2017-2018 Scarpa Alien RS

Paul Forward reviews the Scarpa Alien RS for Blister
Scarpa Alien RS

2017-2018 Scarpa Alien RS

Available Sizes: 24-30

Stated Flex: 95

Stated Last Width: 99 mm

Size Tested: 28.0 / 302 mm Boot Sole Length

Stated Range of Motion: 72°

Stated Weight (27.5) : 890 g

Blister’s Measured Weight
• Shells, no liners: 779 & 781 grams
• Liners (no footbeds): 209 & 210 grams
• Shells + Liners: 988 & 991 grams

Forward Lean options: 7, 9, 11, 13 degrees

Shell Material (Cuff & Shoe): Carbon Grilamid® LFT

Liner: Intuition® Cross Fit Tour

Sole: Rockered, Vibram Rubber

Tech Inserts: Dynafit-Certified Quick Step-in

Binding Compatibility: Tech Only

MSRP: $870


The Scarpa Alien RS is new for the 17/18 season, and it just might represent a significant step forward in the performance-to-weight ratio of lightweight ski touring boots.

We’ve been consistently impressed by the skiing performance of boots like the Dynafit TLT5, 6, and 7; Atomic Backland Carbon, Arc’teryx Procline Carbon Support, Salomon X-Alp S-Lab, and the Scarpa F1 Evo, and it appears that Scarpa has set their sights on creating a boot that offers similar performance to these boots, but at a significant weight savings.

In Scarpa’s words: “Maintaining the same ultralight, race-inspired touring performance as the original Alien with a stiffer, more powerful flex thanks to a carbon-infused Grilamid® shell, the all-new Alien RS still crushes the uphill and is better than ever on the way down.”

With that description and a stated flex rating of 95, it appears that Scarpa is attempting to offer the performance we’ve come to appreciate in this class of boot but with a 100 – 300 g weight savings. And considering how light these other boots are and how well they ski, a boot with the same performance and 10-30% weight savings is an impressive goal.

Weight and Comparisons

For reference, here are a few of our measured weights for some boots in the same category as the Alien RS. (All weights are in grams, and are taken with the boots’ footbeds, spoilers, and / or laces removed.)

988 & 991 Scarpa Alien RS, 28.0
1064 & 1070 Fischer Travers Carbon, 27.5
1065 & 1069 Dynafit TLT 7 Performance, 28.5
1167 & 1170 Atomic Backland Carbon, 27.5
1232 & 1232 Salomon S-Lab X-Alp, 27.5
1288 & 1286 Arc’teryx Procline Carbon Support, 27.5

So how did Scarpa reduce the weight, and what else should you know about the Alien RS?

Buckles (or Lack Thereof)

The Alien RS is the first boot I’ve ever skied that has nothing that resembles a buckle or powerstrap. The “New Speed Lock” on the Alien RS is essentially a continuous piece of high-strength, low-stretch Dyneema cord that is looped around the upper cuff and through the walk mode lever. Adjustments in tension/cuff tightness can be made by increasing or decreasing the cord length through the cam lock on the lateral side of the cuff.

Paul Forward reviews the Scarpa Alien RS for Blister
Scarpa Alien RS — Walk Mode & “Speed Lock Cam System”

The lower shell is secured through a Boa system similar to the F1 Evo or Fischer Travers Carbon.


The shell portion of the boot is also more minimal than on other boots we’ve tested. The upper cuff is impressively thick and tall for a boot in this class, but has large cutouts fore and aft for increased range of motion. The lower shell seems to involve quite a bit less material than comparable boots with very minimal plastic extending over the top of the foot/instep and instead employing a stretchy gaiter that incorporates the boa system and comes up above ankle height. In comparison to other boots in this class, the actual plastic shell of the Alien RS extends much less up and over the top of the instep.

Paul Forward reviews the Scarpa Alien RS for Blister
Scarpa Alien RS — Boa System & Lower Shell


The sole of the Alien RS looks thin, but it’s not as minimalist as the Salomon X-Alp S-Lab. It features sticky-feeling Vibram rubber and has areas of higher density rubber at the heel and toe for added durability. And Scarpa says the toe rubber is thinner to reduce weight and maximize sensitivity while climbing.

Paul Forward reviews the Scarpa Alien RS for Blister
Scarpa Alien RS — Sole

Adjustable Forward Lean

Of the other boots we’ve reviewed in this class, several have no forward lean adjustment (e.g., Arcteryx Procline and Salomon S-Lab X-Alp) while others have 2 settings (e.g., Atomic Backland and Dynafit TLT7). With four different forward lean positions, the Alien RS might be appealing for those who haven’t found the position they like in existing boots.


Like all of Scarpa’s touring boots, the Alien RS features a custom Intuition liner designed specifically for this particular model. We’ve had some issues with liners on many boots in this class, and have found some of them almost unusable (I’m looking at you, Dynafit TLT7). Upon initial look and feel, the liner of the Alien RS appears to be the best liner we’ve seen in this class of boot, with enough thickness for support and comfort, while at the same time remaining simple, light, and low profile.

Paul Forward reviews the Scarpa Alien RS for Blister
Scarpa Alien RS — Intuition Cross Fit Tour Liner

Tech Fittings

Scarpa continues to build its touring boots with Dynafit’s Quick Step-in fittings, and we remain big fans of this option. Not only are the fittings Dynafit-certified for standardized dimensions, but they are easier to click into for all forms of tech bindings that we’ve used.

Fit & Sizing

As we say all the time, fit is critical for boots and it should supercede any minor performance difference between comparable boots. Don’t fall in love with a boot based on its specs or looks; buy the boot that best fits your particular foot.

For my foot, the Alien RS is probably the best fitting of any of the lightweight boots I’ve used. I attribute a lot of this to the excellent Scarpa/Intuition liner. (For reference I’ve ultimately added an Intuition liner to most of the ultralight boots I’ve used to get the comfort and performance I want.)

One thing that should also be said about Scarpa boots is that the shell size break is different than most (all?) other boot makers. For example, 27.5 & 28 are the same shell size in a Scarpa, whereas 28 & 28.5 are the same shell size in other companies boots.

I’ve generally bumped up to the 28/28.5 in most of the light touring boots I’ve tested, despite being a consistent 27.5 in pretty much every alpine boot and mid-weight touring boot I’ve ever skied. With the Alien RS, I was able to stick with the 27.5/28 shell without modification.

That said, the Alien is a pretty low-volume fit compared to other Scarpa boots I’ve used, including the new 17/18 Scarpa Maestrale RS, and the version of the Scarpa F1 Evo I had for testing. The good part about this (at least for me) is that the heel and ankle have the best feel and retention for my relatively low-volume ankle of any Scarpa boot I’ve used. Again, this may be in part due to the liner and the BOA, but my heel stays put better in the Alien RS than it does in the Maestrale RS (which also has an excellent Intuition liner).

The less fortunate side of the Alien RS fit (for some) is that the toe box is a little more cramped than the other Scarpa boots mentioned above. That said, I am happily skiing the Alien RS without any shell modifications, but needed substantial work at the toe box in other touring boots (like the Salomon MTN Lab) and many alpine boots.

The aspect of the Alien RS fit that pleased me most was the very adaptable instep height. Because there’s no plastic shell over the instep, instep pressure and height are dictated entirely by the moldable liner and highly adjustable Boa system. I have a high instep, and found the Alien RS to be supremely comfortable in this regard, whereas I’ve had issues with my instep in the vast majority of all alpine and touring boots I’ve used.

Ski Width Compatibility

Scarpa’s site currently states that the Alien RS is compatible with skis with a max width underfoot of 85 mm and a max ski + binding weight of 1300 grams. This seemed a bit unusual, so we reached out to Scarpa for clarification, and they told us that these recommendations are meant to “help customers pick the appropriate ski / binding systems for the specific boots they are using and to help reduce incompatible systems, boot and ski breakage, and warranty issues.” Scarpa said that using a ski / binding system outside the recommended parameters does not automatically void the warranty (they address every warranty claim on a case-by-case basis that takes into account many factors, including, but not limited to, what skis and bindings were used).

Bottom Line, For Now

The Scarpa Alien RS is an intriguing boot, and if it skis and tours as well as the other boots we’ve reviewed in this class, it could represent a nice step forward in the weight-to-performance ratio in this category of lightweight touring boots.

We’ve just started logging days on the Alien RS in the Alaskan backcountry, and will be posting a Flash Review soon.

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