light nor very heavy by today’s standards. It’s definitely not a ski that feels like it has enough mass / momentum to just plow through patches of soft snow with little effort on your end. But if I stay over the shovels and take advantage of its stronger-flexing midsection, I can ski the FX106 HP very hard in soft chop.
As will be a theme, I also liked how much energy the FX106 HP returned back when I was pushing it hard. Even in soft chop, I could load up the ski and get launched from turn to turn.
Firm Chop / Crud
For those who loved the old Kastle BMX skis, you will not find the same suspension and smooth feel in the FX106 HP — the FX106 HP is far lighter than those skis, so this isn’t a surprise.
But if you found the old BMX skis to feel sluggish rather than smooth and damp — or you just aren’t that interested in skiing super fast when the conditions aren’t prime for doing so — the FX106 HP makes more sense.
Given how light it is, I think the FX106 HP does an admirable job of smoothing out rough snow. You’re certainly still gonna have a pretty good idea how rough the snow is underneath these skis (it does not make it disappear like heavier skis can), but the FX106 HP does not feel as harsh as some of the slightly lighter options out there.
Suspension / damping aside, the FX106 HP’s other potential upside (depending on your skiing style) is how hard you can drive its shovels and how precise it feels on edge. In very rough snow, being able to put a lot of pressure on a ski’s shovels can help make it feel more composed — especially with lighter skis. With light skis with more forward mount points, you’re sometimes forced to ski them very neutral / centered and therefore don’t have as much leverage over the tips as they get knocked around. Not so with the FX106 HP — that -12 mount point let me try to emulate my racing friends’ techniques as much as I could muster.
Of course, many people get along just fine with skis that let them casually pivot and slide through rough snow from a centered stance — not everyone wants to ski hard through these more challenging conditions. And for those people, I don’t think the FX106 HP makes as much sense, since (1) you won’t be taking advantage of its directional design and (2) it’s more difficult than more centered-stance skis when you decide to ski from a more centered stance.
The FX106 HP also carves really well, which can help in wide-open terrain with fairly shallow, firm chop. We’ve talked about skis being “too loose” to the point that it’s difficult to keep them tracking down the fall line in rough snow. The FX106 HP is certainly not one of those skis — while I could release its tails when I wanted to, it’s a ski that prefers to be on edge and headed downhill.
Sam and I were both really impressed by the FX106 HP’s carving capabilities. The ski came with a factory tune that was definitely sharper than average, and with the factory tune, it was one of the best ~106mm-wide skis we’ve used in terms of edge hold. (We’re asking Kastle about the details on the factory tune and will update this when we get that info.)
However, we both had a hard time feathering turns on the FX106 HP with its factory tune, so we lightly detuned the rockered portion of its tails and much preferred the ski with that slight tail detune. We could break it free from a carved turn much easier (whether on or off piste) without feeling like we lost very much edge hold.
While the FX106 HP holds an edge really well, its turn initiation isn’t as instant as skis that have less tapered tips. The FX106 HP doesn’t immediately pull you across the fall line on groomers, but once you get some speed going, it is pretty easy to lay it over on edge. The 184 cm’s 20.4-meter stated sidecut radius feels accurate on snow — slalom turns are difficult, but it felt comfortable making just about any turn shape larger than that.
And again, if you’re pushing this ski pretty hard, it produces lots of energy / rebound / pop / whatever you want to call it when a ski launches you out of the exit of a turn.
Moguls, Trees, & Tight Terrain
How easy or difficult (and just generally “fun”) the FX106 HP feels to you in tighter terrain will definitely come down to your skiing style and ability level.
I would not recommend this ski to beginners, and I think many intermediates may still have a hard time on it. Mostly because of two things:
First, this is not a super loose ski. Skiers with good technique who stay over the shovels of their skis will find it pretty easy to release its tail (especially after a light detune). But if you’re prone to skiing backseat or even centered in tight spots, the FX106 HP is not going to be very easy to pivot, and it may send you going downhill faster than you’d like.
The second, slightly less important thing is that the FX106 HP’s tail feels pretty strong on snow. It’s not extremely punishing, and I think its minimal tail rocker line also plays into this (since you’re engaging a lot of tail). But the main point is that this isn’t a ski for tail-gunning through bumps and trees.
But for advanced and expert skiers with a directional skiing style, there’s a lot to like about the FX106 HP in tight — and especially tight and steep — terrain.
Despite its very rearward mount point, I never felt like the FX106 HP’s swing weight was notably heavier than similarly light skis with more forward mount points (which I’d assume is mostly due to Kastle’s “Hollowtech” tips). This, combined with the energetic feel of the ski, makes it feel quick and nimble in tight spots.
As in other terrain, the FX106 HP feels better the harder you ski it. If you’ve got good technique, it’s still pretty easy to slowly pick your way through tight spots on this ski, but I definitely had the most fun on this ski when I was trying to hack my way down steep bumps and trees as fast as possible.
Throughout my time on this ski, it kept making me think of the OG Hot Doggers. Yes, it’s a directional ski, but it’s one that’s a ton of fun to ski with an aggressive, yet active skiing style — drive its shovels hard into a trough, load up the tails, do a big airplane turn over the top of a bump, repeat. If that sounds like your style, the FX106 HP definitely stands out in the current market.
We spent most of our time on the FX106 HP with it mounted on its recommended line (-12 cm from true center). I tend to get along best with skis that have mount points closer to center, so I also tried it with the bindings at +2 cm in front of the line (around -10 cm from true center).
Overall, I didn’t notice a big difference between those two mount points. The FX106 HP is a very directional ski overall and I think directional skiers will be just fine with it mounted on the recommended line. If you want more tail behind you for landings or it just feels weird to you to have so much ski in front of you, bumping 2 cm in front of that line is a safe bet. I didn’t notice much of a downside apart from the tail being slightly more punishing if I got backseat.
Who’s It For?
Advanced and expert skiers who prefer a directional, driving-the-shovels stance and who prioritize quickness and energy over flat-out stability and an ultra-smooth, damp feel.
I wouldn’t recommend the FX106 HP to skiers who often find themselves in the backseat, or who prefer to ski with a very neutral, centered stance. And if you’re a directional skier who wants a ski that’s super loose and easy to pivot, this isn’t your ski. Finally, if you mostly want a ski that will blast through any sort of snow with little feedback, you should look to much heavier options.
But if you prefer a slightly lighter, quicker ski over a super stable one, the FX106 HP is a strong contender. It’s very versatile across a wide range of conditions, carving really well for its width while also offering very good flotation in deeper snow. It lets you drive it very hard through the shovels (and often demands that you do that), which can help it feel more stable in rough snow vs. similarly lightweight skis. And if you’re a directional skier who also likes to get your skis airborne between turns, the FX106 HP is a great choice.
The Kastle FX106 HP is a ski that bridges the gap between many of the lighter, easier all-mountain skis and the much heavier, more sluggish ones. Under the feet of a skier with good technique, the FX106 HP is quick and lively, yet can be skied quite hard for how light it is.
Deep Dive Comparisons
Become a Blister Member or Deep Dive subscriber to check out our Deep Dive comparisons of the FX106 HP to see how it compares to the Rossignol Soul 7 HD, Head Kore 105, DPS Alchemist Wailer 106 C2, Rossignol BLACKOPS Sender & Sender Ti, Black Crows Corvus, Black Crows Atris, Fischer Ranger 102 FR, Fischer Ranger 107 Ti, Line Sick Day 104, Moment Wildcat 108, 4FRNT MSP 107, Blizzard Rustler 10, Liberty Origin 106, Salomon QST 106, Nordica Enforcer 104 Free, & K2 Mindbender 108Ti.