The S/Lab Ultra 2 updates last year's S/Lab Ultra with only minor changes, so those who have run in the previous version should expect something quite similar with this newest update. The noticeable differences are cosmetic changes to the upper. While the first version had two "wings" that served to join the laces to the midsole of the shoe, wrapping the inside and outside of the foot, the newest version has only one of these wings, toward the rear. The effect here is subtle but positive in our opinion. The older version hugged the foot perhaps a bit too much, making this shoe feel overly narrow, especially in the arch. This version allows for more splay of the forefoot as it lands on the ground, while not hugging the arch quite as tight, but still offers a super secure fit. These changes also led to a weight savings of almost half an ounce per shoe, which is significant, especially for a burly and protective shoe like this one.
The newest version of the S/Lab Ultra 2 in the front, with the original version behind. The shoes remain very similar, with the design of the upper being the only major change. Notice the single "wing" that grips the midfoot on the newest version, while the older version has two of these "wings". Reducing these means the shoe is now a bit lighter, and also allows for more space for the forefoot without it being squeezed so tightly.
For those who have never run in a previous version of this shoe, expect a very high tuned fit that holds the foot securely in place, traction that is good across all types of terrain, including wet rock, and a dense foam midsole that does a great job protecting the foot from underfoot protrusions, but doesn't feel soft and spongy like the foam underfoot in the Hoka Challenger ATR 5 or Altra Lone Peak 4.
They have an 8mm stack height, which allows for significant shock absorption if you are a heel striker, but are never-the-less surprisingly stable on uneven terrain. By far the biggest downside to this shoe is the cost, and indeed, the $180 price tag will surely scare away anyone on a budget. However, for those who want the best performance and aren't as worried about spending a little more to get it, we think this is the best trail and ultra-running shoe you can buy.
The Salomon S/Lab Ultra 2 are a very protective and supportive shoe that fit snuggly around the foot and are optimized for long distance runs. They are the highest scorer in our comparative testing, but also come with the highest price tag.
This shoe presents a complete package when it comes to foot protection. The thick EVA foam underfoot is both super protective, absorbing the majority of any impact with sharp rocks or roots, but is also much firmer than the springy feeling foam found in the Hoka Speedgoat 3 or the Challenger ATR 5. We appreciate the firmer foam because it makes for a more stable, responsive ride that allows us to tackle any type of terrain in this shoe without the loss of confidence on rugged terrain that comes with a lot of foam underfoot.
We also greatly appreciate how well this shoe protects the upper side of the feet. The rubberized toe bumper is robust and can easily absorb the impact of kicking a rock, and the entire mesh upper itself is injected with polyurethane and covered in a solid, rubberized TPU film, significantly enhancing its durability. The upper is easily the most protective that we tested, and adequately covers the usual areas where the mesh upper is the first to tear open. The combination of dual-density EVA underfoot and the solid upper make this the most protective shoe that we tested.
Running across any sort of rough, rocky terrain makes one appreciate the protection their shoe is providing for their foot, but crossing lava fields, like here in the Mt. Jefferson Wilderness of Oregon, makes foot protection essential. This shoe is among the most protective that you can buy.
The outsole of this shoe is patterned with many diamond-shaped lugs that are moderately spaced out and roughly 4mm deep. For trail runners, this is by no means an aggressively lugged shoe, but the rubber compound used is also impressively grippy, made of proprietary Contagrip and designed to grip well on wet surfaces. It is among the grippiest shoes on rock and talus.
It performs equally well on dry and loose dirt, and we are happy that the outsole is made of one solid piece of rubber, rather than many smaller pieces all glued onto the midsole foam. While it isn't nearly as aggressively lugged as the Salomon Speedcross 5, with its huge 6mm deep arrows for grip, and is also not as durable as the new graphene infused rubber found on the soles of the Inov-8 Roclite 290, we still found the traction on this shoe to be among the more effective on all types of terrain.
The traction on this shoe is sticky on rock, while the moderately aggressive lugs do a good job gripping dry dirt, and a reasonable job gripping slippery surfaces like mud and snow.
No shoe in this review does a better job of locking the foot firmly in place, prohibiting it from moving about on off-camber terrain. The interior Endofit sock accomplishes this in conjunction with an exterior rubberized "wing" attached to Salomon's quick lace system. The fact that the foot is held firmly in place at all times greatly adds to the stability of the shoe, giving the confidence to push the speed even when the footing is poor.
The S/Lab Ultra 2's 26mm of foam cushioning under the heel is on the higher end of the spectrum, and it also has 8mm of heel-toe drop, more than we would like to see for a highly stable shoe, but these numbers don't accurately represent the feeling of stability experienced in the field. We think it feels just as stable as some shoes with less drop, like the Scarpa Spin Ultra.
Despite the 8mm of heel-toe drop, which has slowly over the years morphed from "average" to "a lot," the S/Lab Ultra 2 remains relatively stable. A lot of this has to do with how well the shoe grips the foot, allowing for no slippage at all, regardless of terrain, giving great confidence in both take-off and landing.
If you have a narrow foot, then you are in luck! However, if your foot is wider than average, or you have had a hard time with the fit of Salomons in the past (they have long been characterized as making narrow shoes), then you will likely also have problems with the S/Lab Ultra 2. That said, we found these shoes to not be as narrow and constrictive feeling as the first generation of this shoe, due in part to the removal of one of the foot-hugging wings allowing for greater splay in the forefoot. While they are still a bit narrow compared to the competition, they are no longer prohibitively so in our opinion.
There is no doubt that the seamless upper is constructed to a top-notch standard of quality, and while they don't use a ton of cushioned padding on the inside in the same way that the Saucony Peregrine ISO does, they are comfortable simply because they fit so snugly, similar to the fit of the La Sportiva Kaptiva.
One of the reasons the S/Lab Ultra 2 is so comfortable is because it hugs your foot so snugly. The quicklace system, made of kevlar cord, plays a critical role in cinching the shoe down over the foot. Conveniently, the cinch buckle that holds the laces tight has its own garage in the top of the tongue.
In the water test, we found that the S/Lab Ultra 2 was far and away the top performer, so much so that they almost seem like outliers. Salomon designed this shoe to perform well in wet conditions, and our findings certainly back this up.
Our size 11 weighed in at 22.7 ounces per pair. While this isn't exactly light, it isn't cumbersome either considering how much shoe you are getting.
This shoe feels burly and protective, with a ton of rubberized overlays for added protection and durability, though surprisingly, they aren't heavier. They are about half an ounce per shoe lighter than the previous version, while the design remains virtually the same, so kudos to Salomon for improving on an already great product. For reference, they are virtually the same weight as the Hoka Speedgoat 3 and are lighter than the Salomon Speedcross 5.
At 22.7 ounces per pair, these shoes are not the lightest that you can buy, but are also not nearly as heavy as one might expect considering their incredible protection and heavily reinforced upper.
While these shoes feel very precise while running in them due to their amazingly conforming fit, they certainly are not super sensitive. There is a thick, dense piece of foam underfoot that does a great job of protecting the feet, but quite obviously also dampens most of the trail feel.
That said, much of the thick foam is located under the heel, but under the forefoot the cushioning is thinner, allowing for a bit more trail feel in that area of the foot, and some added sensitivity. We think they strike a pretty fair balance, especially considering the level of foot protection.
These shoes are more protective than they are sensitive, but the forefoot also features 8mm less compressed EVA foam underfoot, so there is more trail feel under the toes and balls of the feet.
The S/Lab Ultra 2 provides the foot protection and stability to be able to run for ultra distances, which is exactly what they were designed for. Perhaps no other shoe we have worn is more suited to longer ultras up to 100 miles without compromising on performance. However, these shoes are also a great choice as everyday trainers and can tackle any terrain.
The S/Lab Ultra 2 is ideal for pretty much any sort of terrain, but is specifically designed for ultra distances and racing, where its excellent foot protection will really shine.
With such a high retail price, they are far and away the most expensive we have ever tested! That is a dubious distinction, and should rightly make you consider if this is the type of shoe you need. However, with the highest cost comes the highest performance. While we have run lots of miles in these shoes, and their predecessors, without experiencing early breakdowns, there are rumors online of some early mile durability concerns, which purchasers may want to consider. If this shoe fits you, then we think it is worth the money, but budget-conscious runners can find many other amazing shoes at a fraction of the cost.
The Salomon S/Lab Ultra 2 is the highest rated shoe in our review, due to its incredible foot protection, super stable ride, sticky outsole, and snug form fit. It is the most highly refined trail running shoe we have ever worn, and while it is still slightly narrow, is more wearable for those with average width feet than the previous version. For those willing to pay the price, we don't think there is any better shoe you can buy. However, with such a high price tag and a particular fit, this shoe is likely not for everyone.
With the volcanic peak of Mt. Jefferson, the second highest mountain in Oregon, in the background, we are running in and testing the Salomon S/Lab Ultra 2 over dry dusty trails, through lava fields, and also in deep Ponderosa Pine forests.