Salomon X Ultra 4 GTX review

Who should buy the Salomon X Ultra 4 GTX

Whether or not you have been a fan of Salomon’s X Ultra collection, this waterproof hiker can win you over with its multi-faceted engineering and modern design. The X Ultra 4 GTX is for you if you want:

• hiking footwear with the best waterproofing membrane
• shoes with deep and grippy lugs to tackle soft and soggy trails
• a sturdy pair of hiking shoes to power through demanding trails without resorting to a pair of hiking boots

Who should NOT buy the shoe

If you want a lower heel collar and a more traditional lacing system, we recommend opting for the Merrell Moab 3 GTX. 

If you want a more breathable GTX hiking shoe, we can vouch for the Adidas Terrex Swift R3 GTX.

Salomon X Ultra 4 GTX: An enhanced successor

The 4th-gen X Ultra GTX directly picks up from where its predecessor left off. The most notable updates include the following:

Safer landings, smoother transitions. We discovered that the Ultra 4 helps you land on your heel more safely and make smoother transitions (almost like gliding) on rugged terrain.

Trimmed weight. We confirmed that the X Ultra 4 GTX is lighter than its predecessor by approximately 20 to 40 g a pair.

Better balance of stability and flexibility. The new chassis stiffens the midfoot zone of the shoe while giving the forefoot increased flexibility. Translation: You will get both solid balance and more toe-off control in the X Ultra 4 GTX.

Watertight upper for wet and cold conditions

We are very impressed with the waterproofing provided by this GTX hiking shoe. However, we still don't suggest choosing this shoe for warm weather due to its lack of breathability.

Pumping smoke through the shoe's toebox material, we rated its breathability as 1 out of 5 (the least breathable on our scale).

Salomon X Ultra 4 GTX (left) vs. Adidas Terrex AX4, a non-waterproof shoe (right)

In addition, you can see how the shoe's upper does not let even a bit of light through.

Apart from the GTX membrane, the shoe uses a tightly woven textile with a durable water-repellent (DWR) coating. We learned that this helps seal out light rain and snow.

We took some microscope photos of the water-repellent textile.

The spaces between the weaves are barely present.

On the downside, we are against fully submerging the shoe into a puddle or a crossing, as we found that the water would get inside through the shoe mouth and it would take forever to dry because of the GTX.

If you anticipate stepping deeply into the water, consider the high-top version of the shoe.

And if you need an option for summer hikes, there is a non-waterproof iteration of the shoe as well.

Mind-boggling plushness on mile one

The Salomon X Ultra 4 GTX is immensely comfortable right from the get-go. We are particularly amazed by the shoe's super-comfy padding.

The tongue is well-padded without being too much. We measured its thickness at 9.4 mm which is thinner than the average 13.3 mm among hiking footwear.

The upper is very sturdy, with thicker synthetic overlays adding support and protection in all the right places. It does not stretch at all.

The well-cushioned antimicrobial Ortholite insole also blew us away.

Measuring the insole thickness in its heel area, we found that it is 5.7 mm thick. This is an average thickness for hiking shoe insoles.

Clunkiness cancelled

Its low weight makes it a real standout. We are stunned by how Salomon managed to pack so much support, protection, and grip into the lighter-than-average X Ultra 4 GTX.

The shoe weighs 13.3 oz (378g) while the average of waterproof hiking shoes is 14.4 oz (409g).

The X Ultra 4 GTX's sticky business

We also vouch for this shoe to have a super-adhesive outsole as it provides us with optimal traction even on loose dirt.

This Salomon shoe comes with some of the deepest lugs that can be found on hiking shoes - 4.5 mm. For reference, the average is 4.0 mm.

Extraordinary support system

Its heel zone gave us a mighty good sense of security.

In a manual assessment of the heel counter, we rated its stiffness as 5 out of 5 (the stiffest in our range). This typically translates to a firmer heel hold as well as increased stability.

Hit-or-miss lace management

Even though we appreciated how quick and easy it is to regulate the Quicklace system, there are moments when tucking the remainder of the shoestrings is a bit of a struggle.

The sky-high clearance of the X Ultra 4 GTX

We are not entirely sold by the shoe's ankle cuff being too high—higher than the 3rd iteration's. 

The stabilising Salomon X Ultra 4 GTX

Upon testing the shoe on challenging terrains like rocky trails, steep downhills, and heavily rooted areas, we can verify the stable base provided by the Salomon X Ultra 4 GTX. We even felt confident hiking with a loaded backpacking pack.

Among the stability-enhancing factors, the shoe's Active Support system, as well as the wide sole, is what did it for us.

The wide and sturdy Active Support straps are interconnected with the lacing system to prevent ankle rolling at all times.

Measuring the sole in its widest parts, we found that it is 108.2 mm in the forefoot and 84.2 mm in the heel. This is not much wider than the averages of hiking shoes though: 107.7 mm and 85.3 mm respectively.

No sacrifices in flexibility

We noticed a fine balance of stability and flex that the Salomon X Ultra 4 GTX achieved with the new chassis. We never felt restricted when bending our feet as the shoe still had sufficient flexibility.

Checking the shoe's resistance to being bent, we found that the X Ultra 4 GTX is 31% more flexible than hiking shoes on average. In fact, the shoe is more like a trail running shoe in this regard. It is only 7% stiffer than the latter. 

Backing up our lab test with a manual assessment, we rated the shoe's longitudinal and torsional flexibility as 3 out of 5 (where 5 is the stiffest).

But watch out for the chilly weather! Leaving the shoe outside overnight in low temperatures is going to make it noticeably stiffer. Then, you will have to break the shoe in to get that flexibility back.

After keeping the shoe in the freezer for 20 minutes, we measured its flexibility again. It got 75%(!) stiffer! This is way more than the increase in other hiking shoes (around 45%).

Well-balanced cushioning

The cushioning unit of the Salomon X Ultra 4 GTX makes it feel a lot like a trail running shoe. We detected that the shoe hits a sweet spot between underfoot protection and ground feel. This setup helps us feel stable and surefooted but also supported on longer distances.

According to the brand, the shoe's heel stack is 31.5 mm and its forefoot stack is 20.5 mm, making the heel-to-toe drop 11 mm.

Using a pair of callipers, we measured the shoe's heel stack at 30.9 mm and its forefoot at 20.0 mm, giving us a 10.9-mm drop. The numbers are very close to those provided by Salomon.

We also measured the shoe's foam softness with the help of a durometer. At room temperature, it turned out to be right in the middle - neither plush nor firm.

It is very similar to the cushioning of the Merrell Moab 2 GTX hiking shoe.

Salomon finally takes care of wide feet

As we have worn the previous iteration of the X Ultra, we couldn't help but notice that the 4th edition came out with some extra space in the toe box.

We measured the shoe's toebox width in two areas:

• the widest part: 99.9 mm (1 mm wider than average)
• the area around the toes: 79.2 mm (6.1 mm wider than average)

The fact that the toebox narrows less towards the toes than some other hiking shoes creates more toe room in the Salomon X Ultra 4 GTX. We can state that it got a big step closer to being wide-foot friendly. But it's still not there yet.

So, if you have wide feet, try getting this shoe in 2E - Wide.