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
However, it's also not super reliable in the field. I have broken the boa system a couple times, and while this isn't a deal breaker, it can be annoying to ski and hike with a loose lower, and it is a big pain to put a new cable in. The bolt that goes through the lever is a bit too short and the nylon on the lock nut doesn't quite engage the threads. I've lost the bolt while touring and almost lost it a couple other times when I realized the nut was going. Skiing out without being able to lock the upper boot can be quite grim. Finally, I've had the gaiter start separating near the cuff after only one season. I'm not sure how I'm going to fix that.
As others have mentioned: these boots are narrow and punching them would void the warranty. They are also a bit small and I would size up.
1. Does this boot ski as stiff as 1.0? If not as stiff, is that in a good way (like smoother flex closer to TLT6 vs the stiff brick wall of the 1.0?) or is it just flimsy like the original plastic alien?
2. The 1.0 has a fixed cord that you adjust by re-tying the knot and this boot looks like it has a cam to adjust more easily. When I have climbed vert ice with my 1.0, it seemed to work really well unbuckled but I wonder if the on-the-fly cuff adjustability of this boot would be a benefit climbing ice to get a little more cuff support and decrease calf fatigue?
3. Since this boot seems to have a more conventional liner, do people feel like it walks as well as the 1.0 or does the liner inhibit range of motion somewhat?
4. Lots of comments about durability. . any comment from Scarpa about changes or improvements next season?
1. Scarpa rates them 95 RS and 100 for the 1.0. But they are very different boots, the 1.0 is a Race boot with a stiff carbon cuff. The RS has been much refined from the original Alien to a race light touring boot. Forward flex is not flimsy and is considered by many to have the best downhill performance for a boot this light.
2. The cam is a nice touch, but still recommend tying a knot.
3. Range of motion is still excellent in the RS. New liner does not seem to restrict.
4. No announced changes next year, just adding a size 31.
The lean lock/locking lever screw keeps falling out. I lost one touring and one simply on the approach (hiking with the boots on my pack). I know this is a well documented problem but didn't see a solution mentioned after a quick scan through all the comments. I've about had it--and Scarpa customer service hasn't helped out by sending new screws despite several emails to them. I imagine you guys have a good work-around? Do you just recommend a screw from the hardware store with a locking nut? Any better suggestions? I almost thought I'd just put a ten-penny nail through it and bend it over but there has to be a better-engineered solution. Thanks.
- Boa cable broke. Replaced with a free kit from Boa under warranty, but doing that job is a major PITA. Not something that could likely be done out in the field.
- Ski/Walk lever attachment screw fell out while on a tour. I cobbled together a fix with bits from my repair kit to get home, and then replaced the bolt with the closest approximation from a hardware store once home, but Scarpa used a weird diameter bolt for this, and the replacement is slightly more narrow which leaves a fair amount of slop in the lever pivot.
- Cuff cord broke clean through on a long tour yesterday, rendering the ski/walk mechanism and cuff closure useless. I made an emergency fix with a Voile strap to hold the cuff closed and permit me to ski downhill (sloppily), but now I have to figure out how to replace that darn cord. This also revealed another weakness in the ski/walk lever's design: there is nothing that actually locks the lever into ski mode; there's just a groove in the lever that a metal tab on the boot heel slots into. The two are held together solely by friction from the pivot/attachment bolt. But, if the ski/walk lever is worn around the bolt where it pivots, or that bolt had to be replaced with a slightly sloppier fitting one as in my case, the lever has little friction to hold it in place and can simply fall out of lock mode, which it did about 100 times to me yesterday.
A few notes about fit:
- It is a narrow and low-volume last, unlike other Scarpa boots such as the Maestrale, which is great for me since my feet are shaped liked toothpicks, but people who have normal feet might need some modifications to fit comfortably.
- Sizing runs small. I'm a 27.5 in alpine boots, 28.5 in all other touring boots, and a 29.5 in the Alien RS, which is borderline too small. If I keep these I will get a punch in the toe box to make more room.
- As others have noted, the toe box is oddly shaped and aggressively rounded off. This causes even narrow feet like mine to feel jammed into the sides of the toe box.
- Forward lean is minimal and forces a more upright stance.
If it was more reliable it would be a great option for me, but for now I'm shopping for something that won't break as often, even if it ends up being heavier.
I had the pleasure of using this boot for three days before the cuff broke right above the ankle pivot on the outside of the left boot. The boots were amazing, but broke just from flexing forward skiing normal conditions. I attempted to warranty them and Scarpa denied the claim saying I “Overflexed” the boot. Total BS. I continued to baby them in SkiMo races and just found out the other boot broke in the same place. Such BS.
I don’t understand how people can ride these things and not break them. I’m only 150lbs and I broke both boots just by skiing groomers. (Probably because I’m so freakin fast!). Super pissed at Scarpa for not warrantying them. Can’t say I would recommend them to people.
I have this boot for almost two seasons. Both my Boa cables broke at the end of last season. The first one i got replaced for free by Scarpa, and the second I did myself with a replacement kit... fairly easy. The wire they put in the stock RS is surrounded by a black plastic, and probably a bit thinner... so it is fragile compared to the typical Boa cable (So they told me at the Boulder Scarpa Repair Facility). By replacing it with a Boa cable without the outer plastic, the Boa tends to break less. I haven't had any problems this season, and I think Scarpa hasn't had people complaining about the new wires they replace the stock one with.
I will add that a Boa mechanism is relatively complex compared to other tightening options out there, hence you can expect something more fragile. But it is easy to replace with a simple kit, and the comfort of the adjustable tightness is amazing. In my opinion, this boot is worth it.
Hope that helps.
"We have updated the boa to a metal cable instead of the plastic coated as it is much more durable. The repair we do requires a rivet press, as we replace all of the clips as well. I can send you the parts, but the better fix is to send it in to us. On a rush repair we can have it done in a few days once we receive it."
I am not sure why Scarpa feels the need to replace the clips. Maybe the clips have a tighter radius of curvature and would kink less?....just guessing. I'll see how the repair holds and maybe send boots in at the end of the season for clip replacement, if it still seems appropriate.
Fastest transitions ever. While I'm still not racing material by any means, these boots are so quick and easy to transition. All you have is the single ski/walk throw on the back of the boot. If you needed, you can quickly tweak your forefoot pressure using the boa but generally you can set it and forget it.
Excellent booting tread + expansive walk mode. These are so comfortable to hike/walk/scramble in! I think this is mostly due to the wide walk mode. I almost feel like I can walk normally and this has come in handy when doing multi-mile dirt approaches with skis. The boot part fits snugly, more shoe like, and this means fewer blisters as well. The foot fit is also amazing enough that I have ice climbed in this boot with fantastic results. I felt super confident and didn't have any toe or shin bang. Plus they are basically as light as a beefy mountaineering boot!
Awesome gaiter - the gaiter on this boot is so much better than the Salomon gaiter. It fits super snugly around the liner and doesn't move unless you really want it to. Seals out snow, I've never had damp feet.
Love it and hoping to ski it for many seasons to come!
The question I have concerns the forward lean. I know others have asked similar questions, and I actually just emailed Skimo.co directly, but I thought I would post here as well. I am very used to the 16 degree lean that the Spitfires have, and has very surprised that Scarpa decided to only go to 13 degrees (especially when the LS Sytron goes to 22 degrees!!). I put a shim in the back but am still feeling a bit off-balance when I try to drive turns or do techy jump-turns.
I am thinking that the answer might lie in the walk/ski mode heel lever. Looking at photos, it appears that the Alien 1.0 has a slightly different lever, and I am wondering if anyone knows if it happens to be longer than the Alien RS one--I think a few millimeters would make all the difference regarding lean. Any other ideas regarding ways to increase lean are welcome. I am otherwise pretty smitten with the boot.
I measure a 26 in length and was fit into a 27 boot. After about 6 days the boots have become quite sloppy in fit. What liner would you reccomend to take up more space than the stock?
I've been using TLT6 first edition in size 27.0. My big toes gets pretty damn hurted on long days because of the boot lenght which is too small so i would fit better with 27.5 tlt6. They still works great while strictly ascending.
Which size do you think would fit best for me? 27.0 or 28.0? I ski a lot of long days on flat mark before reaching the mountains, so i hate when my toes hit the front wall of boots.
It was an emotion-driven purchase. My beloved LS Syborgs all of a sudden turned into torture device when some kind of bony protrusion grew on my foot and it gotten really painful after only a few hours of touring, especially when in a ski mode. I went to the ski shop to try to do something about, saw Alien RS, put them on and pulled out my cc!
It's been a little tight at the forefoot first few outings but then it went away and now the boots are really comfy! I had the liners molded but frankly I think the fit improved just from usage. Anyway: my feet are old, medium width, pretty wide at the toes but these boots fit great! I probably went with 1/2 to 1 size too large so the fit is not "performance fit" but they ski great for me and very comfortable. No hot spots, no blisters, nothing! Maybe I should try a foot-bed to take up some of the slop but maybe it's like trying to fix what's not broken?
A few other things: crampon fit with my crampons that I assembled for Syborgs from several different parts is awesome! BOA adjustment is fantastic, super easy to tighten and you just pull the knob and it loosens. The gaitors have no zippers to break. Liners seem thicker and way warmer compared to Syborgs. It's really easy to put the boots on which is kind of nice when you are on a multi-day tour! I'm in love with these boots but let me point to a few negatives:
Ski/walk mechanism is way harder to work compared to Syborgs. You need to bend back to reach the lever and it may take a little fiddling. Really no big deal and I'll probably learn to do it quicker with time.
As others pointed out, the cord for tightening gets frayed pretty early and the cord slips through the locking fitting when tightened hard. A knot on a cord would probably solve the slippage problem.
I'll add other negatives if I could think of anything else.
Cons: Durability of gaiter pulls-ripped off pretty early while sliding a liner in. Cord that also serves to put the boot in ski mode also visibly is frayed after about 50 days and also slips through the cam lock. Like others I have just tied a knot so that it will not slip through. I have also found the single throw latch to loosen over time, requiring occasional tightening. I am also concerned about the stress on the small cam lock from the added knot, though I havent noticed any issues yet. I also do not like that the sole is very flat. Comparatively to some other brands, there is almost no rocker, so even though ankle ROM is huge, the "naturalness" of the walk is impeded by the flatness of the sole (though that may be preference). I also question the use of the carbon infused grilamid throughout the entire shell, I will explain in the fit notes.
Fit notes: very narrow toe, not anatomical shape. symmetrical rounded pointy ish toe (never seen anyone who has feet or toes that look like the toe box on this) Fairly low volume. My foot measures a 27 but I have to do a 28 in this and its still too tight for my width. The heel and midfoot are wider. I personally have a wide forefoot and narrow heel. This boot is too tight in the toes and too sloppy in the heels for me. I had to add a lot of foam in order to get good heel hold on this, I also had to add a foam shim to the shin area to held with heel hold. Because of the very specific fit of the boot, it is even more limited because of the carbon fiber infused grilamid. This material is stiff, but is extremely difficult to punch. And Scarpa doesnt approve of punching it (voids warranty I believe). I have had mine punched but compared to normal grilamid I was much more limited in how much I could punch it. So if your normal practice is to downsize shell and punch it out, or have a suboptimal fit and modify it, the potential for modification is very small. Even after punching I didnt have enough space in the big toe area so I used a razor to cut out a couple mm from the inside of the liner by my big toe. This boot should work for you if you have a narrow forefoot and in general low volume feet. Talk to the guys on this site, they will steer you in the right direction as far as fit. If you have average, wider "american" feet, my guess is these will be a tough fit out of the box and may not work.
Notes to Scarpa: You know what most people's feet look like, as evidenced by the Maestrale, and other mountain boots, like the Mt. Blanc or the new Ribelle or various other boots. Why do you change the last for "race" boots? Not all people who like to race suddenly morph the shape of their feet. Also, if you are going to make a very specific type of fit that doesnt work for a lot of people, at least make the lower part of the shell out of an easily modifiable material like normal grilamid so that those of us that dont have small elvish pointy toes can have a solution for fit.
Ultimately I will keep the boot, unless someone wants it, but I cannot bare it for multi-day or very heavy mileage days. But if I want high performance skiing or dont plan on a super long day I may take them, but usually comfort wins out for me, so these may be collecting dust for me now. Still an excellent option if it fits you, definitely try in store before purchase.
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