Salomon S Lab X-Series – Final Update

With over 750 miles (1200 km) of very comfortable trail running, I have now taken a first pair of the S Lab X-Series “road” shoes from box to bin. These miles have been almost exclusively in rocky and rocky technical trail situations including scree, scrambles, water crossings (including rivers), medium mud, snowfields, and precipitous knife-edges. The shoes are still very runnable but they have lost a bit of forefoot cushioning and, in an effort to be proactive about shoe wear-out rather than (regretfully) reactive to some sort of foot issue, I have taken this first pair off-line and started rotating two new pairs. I could continue running in these on shorter runs but I will probably use them for hiking through the summer. Suffice it to say that the X-Series has more than lived up to initial impressions and continues to be a great performer on just about any trail here in the Northern Rocky Mountains.


Salomon S Lab X-Series after 760 miles (1225 km) showing very little wear on the uppers and insoles.


These shoes have about 760 miles (1225 km) so at US$160/pair that gives a wear value of about US$0.21/mile (US$0.125/km). This is about the same calculated cost per mile as that experienced with the Sense 3 Ultra. 750+ miles (1200+ km) is very good wear in my experience even at the $160 price point.


The X-Series upper is constructed of three primary materials: a thin Lycra in the forefoot back to about the midfoot, a very thin mesh on the outside midfoot area, and a beefy nylon mesh for the remainder around the heel, etc. I initially had concerns about the durability of the Lycra and thin mesh materials, as Salomon in the past have used materials in the S Lab Sense line that did not wear well. Additionally, Salomon markets the X-Series as a “road” shoe with crossover capability to “City Trails” (whatever that means). The wear characteristics of this shoe in the rocky and rocky technical trails that I run was a concern as it relates to durability of the upper. Even after this significant mileage on rocky and rocky technical trails there is no sign of excessive wear (or wear at all) in any of the upper materials with the exception of the tips of the heel counter inside surface.


Image of the upper Lycra forefoot region showing no evidence of wear after 760 miles (1225 km). The Lycra material is clearly very durable in rocky trail use.


Similarly, the inside forefoot Lycra region also shows no wear.

The heel counter inside surface is the only place, other than the midsole cushioning, in the entire shoe that is showing any kind of wear-out. These wear-through spots do not affect the fit or function of the shoe at this point, but continued degradation will likely become bothersome.


The inside heel counter surface materials are starting to show wear and have developed holes.

The polymer-fabric overlays/lacing structure exhibit no wear and continue to perform as when new. The overlay fabric/ lacing structure materials are very tough as they experience a lot of strain and abrasion, yet, other than color fade, look new.

The “rocker” geometry has held up well and has, in fact, become more pronounced. I find that I very much like the “rocker” and suspect that this geometry may play a significant role in the high comfort level of the X-Series.


The Salomon S Lab X-Series “rocker” after 760 miles (1225 km). The “rocker” is a bit more pronounced after use.

Salomon X series compared to Sense 4

Compare the image above to the “out of the box” rocker of the X-Series and Sense 4 in this image.



After a few bouts with foot bruising I have committed to retiring a shoe before a worn-out EVA layer leads to some sort of acute or chronic foot issue. I have experienced both and solved the issue with shoe replacement. In the X-Series I am perhaps retiring this pair a bit sooner than I would have in the past, but I am trying to navigate a balance between wear-out and insufficient cushioning. I am erring on the more cushioning side of that balance going forward. A runner with a “tougher” foot might get another couple hundred miles out of these shoes.


Perhaps the most remarkable circumstance with the X-Series is how durable the outsole is. I am a significant supinator and therefore typically see excessive wear on the outside edge of the outsole, particularly at the heel (see my other reviews and updates of the S Lab Sense variants for examples of this type of wear). The X-Series shows almost no wear across the entire surface and clearly the outside heel area is not differentially worn relative to the rest of the outsole. It is hard to believe when looking over the outsole that these shoes have seen 760 miles (1225 km) of use on rocky and rocky technical trails, including scree, scrambles, and many water crossings.


The outsole of the Salomon S Lab X-Series after 760 miles (1225 km) showing very little wear and no preferential wear at the outside outsole edge and, particularly, the outside heel area. This is the first S Lab shoe that I have used that has been this durable given my substantial supination.


The Salomon S Lab X-Series is the most comfortable trail shoe I have ever used, and my use includes many of the Hoka, Innov8, and Altra offerings. I will note here that I also had initial concerns with how “hot” the X-Series would run as Lycra is well known for not being very breathable. Having run a few times in air temperatures exceeding 85 F (30 C) where surface temperatures were in excess of 100 F (38 C) I can report that the shoes actually run quite cool and certainly on par or better than the Sense. Also the proprioception of the X-Series is outstanding and leads to substantial confidence while running in technical and challenging terrain as well as increased speeds on descents.

How Salomon accomplished all of this with what is billed as a “road” or “hybrid” road/trail shoe I am not certain. I will offer that the combination of a larger outsole area, larger outsole contact area, the dual density EVA construction, (apparently) just enough additional midsole thickness, and light materials has resulted in a very different shoe than the S Lab Sense- one that not only performs in the mountains but also does so with a comfort level much greater than the Sense, particularly on long runs/races. It seems also that there may be some sort of midfoot construction detail that leads to a higher comfort level as one fatigues and begins to transition from a high proportion of forefoot strike to increasing amounts of midfoot and heel striking. All of this is conjecture but the proof is in the taste of the pudding…. and this is very good pudding!

Bottom Line

Salomon have (unexpectedly, since the X-Series is supposedly a “road”/”hybrid” shoe) produced a high performance, light-weight trail shoe that provides a high level of long run comfort, superior trail feel, high durability, and all-around performance on mountain terrain. This is a shoe that trail runners should consider even though Salomon bill it as a “road” or “hybrid” road/trail shoe. Highly recommended.

I will be using the S Lab X-Series exclusively for training and racing this season including two 100 km high mountain/large vert races, a four day mountain stage race (with obscene vert), and a high mountain 50 miler. Looking forward to where Salomon takes the X-Series for SS2016.

Note 12 July 2015

It seems that Kilian used the S Lab X-Series for some portion(s) of his 2015 record-breaking performance. Here he is changing shoes at Telluride aid station before climbing 1400 m (4500 feet) up Bear Creek on road, then trail, then snow fields over Oscar’s Pass and then a 950 m (3100 foot) decent into Chapman. Looks like he is changing into the X-Series (with an all black wear layer) from the 2016 Sense (or some new prototype). This is a testament to the versatility of the X-Series, a supposedly “hybrid” road/trail shoe!

Kilian Hardrock w_2016 shoes

Kilian changing shoes at the 2015 Hardrock 100 Telluride aid station before a difficult 1400 m (4500 foot) climb and 950 m (3100 foot) decent. Looks like he is changing into the 2016 X-Series from the 2016 Sense. Photo credit:





16 thoughts on “Salomon S Lab X-Series – Final Update

  1. I also confirm these are great easy trail shoes.

    On roads, the outsole has a tendency to pick up a ton of tiny gravel and sand pieces in the many small creases it exposes. I think this is why I found the shoe to be noisy on roads…after a couple of miles, you get the typical noise of that material scratching the pavement, instead of the subdued noise of rubber dampening the impact of contact.

    But on easy trails, this is not an issue at all because, obviously, trails are themselves made of that same material.

    • Hi Laurent,

      Glad to hear that the X-Series is working out for you… on trails anyway. I have not run much pavement in the X-Series (less than about a mile a day, so less than 100 miles total on pavement) but I also have not had any noticeable gravel stuck in the outsole crevasses. I have had this issue with the S Lab Sense from time to time.

      If you have not already, I will encourage you to give the X-Series a try on more difficult, technical, trail terrain. I find the shoes to be very good performers on such trails.

  2. Hi Robert,
    just a quick update. I did over 100km in them last month, one of the best I ever had. But just today same thing happened to me on easy trail running downhill as to You, that is small sharp stone had penetrated through midsole in area that is not covered by the ProFeel rock plate, and into the interior of the shoe. See image here, . While different placement than in Your incident, it seems something to have in mind when running in them. And maybe Salomon can invest in to additional 2 square cm of profeel plate in next version:-)
    In any case, keep up a good work, your reviews are definitely one of the best out there.

    • Hi Erik,

      Thanks for the info. It would appear that such small sharp rock penetration is an issue for the X-Series now that two of us have experienced it. I agree that this could be fixed with a more complete ProFeel film but this might compromise the flexibility of the shoe. I am sure there are design approaches that can solve this issue and I hope that Salomon do fix it as the X-Series is a great shoe.

      Thanks for the compliment on the reviews, there is a dearth of “box to bin” reviews and, to be honest, such “box to bin” reviews are really the only valuable ones. Initial impression reviews with less than a couple hundred miles of use are of very limited value, at least to me.

      Best of training to you!

  3. Hi Robert!
    I was glad to meet you at Standhope on saturday! I hope you had a great race, I ran behind you at the start and passed you after the first creek crossing without seeing you again. This race was just amazing, Loved it!!
    As I shared with you earlier this year, the Sense Ultra don’t offer enough cushion for me for event longer than 20 miles. However, I have found the BEST shoe for me for distances over 25 miles and this is the S-Lab Wings
    Are you planning on reviewing them ? For me,they are the best as far as cushion, toe protections, weight, grip. They are basically like the Sense Ultra but with more cushion
    I raced in them at Standhope and they excelled at this terrain.

    Thanks for this final update.I actually am wondering if Kilian ddidn’t switch for a prototype of S-Lab Wings 2016 ?
    Also, do you know which shoes Ricky is wearing ? I believe those are the same he ran Mt Marathon with ?


    • Hi Frederic,

      Nice to meet you as well- looks like you had a great race and posted a very good time for that challenging course! Yep, saw you go by at the start of the first climb and did not expect to see you again but I did see you well ahead at Fall Creek where I was still holding to an 8h pace when I promptly bonked and struggled to the finish…. still have not figured out fueling and could not get anything significant down after about 3 hours in- I have always had a weak stomach and one definitely must have an iron gut for Ultras! The only “good” thing is that I have recovered quickly as I was unable to push for the last 4 hours. Now on to the next race/learning opportunity!

      I have not tried the S Lab Wings yet. I ran the race in the S Lab X-Series and they worked well on this very mountainous course even with the scree/talus. I prefer a lower drop when fresh but the X-Series has demonstrated that an “in between” drop has advantages when one becomes fatigued, particularly in Ultras. The 8 mm drop and “rocker” geometry of the X-Series promotes a forefoot strike but also provides some heel support when fatigue sets in. I think this (and the slightly greater cushioning) is why the X-Series is so much more comfortable than the Sense Ultra 4, at least for me. Given the 9 mm drop, similar “rocker” geometry, and significantly greater cushioning of the S Lab Wings, they are something I need to put through some testing. The 270 gram weight is also palatable. I am about to put up a review of the Salomon ProPulse- their Hoka-like shoe that is a bit heavy but quite plush.

      Yes, Kilian may be switching to something other than the X-Series but the last really looks similar. However, it is not possible to be sure and he could be in something very different and maybe even some hybrid between the Sense and the Wings or some entirely new concept. I have not gotten a full report on what Salomon showed at the summer outdoor expos but the only thing that has come up is the S Lab Sonic- apparently the “Max King” shoe primarily intended for roads- it even has regular shoe laces!- bad decision and I hope they put speed laces in the box so one can switch them out. Here is a video of the Sonic Pro but you can see the S Lab Sonic to the presenter’s right:

      As far as the new “Kilian” shoe… well I have seen nothing yet so stay tuned! In the meantime I will be trying the S Lab Wings as you have suggested.

      Hope you have a good training cycle and a great next race!

  4. Yes, I had a great race and felt strong. The only disappointment is that I got lost at the top of the 2nd climb (the part they forgot to mark). I probably lost 10-15 mins which could have allowed me a sub 7h30min finish. But all things considered, I am supper happy with my result, especially since I have Wasatch 100 coming up next month.
    Im sad to hear you had stomach problems. I actually recall you mentioning it in your 2014 reviews where you were listing the improvement and areas to work on. I hope you can figure that out!
    I had initially considered the X-Series but the lack of real “sole grip” made me wait for the S-Lab Wings and boy oh boy i havent been disappointed so far. I bought them in France and first tested them in the alps where they excelled on steep screes, slippery trails……but what struck to me is that my feet never felt tired and beat up in 6+ hours runs (they do feel tired and beat up if I wear the Sense Ultra for more then 2-3 hours). I think you nailed it when mentioning the drop and the rocker geometry. It helps me after several hours, I need this type of support. I think only Kilian is able to run 20+ hours in the Sense (basically the shoes designed for him!)

    I’m sad to see that Salomon released a S-Lab without quicklace!!! Thats why I bought Salomon in the first place!!!!
    Also, as far as the new Kilian shoe, the only thing I know is that the Sense 5 will be out soon (not much changes it looks like ) :–1123.html

    Also, are you able to recognize what Rickey wears on the HR100 photo ?


    • Hi Frederic,

      I got lost at the same place- Boulder Creek pass (top of 2nd climb). Ended up taking a straight line down through the talus- one cliff-out and slow going. But the X-Series still performed well. Usually do that downhill in 8-9’s but ended up with a 28 and an 18, loosing about 25-30 minutes! So it goes (but you would have thought that I would know where the trail is after doing the race 3 times now!).

      As far as Rickey’s shoes, I heard that they were some variant of a FellCross tread on an X-Series, but that is all hearsay. Glad to hear that the S Lab Wings work so well for you- perhaps they will for me as well.

      I have a feeling that there is some new “Kilian” shoe coming out that has not been announced, but only time will tell.

      Best in training! And good luck at Wasatch- a very tough race but Standhope is a good primer…

  5. Yeah, I suppose a lot of people got lost too! I also went down the talus to follow some tracks that I thought were human tracks 😉
    I went back up after I realized it was definitely not the trail. I also would have thought that people having done the race before would not get lost but go figure, the mountains are challenging every time you enter them right ?

    Oh I would love to hear/know more about some new Kilian shoes!!!!

    Thanks, I will definitely need luck for Wasatch! Though it will be brutal, I am really excited for it!!


    • Hi Frederic,

      I did a bit of up and down as well and eventually convinced a few fellow competitors to follow me straight down… safety in numbers? I thought I knew exactly where the trail went at that pass but a year later all is not so obvious!

      Anyway, I will send you an email about Wasatch.

  6. By the way, I mentioned that the S-Lab Wings are my favorite shoes since I bought them last month (and I intend to stock up numerous pairs as well as to get the SoftGround version to replace my FellCross). I am currently running in them pretty much for every running I do (training, racing over 20 miles….).
    While I found them perfectly appropriate for Standhope, I only had one issue with them. The insole moved within the race to end up twisted with a part sticking out of the shoe. Now I’ve never had any problems with all my other salomon shoes (I’ve been wearing exclusively Salomon since 2010 now) and while this topic is not about the S-Lab Wings, I was wondering if you had experienced such a thing with the S-Lab X-Series since they both seem to have the same insole ?


    • Hi Frederic,

      Well I am now in a 5th pair of X-Series and have had no issue with the insole. I too have never had an insole insert move so there may have been a glue failure of some sort of condition that was unique to the Standhope course. Did the insole move on both shoes?

      • Hmmmm….interesting. Yes, both insoled moved. I am wondering if I should not have removed them in the first place. Being often running in wet conditions in OR, i have the habit on removing the insoles from my shoes after each run so that it dries and doesn’t keep moisture in the shoe. But probably those thin S-Lab insoles are not meant to be removed ?
        I am thinking of using the “normal” salomon ortholite insoles as Ive never had any problems with them.

      • I’ve never taken the insoles out except for the one X-Series shoe where the sharp stone penetrated through the sole. But it never moved after putting it back in. I do not take them out regularly and it is decidedly not “wet” here in the high desert mountains of Idaho so my experience may not be a good indicator for your conditions. One suggestion for drying shoes that we use every day for our cross country ski boots which get wet both from sweat and from melting snow- boot driers. I use them on running shoes when I need quick turnover on a wet pair (like for an afternoon run after a wet morning run). Here is one model:

        We have ancient ones (from the 80’s) that still work but do not have the convection like the new ones. The convection is good because it eliminates any issues with hot spots inside the shoe/boot.

  7. Hi Robert,

    Thank you very much for this final update on the X-Series!

    I am very surprised to see how good your outsole looks after so many miles.
    I have worn my Sonic Pro (same outsole, right?) for 250 miles (400km): the outsole is nearly destroyed and cushioning is very tired (I feel “waves” when I put my fingers into the shoe). This outsole is very good but it doesn’t seem to last longer than my previous New balance Leadville and Nike Pegasus Trail.

    I weight 73kg (160 pounds) and my shoes were mainly used during trail sessions (both technical and easy trail paths) and competitions (last one: 55 miles, 18000 ft of positive ascent – 84km, 5500m D+, I finished 14/1200).

    My question is simple: what is your recipe to be so kind with your shoes?
    I am intrigued!

    Thanks a lot,
    José (France)

    • Hi Jose,

      Not sure why you are not getting a similar amount of wear that I have experienced on the X-Series/Sonic outsole. I just tossed a 5th pair of X-Series to the bin after about 1500 km. The outsole is still in good condition but the cushioning is essentially gone. The uppers are indestructible in my experience. I run on a 50/50 mix of buffed trail and rocky technical terrain that includes some sharp igneous (volcanic) strata. My running weight is 57 kg (125 lbs) and I am a predominantly forefoot striker. Perhaps this combination is “gentle” compared to other biometrics. However, when I was wearing the S Lab Sense line I noted a lot more outsole wear at the same distances when compared to the X-Series. I had chalked this up to the use of carbon rubber in the outsole of the X-Series/Sonics. I am surprised that you only got 400 km (250 miles) from your Sonic Pro shoes. Then again I have not put many miles on the Sonic Pro… but the outsole and midsole materials are supposed to be the same. This is just conjecture, but perhaps your biometrics and terrain composition are much more degrading/abrasive than mine.

      Glad to hear that you are taking the Sonics out on technical trails- I think they work very well in such conditions even though Salomon does not advocate for their use in technical terrain. I continue to see photos of Emilie in X-Series/Sonics on technical terrain, but, of course, her skills are on a different level than most of the rest of us! Hopefully the 2017 S Lab Sonic replacement has speed laces, but the new S Lab Sense Ultra looks to be a great mountain/technical shoe…. and I hear that there are some additional new models to be launched in January that will be available in June- this will probably be some derivative of the integrated gaiter “Kilian” shoe that we saw at Zegama.

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