Born out of requests from Salomon athletes for a shoe that would combine the proprioception of an S Lab Sense with the technical terrain capabilities of the S Lab X Alp Carbon GTX, the Salomon designers have created an outstanding hybrid shoe that is likely to find much more use than just off-piste mountain exploration.
A couple of years ago Salomon, working with Kilian Jornet and other Salomon athletes, developed a “fast and light” alpine shoe with very high mountaineering technical terrain performance- the S Lab X Alp Carbon GTX shoe. This shoe is lightweight for the category (500 gms size US9), has a Gore Tex upper/gaiter, a unique “carbon edging chassis”, accepts crampons for glacier traverses, and is suitable for lower level alpine climbs- in short a very versatile shoe for playing in places like the high Alps and other such terrain. This shoe, however, is not intended for running nor would running in it be the least bit pleasant primarily due to the stiffness.
Continuing development and testing with athletes that wanted to run (not hike or trek) in places like the high Alps and not be deterred by glacier crossings, Class 3 scrambles, or knife-edge ridge ascents that may be a part of a desired route, the S Lab XA Alpine shoe emerged from the prototype studio in Annecy. This shoe represents a hybrid design from a mash-up of technologies from the S Lab Sense mountain running shoe platform with the S Lab X Alp Carbon mountaineering shoe platform.
Starting with the super responsive S Lab Sense running shoe as a basis, a slightly increased drop (from the 4mm of the Sense to 6mm here) is used to increase mid-foot support and a modified “carbon edging chassis” is added to give lateral edge stiffness for scrambling and to allow crampon use whilst still retaining substantial longitudinal flexibility for running comfort. For protection in snow and ice, limited water resistance, and to prevent intrusion of debris inside the shoe, a full-wrap gaiter is employed that includes a water resistant lower half, a highly breathable upper half, and (what appears to be but is not) a waterproof zipper as well as ankle pads and a padded cuff at the upper termination of the gaiter. There is also a thick rubber toe cap for rock protection.
Inside, the foot cavity consists of what appears to be a S Lab Sense upper and footbed- and it definitely feels like the Sense as all of the fit technologies are present (EndoFit, SensiFit, Speed Laces and lace pocket, etc.). Due to constraints from the gaiter structure the shoe is slightly more difficult to get one’s foot into, however, once in, the feel is very much that of an S Lab Sense.
This construction of an S Lab Sense upper combined with the lightweight gaiter is grafted onto a deeply lugged outsole that utilizes Salomon’s latest “Premium Wet Traction” ContraGrip rubber compound. The lugs are highly separated to help facilitate responsiveness, grip, and to allow for more efficient mud and snow release.
The outsole also has a specially stiff section in the medial toe area to help with footholds on more difficult scrambles and to allow for secure insertion into snow. Salomon calls this the “climbing zone” and they actually label it on the outsole.
When you put this shoe on it definitely feels like a S Lab Sense, that is until you start walking around- this is when you immediately realize that there is a much stiffer outsole and chassis underfoot. It is not a “bad” feeling, just different- and different for good reasons:
Where most of us would not take the Sense across any potentially dangerous snow field, glacier, or up a challenging and consequential scramble, the XA Alpine will perform quite well and provide the confidence one needs to proceed safely.
While the chassis stiffness is important for mountain performance, it is not a drastically different feel and one that you will likely get used to quickly, as I did.
One initial issue that I have had is that the gaiter causes rubbing on the top of my middle toes near the foot proper. This was very noticeable on the first run but has become less and less noticeable as I use the shoes. It would seem that the gaiter is “wearing in” as the water resistant layer flexes and forms to the topology of my foot. I also wear super-thin S Lab Sense socks that give no padding whatsoever so wearing a thicker sock might make this rubbing entirely absent.
These US 7.5 (40 2/3 EU) weigh in at 334 gms (11.8 oz). Although heavier than a 7.5 US S Lab Sense Softground (247 gms (8.7 oz)) and noticeable whilst running, the additional mountain performance more than offsets the additional weight. And remember is was not so long ago that a 350 gm trail running shoe was considered a “lightweight racer”!
Initial Running impressions
I have had this shoe out for about a total of 50km of buffed and rocky trail running, off-piste scrambling, snow field crossing (thanks to some snow above 9,000 feet), icy steep trails, and some hill bounding intervals in muddy, wet conditions.
The buffed trail running is definitely compromised from a trail feel and speed perspective (compared to usual running in the X-Series, Sonic, and Wings 8) as the stiff nature of the shoe leans more toward a structured product. However, there is still a reasonable amount of trail feel that allows for pleasant running, although I would not exclusively run in these shoes. On mountain exploration runs where there is significant off piste terrain and possible snow these will be a go-to shoe going forward.
The performance is excellent on rocky and more technical trail terrain, dry or wet and is outstanding on off-piste scree, rocky steep ridges, boulder fields, and snow fields, once again dry or wet. The “Premium Wet Traction” ContraGrip really is much better than the standard composition in any wet and slippery conditions. Traction on submersed rocks at stream crossings is as good as anything that I have experienced. One note: drainage of the shoe is limited by the water resistant lower half of the gaiter. I found however that water is “pumped” out as you run.
I have had limited experience with the shoe on ice at this point but, so far, I have been astounded as to how grippy they have been- I have both ascended and descended some steep trails that have become icy with what feels like solid grip. They will eventually let go but since they accept crampons** I would suggest that anyone wanting to cross significant ice (or glaciers) might want to consider using crampons. It is not obvious why this compound would be so superior to the standard ContraGrip but there are basically three ways to get better grip in wet conditions and on ice- increased surface area, low-Tg rubber, and nano-sized particulates with sharp asperities. Based on a brief perusal of the recent patent literature all of the approaches are used by various manufacturers singularly or in combination. However, if one is to believe the data in some patents, it seems that the nano-sized sharp particulates are the key to increased grip in wet and icy conditions. I am not sure if the “Premium Wet Grip” ContraGrip outsole has the particulates though. But if it does, the grip should last if the compound has a uniform distribution of the particles throughout the thickness. If it is a surface layer only then there might be some decrease in performance with wear. Only time will tell.
I have had good performance in mud- both sandy aggregate and clay types with good grip and mud release. Much superior to the Sense. A couple of Class 3 scrambles have gone well including one that has been a bit edgy on past ascents/descents using the Sense- much more secure and confident with the XA Alpine.
If you want to see what the XA Alpine can really do on the feet of someone who knows what they are doing, then read Kilian’s post about the 7 summits of Romsdal where he tackles a difficult 24 hour traverse across the mountains in that part of Norway. He does these ascents (and, more importantly, descents) with nothing other than the XA Alpine and a prototype super lightweight ice axe. It is a great read and the video below shows some of the terrain.
For winter running on packed powder these shoes will be fine without any additional traction devices, but on ice I always go with carbide studs of some sort- either imbedded as in the SnowCross and SpikeCross or with an added and removable “mini crampon”, of which there are many varieties that will work well with the XA Alpine shoe. According to Salomon the XA Alpine is compatible with some “real” crampon models but they do not say which ones**. This is a good thing because it will allow for pursuit of mountain adventures that include significant ice.
$250 US. A bit on the pricey side but this is a unique shoe with a lot of technology and sophisticated design elements that are enabling for the new sport of “Alpinrunning“. There are, to my knowledge, no existing competitor products in this category. Based on functionality alone I find the shoe to be a good value if you are serious about getting out into (and back from) the areas you have always pointed at and said “We should go over there and bag those peaks.”
A high performance hybrid mountaineering-running shoe capable of going “fast and light” through highly varied terrain from buffed trail to Class 3 scramble ascents/descents to snow fields- and, apparently, with an ice axe in the hands of an experienced user, across real ice terrain. This shoe is the first true “Alpinrunning”-specific product and it is highly recommended for those that want to do some challenging mountain adventuring.
I intend to use these shoes throughout the winter for limited running, for the to-and-fro to skiing, and hopefully for some mountain adventures. I will post updates.
** Update 13 Nov 2016: I came across another recent review of the XA Alpine where an experienced mountain runner/explorer and shoe reviewer has essentially the same experience that I have had with the shoe. Additionally, this reviewer has tried out numerous crampon options and found many of these to integrate nicely with the XA Alpine. This further confirms the fact that this shoe will be a go-to high alpine running/exploring option for anyone comfortable in that terrain. See the review here: