95-Flex Race and Ski Mountaineering Boot
Scarpa Alien Alpine Touring Boot
The Scarpa Alien is a crossover race and ski mountaineering boot for uphill-focused skiers, aspiring racers, and anyone who counts every gram on the climb. A Carbon Grilamid LFT shell on a 99 mm last holds the weight to 870 g per boot in a 27 while a Dyneema cord and BOA closure cinches down in one action. With 72 degrees of cuff rotation behind the Speed Lock Lite mechanism, the Alien strides like a race boot and asks you to accept a 95 flex on the way down.
Expert Fit Review
Fit profile and recommendations reviewed by CCBB bootfitters.
Is This the Right Boot for You?
Best For
Uphill-focused skiers, skimo racers and ski mountaineers with narrow, low-volume feet who want race-derived weight and stride on skis 65 to 90 mm underfoot.
Consider Another Boot If
You want downhill power or a wide fit. A 95 flex on a 99 mm last with a pin-only sole is a specialist, not an all-rounder.
CCBB Boot Ratings
Uphill Efficiency
72 degrees of rotation at 870 g (size 27)
Downhill Performance
95 flex on a 99 mm race last
Walking Comfort
72 degrees of cuff rotation
Transition Speed
Single-action cord with Speed Lock Lite
Rating scale: 5 = top of its class, 4 = excellent, 3 = good, 2 = specialized or below average, and 1 = limited.
CCBB Fit Profile
Overall VolumeLow
Toe BoxNarrow
Forefoot VolumeLow
Instep HeightLow
Heel HoldExcellent
Ankle HoldGood
PunchabilityLimited
Heat MoldableYes
Why We Like It
- 72 degrees of cuff rotation is at the top of what any touring boot offers, and it is the single thing that makes long climbs in this boot feel efficient rather than restricted.
- At 870 g per boot in a 27 the Carbon Grilamid LFT shell delivers race-adjacent weight at a price well below the full-carbon race boots above it in the line.
- A single-action Dyneema cord with the BOA Fit System means one movement closes the boot, which is where transition time is actually won or lost.
- Scarpa publishes an Optimized Touring Pivot of 7 mm for this boot, so the toe can be mounted for the stride rather than to a shop default.
Best Uses
- Skimo racing and uphill training
- Fast ski mountaineering and long ascents
- Fitness laps and dawn patrol on skis 65 to 90 mm underfoot
- Skiers with narrow, low-volume feet
Bootfitter's Advice
The Alien runs 24 to 30 in whole sizes only, which is unusual and matters: there is no half size to fall back on, so a shell fit is not optional here. The 99 mm last is narrow and low over the instep, and it fits a race foot rather than an average one.
Punching is limited on this shell. Carbon-reinforced Grilamid LFT is less forgiving of large modifications than plain Grilamid, so plan the fit around the liner rather than the shell. The Tour Lite liner molds in 4 to 6 minutes. Forward lean runs 9 to 13 degrees, and the 7 mm Optimized Touring Pivot should be applied at mounting.
Fit profile reviewed by CCBB bootfitters. Final sizing should be confirmed with a shell fit whenever possible.
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Technical Specifications
Manufacturer specs · Click to expand
Fit and Construction
Weight: 870 g per boot (size 27)
Sizes: 24 to 30 (whole sizes only)
Last: 99 mm
Flex: 95
Range of Motion: 72 degrees
Shell: Carbon Grilamid LFT, a carbon-reinforced nylon
Cuff: Grilamid FG, a long-glass-fiber reinforced nylon
Tongue: Synthetic
Features and Compatibility
Walk Mode: Speed Lock Lite ski/walk mechanism
Closure: Dyneema cord with a BOA Fit System
Binding Compatibility: Pin/tech (low-tech) bindings only. The Vibram UFO sole carries no ISO norm, so the Alien is not compatible with AT/frame bindings, MNC bindings, or traditional ISO 5355 (Alpine) bindings. Scarpa specifies an Optimized Touring Pivot of 7 mm for the toe mount.
Sole: Vibram UFO sole in TOP85 compound. No ISO norm.
Forward Lean: 9 to 13 degrees
Liner: Tour Lite liner, a heat-moldable foam
Liner Mold Time: 4 to 6 minutes
Article Number: 12175/500.2
Notes: Optimized Touring Pivot of 7 mm, which belongs on the mount sheet
Compare the Scarpa Alien
Alien vs. Scarpa Alien 1.0
The Scarpa Alien 1.0 is the lighter, more race-focused boot above this one in the line, and Scarpa specifies a different Optimized Touring Pivot for it. The Alien is the crossover build: heavier, less expensive, and easier to live with for training and general ski mountaineering rather than pure racing.
Shop Scarpa Alien 1.0 boots
Alien vs. Scarpa F1 XT
The Scarpa F1 XT is the step toward downhill capability, a stiffer touring boot on a 100 mm last for skiers who want to ski a wider ski properly. The Alien gives up that flex and returns 72 degrees of rotation and 870 g per boot. Both are pin-only, so neither takes a frame binding.
Shop Scarpa F1 XT boots
Alien vs. Scarpa Maestrale RS
Opposite ends of the range. The Scarpa Maestrale RS is a 130 flex freeride touring boot at 1,570 g per boot in a 27 on an ISO 9523 sole. The Alien is a 95 flex race crossover at 870 g with no sole norm. These are not alternatives so much as different sports.
Shop Scarpa Maestrale RS boots
Common Questions
Who should buy the Scarpa Alien?
The Scarpa Alien suits uphill-focused skiers, skimo racers and ski mountaineers with narrow feet. A Carbon Grilamid LFT shell on a 99 mm last holds 870 g per boot in a 27, and 72 degrees of cuff rotation makes long climbs efficient. The 95 flex is the trade, so it belongs on skis 65 to 90 mm underfoot.
What bindings work with the Scarpa Alien?
Pin/tech (low-tech) bindings only. The Vibram UFO sole carries no ISO norm, so the Alien is not compatible with AT/frame bindings, MNC bindings, or traditional ISO 5355 (Alpine) bindings. Scarpa lists the binding system as TLT with an Optimized Touring Pivot of 7 mm, which means the tech toe should be mounted 7 mm rearward of the standard position. Bring that figure to whoever mounts your skis.
Does the Scarpa Alien fit a frame or MNC binding?
No, and this is the field worth being careful about. A compact race sole that meets no ISO norm cannot be used in a binding whose release depends on sole geometry. That rules out AT/frame bindings and MNC bindings even though those accept other Scarpa touring boots. Pin/tech only.
What is the range of motion on the Scarpa Alien?
72 degrees. Scarpa does not print the figure in the specification block on its own product page, which has led to it being reported as unpublished, but the technical manual gives 72 degrees behind the Speed Lock Lite mechanism. That is among the largest ranges available in any ski touring boot.
What foot shape fits the Scarpa Alien?
A narrow, low-volume foot. The 99 mm last is a race last and it runs low over the instep with a snug heel. It also comes in whole sizes only from 24 to 30, so there is no half size to split the difference and a shell fit is essential.
Can the Scarpa Alien be punched?
Only modestly. Carbon-reinforced Grilamid LFT is stiffer and less forgiving of large modifications than plain Grilamid, so we work the fit through the liner where possible. The Tour Lite liner is heat-moldable and Scarpa specifies a 4 to 6 minute mold.
How does the Scarpa Alien compare to a full race boot?
It is the crossover below one. The full-carbon race boots in the line are lighter and stiffer through the cuff at a considerably higher price. The Alien uses Carbon Grilamid LFT to reach 870 g per boot in a 27, which puts race-adjacent weight within reach for training and general ski mountaineering.
Our Verdict
The Scarpa Alien is a race boot you can justify owning without racing. A Carbon Grilamid LFT shell on a 99 mm last reaches 870 g per boot in a 27, the Dyneema cord and BOA close in one action, and 72 degrees of cuff rotation is at the top of what any touring boot offers. What you accept is a 95 flex, whole sizes only from 24 to 30, a narrow last, and a Vibram UFO sole that carries no ISO norm and therefore runs pin/tech bindings and nothing else. For uphill-focused skiers on narrow skis that is the right set of compromises.
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