SCARPA Alien RS Boot

Hands down the best skiing boot I have ever used in this weight category. I use them with Voile Objectives and Helio 95's and they drive both skis very well. So light! And so easy to use. I think they're total game changers. Over the past 2 seasons I have put approximately 80 days on my Alien RS's and they are holding up surprisingly well. I have yet to have anything break or really fail. I do carry replacement / backup Dyneema cord but am still going strong on the originals. I also keep an eye on the walk/ski mode bolt and put some blue loctite on it for piece of mind. I expect to get another season or two out of them for sure!

Hi, I wanted to know if this boot is compatible with Salomon/Atomic Shift bindings?

Is there a woman version of the Scarpa Alien RS Boot?

I skimmed through and saw lots of comparisons to other boots, but not to Alien 1.0. . . maybe I missed it.

So questions:

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?

Hi Skimo folks,

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.

After a year of using these boots on a variety of trips from multi-day tours to quick uphill training skins at resorts, I have some observations. Overall, this boot is a good option for race training and lightweight shorter trips if you have a narrow-ish foot, and it skis extremely well for how light it is, but I can't recommend it as a daily driver or for longer tours in rugged terrain. It's simply not reliable enough. These are the failures I've experienced so far:

- 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.

The finest lightweight touring boot of all time. I have probably 200 days and 700,000+ vert on mine and they're still holding strong! I've skied tlt5s, 6s, backlands, f1s and several others, and really nothing comes close to the worry-free efficiency of the RS. The one caveat is that you really have to know how to ski for them to work. With a solid technical foundation and an understanding of the limitations of 1 kilo boots, they will take you anywhere. I ski them on 80mm mountaineering skis, all the way up to 110mm powder skis, and they've never complained once. They're the warmest, most comfortable boot i've ever had and when they die (they're close), i'll get another pair.

BROKE ALMOST IMMEDIATELY,
NO WARRANTY!

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.

Hey my Boa cable just broke as I was on the uphill. I’ve had maybe 10-12 outings on them. I’ve loved them till now. Aargh. Has this been an issue? Fixable, I am hoping? (Alien RS)

My favorite touring boot to date! My boot journey has been a bit like Goldilocks...but I'm so glad I found these. I started skiing the Dynafit Px One which is a pretty heavy touring boot. From there, I swung back to the Salomon Slab boots which I found overly complicated and frustrating to use. Finally, I landed on these and I LOVE them.

Awesome points:

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!

I just purchased this boot after skiing the original LS Spitfire for sixish seasons. I have skied the boot twice and like it so far. I do think it is a little on the chilly side (at least for Rocky Mountain National Park), but the skinning/climbing performance is great. It is also quite stiff and almost skis as well as my Spitfires.

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.

Hi SkimoCo,

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?

Thanks!

fit relative to the older all yellow Alien? I was sort of between a 26 and 27 in those boots. big foot measures 272mm. low volume and a true D width.

Hi!
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.

Eric

Just wanted to add a few observations regarding the fit of these boots. Enough was said about ski performance and I'm not a ski expert to add much on this subject.
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.

Pros: Light-very stiff for weight. walk range is great, similar to other race style boots. Boa is great for easy adjustments. Love the simplistic single throw for switching to ski mode. Tread is very durable. I have only skied race style boots, I've never skied an alpine boot, but comparatively this is the stiffest boot i've used. I have no problem on 100mm waist skis with this. Wouldnt hesitate to use on 105s, but I am a balance skier, I dont drive from the cuff.

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.

Is there a cuff cant on this boot? Thinking no, but somewhere I thought I read a review that mentioned a cuff cant.

Got these at the beginning of the season and have pushed them hard, what an amazing upgrade from my old TLT 5 Ps. Scarpa seems to advertise this as a race boot, but I don't think this is the case, not quite light enough, the ankle articulation isn't quite there, and there is much too much resistance pushing the boot through the articulation for it to be called a true race boot. I think skimo.co makes a good distinction by calling this category "race-plus." Boy for the weight does this boot ski, easily equal to my old TLTs, in my opinion everyone between freeride shredders and racers should be zipping around on these.

Sizing is tighter and narrower than most Scarpa boots, I'm commonly a 27-27.5, I chose a 27 in these, they fit quite nicely but it's definitely a performance fit.

Gaiter is amzingly thought out, and I love that they added a clip for binding tethers. My only complaint is that the cam device used to adjust tightness of the upper eats at the dyneema cable, hasn't failed yet, but is visually core shot. A thought as to how Scarpa could make these better is by using a full carbon upper, retaining the carbon grilamid lower and lining it with weave as in the current 1.0, this would make the boot considerably stiffer and lighter without compromising durability of the lower for scrambling. Perhaps the new 1.0 will fill the ticket.

These Alien RS boots ski astonishingly well for as light as they are. The innovative Boa and upper cuff tightening systems provide for something that feels a bit like a four buckle design in a 2 lb boot. I have fifty days or so of skiing in these boots, and a couple days of ice climbing. No concerns or complaints about durability. Scarpa suggests that these boots are best for skis 85mm or less. I ski these on 84mm skis, but feel that they could comfortably power a bigger ski. A ski partner skis these boots on 95mm skis without complaints.

The boots are a little tight in the toe box, and fit a little bit short. I usually ski a 26.5 ("performance fit") boot, and my size 27 Alien RSs are barely big enough (I have a footbed in the boots to raise my arch and shorten my foot a bit).

Not an ideal boot for ice climbing. The offset toe welt does make the boot natural to walk in and tour in, but might require you to bend your crampons' toe bails to get a snug fit. The ski/walk mode arm interferes with the heel clip on most crampons, meaning you'll need to loosen your crampons to switch between walk/ski mode.

The boots are comfortable and dexterous enough that I have no difficulty driving my manual-transmission Subaru in the boots, and often find myself running errands in town on my way to/from skiing in the boots.

This is a perfect boot for ski mountaineering and any sort of long distance touring. If your objective is moving quickly and confidently on snow in the backcountry, I'd suggest that the Alien RS is a perfect boot.

Hi there. Was wondering if the Aliens RS can be punched. Of course Scarpa states against that and it would devoid the warranty. Currently skiing 27.5 Dynafit Beast with a small punch for my right foot bunion. Tried the Aliens RS in 28 and got a really good fit except a pressure point in the bunion. It might go with liner molding, but it did not in case of the Dynafits. I would probably need couple of millimeters punched, do you think its doable?
Thanx for advice Peter.