Every so often a company will debut a category-shattering display of engineering that seems to break all kinds of rules, defy stereotypes, and spearhead a different generation of skiing. This ain't your grandpa's ski-day! Behold: the Alien RS. Holding true to the da Vinci mantra that "simplicity is the ultimate sophistication," the Alien RS is a delightfully simple boot. A stiff carbon-infused Grilamid cuff is mated to a stiff carbon-infused Grilamid lower by way of an unbelievably dexterous pivot that again, defies stereotypes. A Boa closure on the lower shell wraps around your foot to create a secure and precise fit. Racers, say hello to your everyday boot light enough to sneak in 40,000ft of dawn patrols per week; freeriders, mountaineers, and steep skiers, say hello to your beefy race boot capable of taking you further than ever before.
- Carbon Grilamid LFT Shell and Cuff blend industry-leading power-to-weight ratio with industry-leading price.
- Lower Shell is built around a 3D Lambda Torsion Frame to increase lateral stability and power transfer.
- Speed Cam Lock ski/walk mechanism is reliable, durable, and precise.
- A waterproof, zippered gaiter tempts snow to even try to get into this boot.
- Offset toe lugs promote a more natural walking motion to increase touring efficiency.
|Weight (pair)||1840g 
||1 + BOA, Single Throw Speed Cam Lock|
||7°, 9°, 11°, 13°|
||Carbon Grilamid LFT|
||Intuition Cross Fit Tour|
||Vibram UFO RS|
|Skimo Co Says|
|Usage||Speed touring, high performance ski mountaineering, exceeding expectations|
|Notes||Grilamid infused with long strands of carbon fiber increase torsional stability and precision. A zippered, waterproof gaiter invites you to use your imagination when accessing lines|
|Bottom Line||If the Holy Grail was a ski boot|
|Compare to other Race Boots|
Questions & Reviews
The Scarpa Alien RS is a very lightweight "race plus" touring boot that is best paired with lighter and narrower skis. It is not designed to work with an MNC style binding like the Salomon Shift 13, and is unfortunately not compatible.
My current touring boot quiver is these guys and a Maestrale RS, which I think pretty well covers all the ground - Maestrales for more aggressive skiing and Alien RS for the big days.
The walk mode on these is not even comparable to the Maestrale its so good. I've had a pair of F1s in the past, and it's also significantly better than them. I used to mess around with my risers all the time, but with the RSs I just switch to the middle riser and the ROM is good enough that I never have to change (even for a long sustained flat).
On the down, these are definitely nowhere close to skiing as well as the Maestrale, but they are just about stiff enough. In good snow they're totally fine (I've used them on pow days with a 108 underfoot ski and felt very happy jumping off of ~5 footers) but I don't feel comfortable jumping off anything bigger in these, and I they definitely don't drive a ski the same way when the snow gets funky. That being said, these are pretty much the perfect boot for long days to ski big lines. Jump turns in 50+ degree couloirs don't feel any different to me than in my Maestrales - I just have to remember not to cruise out the apron at the end!
I have skinny calves so I have to have the dyneema cord quite tight, which makes locking the boot into ski mode take a decent amount of effort. The cord would not lock in place until I tied a knot in it (at which point the camming mechanism might as well not exist). But now that it has the knot in it, it doesn't slip at all, which I think will greatly increase the life of the cord (it seems bomber to me, so I can't see how anything other than abrasion would cause it to snap).
Pros: Truly as light and frictionless as advertised. The RS is wicked fast to transition from skiing to touring. I don't come from a skimo background, moreso a freeride skier, and so obviously was curious/skeptical of my ability to drive these on more aggressive lines and slightly wider skis. While Scarpa says not too (you'll void your warranty skiing skis above 85cm underfoot), I can easily use these boots to drive my Mythic 97's (184cm, ~1400 grams) through all sorts of snow at various levels of aggressive skiing. The lateral stiffness is enough to put skis of that size on edge without losing confidence. But they are better paired with a light ski mountaineering ski, for me th K2 Wayback 80 (170 cm, ~1090 grams). While the dynema tightening system looks uninspiring, it works. Obviously touring in them is a dream, as is booting and cramponing. The soles (like most scarpa boots) are a fantastic vibram that makes rock scrambling or roped missions in them much less scary. ROM is greater than my abused ankles so I can't even really find their limit. I am a wide-footer with a high arch, and these boots are the best fitting boots I've ever worn, good for Hobbits like myself. The BOA system is simple and effective, and has held up durability wise for me thus far.
Cons: Durability concerns that other have noted are real. After one full season (~80 days in them) the gaiter has come unattached from its connection to the lower boot near the ankle. This isn't a huge deal, as some Tenacious tape and a bit of superglue is enough to repair it sufficiently. Purchase some extra dynema of the right width for both boots and carry it with you in your pack, just in case--I haven't had mine snap or even fray yet, but others have. The sole is also chipping off in small bits and pieces near the edges, but a below average snow year in western MT left some exposed rock for much of the year so I can't blame them too much there. These boots also take some dialing in, both in terms of skiing and fit. As to the skiing, they require a more engaged, balanced and boxer-like stance to ski them right I found. They have an obvious wall of stiffness in the front of the boot when engaging forward--keeping pressure on this wall (but not too much due to its less-than-progressive nature) take time to understand, but you'll get it. This balance is key to effective power transfers and also not getting thrown into the backseat, where you will feel the limitations of the boot. This boot asks you to float like a butterfly and sting like a bee. I did attach an additional booster strap (from Skimo Strap here in MT) to gain a bit of forward stiffness and slight increase in progressivity. I find this has enhanced the boot performance to be worth the extra 30 grams, but it does slow down transition times a hair. The camming mechanism for the dynema tightening system can also be a bit slippery, but simply find the right length of cord for your preferred tightness and then throw some knots behind it the cam.
This boot rocks. If SkimoCo still has this boot in stock while you're reading this review, get them, especially if you can find a good price due to their discontinued status.
Question: what should I use for a replacement liner? I love the original Scarpa liner but it can't last forever and the Scarpa replacement liner is unavailable. What's the closest? Thanks.
Performance - They are plenty stiff, yes they don't have a very progressive flex but I quickly got used to them and isn't a thought anymore. Skiing powder is not a problem for my daily 100mm ski. And to the chagrin of Scarpa, I can drive my bigger powder ski.
Walk mode- no need to discuss, they are awesome. Hiking is so much less a chore. The ski/walk mode is excellent as is, hate to see it go. I can easily flip open and close with my ski pole. No bending over and messing with buckles and powerstraps. The cord slipping doesn't seem to be an issue for me and I do have it knotted. If you are one who really cranks buckles and power straps, you may not like, but for me, no problem
Durability-zero problems to date. I believe if properly fitted, and I have custom footbeds, you do not need to tighten the BOA much. For the majority of people, the BOA hasn't been an issue. Same with the cord, I don't overtighten and I don't even have any fraying yet. There does seem to be some wear points between the shell and liner. I have been trying to use the patches on the shell and tape to keep ahead of it.
From powder to suncupped summer snow I couldn't expect more from these. And seriously thinking of getting another pair before they become the LT
Had to tie a knot on the dyneema cord, the stopping mechanism kept losing tension.
A few notes:
- Cord closure requires a stopper knot to prevent slipping which makes it difficult to dial in the tension or adjust throughout the day. The knot wears down one section and will probably break the cord eventually, but it looks easy to replace.
- Fit is much narrower than other Scarpa boots. All other Scarpa boots I have tried are way too wide for me but these fit well.
- Booster strap can be installed by drilling a hole in the back of the cuff. This helps the downhill performance a bit. I haven't broken the cuff yet, fingers crossed.
I will attempt to address few of the concerns many people seem to have about this boot. First, “it isn’t going to be warm enough on cold winter days”. In my experience, this boot is adequately warm for most very cold days (single digits F) especially when you are moving fast, and this boot should inspire you to do so. Second, “this boot isn’t going to be durable or reliable”. This boot is like many other ultra-light pieces of gear, I wouldn’t advise wailing on it. I did break my right cuff about an inch above the pivot while skiing one day, luckily Scarpa replaced the cuff for me in a (somewhat) timely fashion.
The Alien RS will become an absolute cult classic of a ski boot. Much like the TLT-6. Its performance greatly outweighs its mass, and I think that is the idea with most of the gear on this site. Get yourself a pair before they are gone. -Scarpa is canning the Alien RS for next season… :(
(Full disclosure: I did not but these boots from skimo.co but I really like this site and I think this is a great place to post and read reviews.)
Earn store credit by writing reviews. Learn more.