Article by Sam Winebaum
S/Lab Ultra Glide ($250)
Introduction
Salomon introduced the 2025 S/Lab Ultra Glide at UTMB positioning their most max cushion (41mm heel / 35mm forefoot) to date trail runner as a shoe for long hours on the trail at more moderate paces. Salomon’s goal was to create “run in comfort from mile 1”.
It is not so much an elite ultra racer, as S/Lab shoes traditionally have been often specifically inspired by the needs of certain athletes, but is intended as a shoe for those out for 30 to 40 hours during a hundred miler. It follows the similar mid pack focused S/Lab Spectur 2 for road as a state of the art racer/trainer for the not so fast, although some Salomon elites raced it a UTMB. And while focused as an ultra trail shoe I have found it to be a truly superb road and door to trail shoe. Actually one of the best road shoes of 2024 for me.Please read on for the shoe details (many!) and the results of our testing.
The geometry is unique and for sure innovative. We have a layer of supercritical Energy Foam+ below the foot as a central core with Energy Foam (as found in the Genesis) surrounding and below. This is a softer midsole for sure from Salomon and for a trail shoe with great energy return.
The high rear midsole side walls provide stability and are so high Salomon had to mold the outer Energy Foam in two sides/pieces.
They then discovered that the glue joining the 2 sides plus the rocker creates a mild propulsive effect while also stabilizing, without any plate, which is something I clearly discovered on the run.
The showpiece of the geometry is a new technology called Relieve Sphere. It is made up of concave strategically placed circular elements located at underfoot pressure points front to back.
I found they not only work as intended but also provide ground feel, relief from shock pressures and, a very natural ride ,but one that had some limits in more technical terrain due to the softness of the foam and constraints they create for outsole lug coverage,
Sitting on a broad platform to help stabilize the soft foam, with a roomy comfort focused fit the upper is made of a combination of a stretch knit toe box mono mesh and knit to the rear and overlays, No Matryx here.
The Ultra Glide weighs a very commendable 10.05 oz / 285g in my US8 /EU 41 1/3 sample.
I am usually a US8.5 with the size down at least in US size here correct for my narrow to medium feet. This shoe will for sure be far friendlier than prior Salomon for broader higher volume feet
The S/Lab Ultra Glide follows in the footsteps and purpose of the lower stack about the same weight Ultra Glide (RTR Review), one of our favorite long run shoes of 2023 with an all new geometry, the dual foams and Relieve Sphere technology.
I received my pair at Salomon’s introduction event on the slopes of Le Brevent where participants ran varying distances on steep terrain with stations presenting the shoe and other 2025 Salomon gear along the way. \
There was even a station presenting the Ultra Glide’s characteristics, design and styling with food art designed to reflect in shape and even tastes. Below Geometry.
Since the event, I have hiked them 10 miles on smooth terrain, and run 7 miles on pavement, gravel and moderate trails.
My testing so far shows it sits in their ultra lineup as less technical trails focused than the S/Lab Ultra FDH and as a more cushioned alternative to the S/Lab Genesis and Genesis. It is also a sensational road shoe as a non plated super trainer with grip for gravel if need be.
Pros:
- Remarkably lightweight at about 10.2 oz / 289g (US 9 equivalent) for a max cushion, high stack, broad platform trail shoe
- Relieve Sphere geometry underfoot provides a pressures free ride and great ground feel
- Very versatile from somewhat less tech trails to road and for hike paces
- Also a superb road run shoe
- Effective plateless rocker geometry
- Comfortable, broad fitting upper
Cons:
- Fit runs large and roomy upfront and could use more front and mid foot lockdown for tech terrain
- Furthest forward medial Relieve Sphere‘s compression creates an overly thin toe off on that side.
- Outsole lug coverage (and grip) is constrained by Relieve Sphere.
- Early outsole wear at the front where lug coverage is sparse
Most comparable shoes
Salomon Ultra Glide
La Sportiva Prodigio Pro (2025)
Hoka Mafate Speed
Hoka Speedgoat
New Balance Fresh Foam More Trail
Stats
Sample Weight: men’s 10.05 oz / 285g US8
Stack Height: men’s 41 mm heel / 35mm forefoot ( 6mm drop)
Platform Width: mm 90 heel / 85 mm midfoot / 115 mm forefoot
$250. Available 2025
First Impressions, Fit and Upper
The upper is a combination of non-stretch mono mesh with minima knit to the rear and midfoot with increasing amounts of knit and less mono mesh over the top of the toes.
Very elaborate, it appears Salomon has combined two very different materials: a somewhat stretchy knit with a non stretch mono mesh in one continuous knitting process with softer knit against the foot throughout the upper.
The heel area is semi rigid with support at its sides from the very high rising foam side walls which reach almost to the top edge of the collars. These foam walls extend forward seating the foot down into the shoe allowing the upper to be thin and pliable yet supportive at the same time.
The tongue is gusseted its entire length to create a sleeve. Not a leatherette type tongue, it is a slightly stretchy very lightly padded mesh material.
Of course we have Salomon’s Quicklaces with a “garage” which is easy to access,
The toe box area over the toes has the most knit material in the upper and is broad and quite unstructured. A moderately soft and pliable toe bumper keeps the foot in place and provides front protection.
This toe box is clearly the broadest and most accommodating of any Salomon I can recall and should accommodate broader higher volume feet and swelling during long runs and races.
I think it goes a touch too far in the “comfort” department and could have a bit more structure and front lockdown especially considering the high stack height and soft foam. It was perfectly fine on moderate trails, at hike paces everywhere and on road but when things got rougher it was a bit shakier. Understanding the product brief as a shoe for the 30-40 hour 100 mile racer, Salomon had to balance many hours comfort on foot with performance and they do get close. It turns out some Salomon elites also wished for some more front structure and their prototypes have it.
I found the Ultra Glide breathable and debris resistant but have not gotten them fully soaked to determine draining and drying times.
As previously said, the fit is about correct in length in my test pair in terms of sizing but not in terms of shoe marking. I am usually a US8.5 and here the sample is labeled US8 / EU 41 ⅓. I do think for a more precise fit given the stretch upfront I could go a half size down US for my narrower to medium feet.
Midsole & Platform
The midsole has a central core (at the foot top layer) of supercritical Energy Foam + with a soft 42A Shore firmness rating. The central core is the same foam as found in Salomon’s S/Lab Spectur 2 and S/Lab Phantasm 2 road racers
The outer carrier and at the ground bottom layer is Energy Foam with a 45A Shore firmness rating, the same firmness and foam as in the Genesis and S/Lab Genesis and I believe also non S/Lab Ultra Glide
With its 41mm heel and 35mm forefoot we have lots of deep, deep yet also energetic cushioning here. This is the “softest” Salomon trail shoe yet for me and by far the most cushioned. It is also the softest and most deeply cushioned trail shoe that can actually move along on trails I can recall.
To make the big stack of soft foam “functional” for trail running and to enhance long hours of trail comfort Salomon incorporates three elements:
The platform is broad at 90 heel / 85 mm midfoot / 115 mm forefoot. When those high sidewalls are also brought into the picture with the 90mm wide heel we have great heel stability here and both were clearly essential to stabilize the rear of the shoe and do so,
Salomon tells us the high sidewalls presented a manufacturing challenge, and then an opportunity, as the whole bottom carrier which includes them couldn’t be molded in one piece. So it was molded in two sides and glued together down the center.
Salomon tested various versions, some with carbon and other plates but found that the glue line down the center plus the rocker geometry provided enough stiffness and rolling motion that a plate was not required for the shoe’s purpose and leaving it out would save weight. I generally agree but wonder what a thin woven plate might do up front to stabilize and provide a touch more propulsion.
The third key element, and the most innovative are the Relieve Spheres underfoot geometry,
The concave elements are designed to relieve foot pressures at key points and were designed using lab data. They include the toe off area, metatarsals, just ahead of midfoot, the arch and heel.
On the run there is a sensation of not only pressure relief but of a natural ground conforming feel. On the road the spheres lead to a comfortable well cushioned feel with minimal shock transmitted.
Given the huge stack of foam I am not sure the heel Sphere is really required. The arch and midfoot to metatarsal Spheres are highly effective.
The very front Spheres are a miss for me as they create an overly thin very front of the shoe, compressing too far. I think they could be eliminated or reduced in depth. This would also allow for a more extensive outsole lug coverage up front as steep loose gravel toe offs had bit more slip than I would like.
Outsole
The outsole is Salomon’s excellent Contagrip rubber with 4mm lugs. Given the Spheres cavities upfront and at the heel, the density of lug coverage is somewhat lighter there than I might prefer but for moderate trail terrain and paces the tradeoff for the Spheres tech, lighter weight and smooth non slappy ride on any firm terrain is worth it.
This flavor of Contragrip appears to be on the soft side which enhances the ride but which, in my early non final production pair is showing below average wear up front at 40 miles of running and hiking on often rough rocky terrain and hard smoother surfaces including road.
I think the relatively low number of front lugs given the Spheres is putting additional pressure on those lugs on toe off.
I would add that at 40 miles the Ultra Glide, despite the giant 35mm front stack height has a relatively snappy flex point located where the laces end. Good!
Ride, Conclusions and Recommendations
The Ultra Glide has a friendly, energetic and deeply cushioned ride. This is one versatile shoe with a focus, as intended on the ultra runner who is mid pack to back of pack.
Salomon clearly realized that a large segment of trail runners were moving to highly cushioned forgiving shoes such as Hoka’s Speedgoat and Mafate Speed. While their Genesis and S/Lab Ultra FDH were fine options, a softer more energetic ride and more comfort focused upper was in order and thus the Ultra Glide.
I have very much enjoyed all my runs and hikes in the Ultra Glide. Its strengths are at hike paces on any terrain, any uphills, smoother terrain on the run and interestingly on the road where they easily compete with any of the max cushion unplated super foam cushioned trainers such as Hoka’s new Sklyflow, The Brooks Glycerin Max 2 and for sure the ponderous Fresh Foam More.
The comfort focused upper and deep cushion softness starts to make things shakier on more technical terrain at faster paces. I think it could be perfected by dialing in the toe box hold a bit more, eliminating the very front Spheres or increasing the front proportion of firmer Energy Foam there and increasing the front outsole lug coverage there somewhat.
All in all the S/Lab Ultra Glide is one fun shoe. Thoroughly modern in construction and innovative via its Relieve Spheres, if long hours comfort on the trail (and even road) with a lively high energy big smiles ride is your thing it will be worth considering in 2025. A most versatile shoe!
Sam’s Score: 9.4/10
Deductions for: a bit more front hold and structure and for more very front outsole coverage and big toe toe off area cushion depth and early front outsole wear.
😊😊😊😊😊
The S/Lab Ultra Glide will be available late 2024, early 2025
Salomon S/Lab Ultra Glide Video Review (13:52)
Tester Profiles
Sam is the Editor and Founder of Road Trail Run. He is in his 60’s with 2024 Sam’s 52th year of running roads and trails. He has a decades old 2:28 marathon PR. These days he runs halves in the just sub 1:40 range if he gets very, very lucky. Sam trains 30-40 miles per week mostly at moderate paces on the roads and trails of New Hampshire and Utah be it on the run, hiking or on nordic skis. He is 5’9” tall and weighs about 164 lbs, if he is not enjoying too many fine New England IPA’s.
SALOMON RUNNING
Men's and Women's SHOP HERE
8 comments:
Hi guys, looks like a fun shoe but i was looking at the older reviews here: https://www.roadtrailrun.com/p/blog-page.html searching for something specific about the Genesis model and realized that all the links on that page are broken, could you please fix that? : ) thanks.
Same here!
Hi guys, this should be fixed now. Sorry about that.
Hasn't change for me, the section All Reviews still contain /blog/page/edit links
It takes a while till the page changes are online. From what I can see, the links work again.
The last picture on this review that shows the lugs, how many miles on the shoe? Looks like some significant wear on the lugs.
"Fit runs large and roomy upfront and could use more front and mid foot lockdown for tech terrain"
Salomon usually is way too narrow.
So Salomon Large and Roomy might actually be just right for once.
I would love to hear how the sphere actually work. Also gluing together the bottom down the middle, why was that done? Does that create a weakness for separation? How much technical down hill running was actually done in these to write a review? How many miles do you have on them now and can you show wear patterns?
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