You can't trade out for another runner at mile 70 so why should you wear a shoe that can't go the distance and duration you're running? Salomon realized there was a need for a shoe that can hold up to a 30 to 40 hour ultra marathon so they created the Salomon S/Lab Ultra Glide. Designed specifically for runners who run an ultra between 30 to 40 hours. 

Details 

"So how does as shoe hold up to 30 to 40 hours during an ultra-marathon" you might be asking. Salomon created a dual layer midsole made of highly responsive supercritical Energy Foam on top and stable/durable/cushioned Energy Foam on the bottom. This allows the runner to take advantage of the ability to run early on and the downhills while providing the cushion, stability and durability needed by the 30 hour mark. 

In order to allow the dual density midsole to do its job the outsole is designed to disperse pressure across the surface area of the shoe. By doing so it removes compression points that prevent that shoe from doing its job late in the race. The outsole design known as The Relive Sphere utilizes an arc pattern. In nature the arc is strongest structural shape because it distributes forces equally throughout the shape. When you apply this arc structure to an outsole it creates high levels of durability as well as an instep feel that can last up to 40 hours. 

The combination of these three components allow the Salomon S/Lab Ultra Glide to hold up to the downhills, the power hiking and shock absorption you need late in race. When you're falling apart why rely on a shoe that's going to the do same? You need an ultra running shoe that's there when the gun goes off but most importantly when you hear cowbells at the finish. 

Technologies 

• Relieve Sphere Technology

As mentioned in the description above this technology took the strongest structure in nature and placed in on the outsole. The purpose of these arcs is to prevent specific points of impact that over the duration of an ultra marathon cause hot spots that lead to blistering, pain, muscular damage and finally having to transition to a fresh pair after you've broken down. The 3-dimensional arc disperse forces evenly through the shape. When placed on a trail running shoe it allows impact forces to distributed evenly across a larger surface area minimizing localized damage to the foot. 

• All Terrain Contagrip®

When you're going on an adventure you need to be sure that your footwear can handle wet, dry, loose and variable terrain. The Salomon S/Lab Ultra Glide combined with the Contagrip® means you're ready to handle miles anytime and anywhere regardless of what the weather and geography thrown your way. 

• energyFOAM midsole

Combining EVA and Olefin [OBC] this midsole is responsive, soft and durable. The Olefin block copolymers [OBC] are composed of alternating soft and hard blocks. The soft blocks deliver flexibility and the hard blocks deliver compression resistance. This technology is the foundation of the Salomon S/Lab Ultra Glide. When things get tough late in the the race this bottom layer midsole provides the comfort and stability needed to keep going on the toughest downhills. 

• energyFOAM midsole

A supercritical version of the Engery Foam is the top layer of the midsole created specifically for extra bounce and responsiveness. This allows the shoe to be responsive early in the the race when your legs are still there but provides the extra get up you need later on when you might not want to run the downhills. 

Salomon S/Lab Ultra Glide Specs

Heel to Toe drop 

6mm

41 mm to 35 mm

290 grams 

Eur 42