Ski: 2025-2026 4FRNT Sinister, 186 cm
Available Lengths: 179, 186, 192 cm
Blister’s Measured Tip-to-Tail Length (straight-tape pull): 183.9 cm
Stated Weight per Ski (186 cm): 2336 grams
Blister’s Measured Weight per Ski (186 cm): 2276 & 2358 grams
Stated Dimensions: 134-113-125 mm
Blister’s Measured Dimensions: 133.5-112.5-124.5 mm
Stated Sidecut Radius (186 cm): 22 meters
Measured Tip & Tail Splay (ski decambered): 74.5 mm / 44 mm
Measured Traditional Camber Underfoot: 3.5 mm
Core Materials: aspen/maple + titanal (partial layer) + fiberglass laminate
Base Material: sintered
Factory Recommended Mount Point: -4.2 cm from center / 87.7 cm from tail
[Editor’s Note: Our “First Looks” are our way of getting you information sooner on some of the products we’re reviewing, including our measured specs and the details from the manufacturer. Once we’ve started testing a given product, we detail our on-snow impressions in our Flash Reviews and our annual Winter Buyer’s Guide. When we’re able to spend extensive time testing a given product, we publish our in-depth Full Reviews and Deep Dive comparisons.]
Intro
Back at Blister Summit 2025, 4FRNT brought a mysterious new ski to their tent. Turns out, it was a prototype of Stinius Skjøtskift’s pro model, and now that ski is available as the 4FRNT Sinister.
We sat down with Stinius and 4FRNT brand manager, Sam Kimmerle, to get the whole backstory on the Sinister; how it combines elements from nearly all of 4FRNT’s other skis; what it was like for Stinius to do the initial prototyping with the king of tinkering, Eric Hjorleifson, and more.
Now that we have a Sinister in for long-term testing, we’ve published our video of that conversation, as well as our Flash Review of the Sinister, where we go into our initial on-snow impressions.
We’ll be spending a lot more time on this ski in the future, but in the meantime, here are more details on the final design that Stinius settled on to suit his skiing style, which blends aspects of freestyle, modern freeride, and traditional directional charging.
What 4FRNT says about the Sinister:
“The Sinister is the first promodel ski from style master Stinius Skjøtskift—built to match his smooth, creative approach to skiing big terrain. Featuring camber underfoot, smooth tip and tail rocker, and a mid-fat waist. The Sinister floats, slashes, and remains stable as hell, no matter what speed you choose.
The Aspen core brings ample energy that gets you higher off the ground and makes your turns smoother from edge to edge. We laced the Sinister up with a reinforced Titanal Stomp-Zone underfoot to deliver rock-solid stability and power when you need it. From pillow stacks to bulletproof landings, this ski eats it up.
Forged in the mountains from Norway to British Columbia, the Sinister was built to turn heads.”
Construction
The Sinister is built around an aspen / maple wood core that’s supplemented with H-shaped metal layers meant to add torsional stiffness / edge grip around the middle, without making the ski overly stiff or precise at the ends. The Sinister also features 4FRNT’s neoprene tip inserts for added damping, and a sintered base.
Shape & Rocker Profile
Up front, the Sinister’s tip shape and tip rocker profile are pretty reminiscent of 4FRNT’s Renegade. Unlike the reverse-camber Renegade, though, the Sinister does feature camber through the middle of the ski, and the Sinister has more of a truly twinned tail that’s somewhat reminiscent of 4FRNT’s Inthayne.
Flex Pattern
Here’s how we’d characterize the flex pattern of the Sinister:
Tips: 5.5-6.5
Shovels: 6.5-8
In Front of Toe Piece: 8.5-10
Underfoot: 10
Behind the Heel Piece: 10-9
Tails: 8.5-7
This is a pretty strong ski overall. The ends of the rockered portions of its tips and tails are fairly soft, but the rest of the ski feels pretty stout. The back half of the ski also feels a bit stiffer overall than the front.
Sidecut Radius
At 22 meters for the 186 cm length, the Sinister’s stated sidecut radius isn’t quite as long as the 4FRNT Renegade’s, but it’s a tad longer than some of 4FRNT’s more freestyle-focused models, such as the Devastator.
Mount Point
The recommended mount point of our Sinister measures about -4 cm from true center. That’s in line with many freestyle-focused models, and closer to center than most directional skis.
Weight (and Comparisons)
Our 186 cm Sinister averages out to weigh a bit over 2300 grams per ski. It’s not the absolute heaviest ski in its class, but it’s notably heavier than 4FRNT’s Renegade and Inthayne. From our perspective, this makes sense, given that the Sinister is meant to offer better suspension and stability in rougher conditions (i.e., this isn’t a ski designed solely for untracked pow).
For reference, here are some of our measured weights (per ski in grams) for some notable skis. As always, keep in mind the length and width differences to try to keep things more apples-to-apples.
1710 & 1744 Atomic Bent Chetler 120, 184 cm (18/19–23/24)
1808 & 1809 Line Pescado, 180 cm
1820 & 1835 ARV 116 JJ UL, 185 cm
1826 & 1845 Salomon QST X, 178 cm
1863 & 1872 Atomic Bent 110, 188 cm
1870 & 1895 Faction La Machine 5, 186 cm
1905 & 1919 J Skis Slacker, 188 cm
1927 & 1928 Head Oblivion 116, 181 cm
1941 & 1989 Atomic Bent Chetler 120, 192 cm
1947 & 1981 Faction La Machine 5 Max, 192 cm
1948 & 1957 RMU Professor 111, 188 cm
1973 & 1997 Salomon QST X, 184 cm
1998 & 2024 Head Oblivion 116, 189 cm
1998 & 2026 Armada ARV 112, 185 cm
2000 & 2047 Salomon S/Lab QST Blank, 178 cm
2026 & 2118 Icelantic Nomad 112, 188 cm
2027 & 2052 K2 Reckoner 112, 184 cm (20/21–23/24)
2043 & 2046 4FRNT Inthayne, 188 cm
2062 & 2080 Whitedot Ragnarok ASYM, 190 cm
2070 & 2103 K2 Reckoner 110, 184 cm
2078 & 2091 Faction Studio 3, 184 cm
2086 & 2088 Nordica Unleashed 114, 186 cm
2086 & 2125 RMU Apostle 114, 184 cm
2118 & 2124 Black Crows Nocta, 190.6 cm
2122 & 2151 Whitedot Altum 114, 187 cm
2127 & 2161 RMU Professor 121, 188 cm
2145 & 2165 Nordica Unleashed 114, 191 cm
2147 & 2286 Prior CBC, 184 cm
2163 & 2166 Moment Wildcat, 184 cm
2176 & 2185 K2 Reckoner KF, 184 cm
2187 & 2215 Salomon S/Lab QST Blank, 186 cm
2196 & 2211 Rossignol Sender Free 110, 184 cm
2212 & 2215 Armada ARV 116 JJ, 185 cm
2216 & 2246 Meier Leeper, 185 cm
2240 & 2250 Volkl Revolt 121, 184 cm
2256 & 2271 Dynastar M-Free 112, 183 cm
2259 & 2279 Black Crows Anima, 189.2 cm
2260 & 2293 Line Bacon 115, 188 cm
2276 & 2358 4FRNT Sinister, 186 cm
2318 & 2322 Line Blade Optic 114, 186 cm
2318 & 2377 Prior Northwest 116, 190 cm
2328 & 2370 Rossignol Sender Free 110, 191 cm
2334 & 2353 ON3P Billy Goat 118, 186 cm
2371 & 2375 Moment Wildcat, 190 cm
2377 & 2394 ON3P Jeffrey 118, 186 cm
2404 & 2405 Dynastar M-Free 112, 190 cm
2420 & 2576 Heritage Lab HB122, 189 cm (23/24–24/25)
2423 & 2446 K2 Reckoner 124, 189 cm
2438 & 2492 Rossignol Blackops 118, 186 cm (19/20–23/24)
2443 & 2449 Heritage Lab HB122 v2, 190 cm
2457 & 2533 Rossignol Sender Free 118, 186 cm
2534 & 2543 Heritage Lab FR110, 193 cm
Some Questions / Things We’re Curious About
(1) The Sinister’s rocker profile and shape suggest it’s an ultra-surfy and playful ski, but its weight and metal layers suggest something else. So, how well does it blend those often competing design elements / priorities?
(2) Stinius’s style isn’t easy to define, so what sorts of skiers and skiing styles will his promodel ski best suit?
(3) How will the Sinister compare to other reference points in this class of freeride skis, such as the Rossignol Sender Free 110, Dynastar M-Free 112, and Volkl Revolt 114?
Bottom Line (For Now)
The 4FRNT Sinister is a very intriguing ski on paper. It’s got the weight and construction of some metal-laminate chargers, but its rocker profile, shape, and mount point all point toward it being a playful and freestyle-friendly setup. We’re looking forward to logging many laps on it in the future to hone in on what makes it stand out on snow, and what types of skiers ought to keep it in mind.
Get More Info: Our Flash Reviews & Winter Buyer’s Guide
BLISTER+ members and those who purchase our Digital Access Pass can check out the Flash Review below to read our initial on-snow impressions. Don’t have access? Get our Digital Access Pass to read all of our Flash Reviews, Deep Dive comparisons, and our digital Buyer’s Guides. Or, even better, become a BLISTER+ member to get that + the best worldwide Outdoor Injury Insurance, exclusive deals and discounts on skis, personalized gear recommendations from us, the print version of our Winter Buyer’s Guide, and much more.
On that note, you can also get our thoughts on 350+ skis and hundreds of other snowsports products in our 2025-2026 Blister Winter Buyer’s Guide. BLISTER+ members and Digital Access Pass holders already have access, or you can purchase the guide on its own to get the the print copy + digital version at no extra cost, or the digital-only edition.
Flash Review: 25/26 4FRNT Sinister
The 113mm-wide, twin-tipped, metal-laminate Sinister isn’t your typical freeride ski, but it’s shaping up to be an interesting one. Here are our initial impressions.
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