Our verdict

The Salomon Thundercross bursts onto the trail running scene as a versatile shoe, capable of handling a diverse range of terrains and paces, all at a reasonable $140. We found its traction on challenging terrain quite impressive, alongside a durable and spacious upper, and a midsole that delivers a bouncy ride. In our tests, we noticed it falls short in breathability, and the 3.0-mm heel-to-toe drop may not suit all runners. However, we believe Salomon's endeavor to address a previously unfilled gap in their lineup is praiseworthy, and the Thundercross is an excellent option for those in search of a versatile shoe for their trail runs or hikes.

Pros

  • Exceptional stability
  • Highly durable
  • Versatile across various paces
  • Outsole provides excellent grip, even on inclines
  • Ideal for those with wide feet
  • Impressively lightweight
  • Performs well on multiple surfaces
  • Quiet on roads
  • Reasonably priced at $140

Cons

  • Not for summer
  • Could benefit from additional cushioning
  • The very low drop may not suit everyone

Audience verdict

93
Superb!

Who should buy

We recommend the Salomon Thundercross for:

  • Adventurers seeking a versatile trail running shoe that does a great job even on challenging terrain.
  • Salomon enthusiasts looking for a single, do-it-all shoe for every trail experience.
  • Trail runners who favor midfoot or forefoot striking technique and are in search of a low-drop shoe but are not fans of Altra.

Salomon Thundercross

Who should NOT buy

While the Thundercross caters to a broad spectrum of trail runners, in our view it falls short in certain aspects. Its notably low heel-to-toe drop may not suit heel strikers, who might find a better fit with shoes offering a higher offset, like the Nike Pegasus Trail 4 or the Merrell Nova 3.

Additionally, we think it's not the ideal choice for ultra distances due to its limited cushioning. For the long stuff, we suggest considering the Brooks Cascadia 17 or the Hoka Mafate Speed 4 as more suitable alternatives.

Salomon Thundercross

Breathability

One of the first things we love to do in the lab right after unboxing a shoe is to touch the upper and try to gauge the breathability. In this case, it was pretty clear from the start that airflow would be extremely limited. But, we needed to see how it would perform in the smoke test!

Our observation confirmed that airflow is minimal, with only a bit of smoke escaping through the upper part of the tongue. That's a 1/5 rating, and if we could go lower, we would. It's on par with most Gore-Tex shoes.

Looking for more evidence of the limited airflow, we went to examine the cut-in-half shoe under our light. As expected, no light passed through the upper, confirming the virtually nonexistent ventilation.

Next, we turned to the microscope.

Salomon Thundercross microscope

There, we observed a thick, dense engineered mesh with absolutely no ventilation holes—not even in the threads. This is clearly a deliberate design choice by Salomon, likely aiming for durability and suitability for cold climates.

Salomon Thundercross close up

Finally, the upper isn't elastic at all, so it won't stretch over time, meaning ventilation isn’t likely to improve.

Test results
Thundercross 1
Average 3.3
Compared to 63 trail running shoes
Number of shoes
1
Breathability
5

Durability

Toebox durability

Uppers with limited ventilation often excel in our toebox durability test, so we were quite excited to put the Salomon Thundercross to the test.

After our rigorous evaluation, we awarded it a 4/5 score, a truly impressive result. The upper boasts a substantial protective layer, making durability a standout strength of this shoe.

Salomon Thundercross Toebox durability
Test results
Thundercross 4
Average 2.9
Compared to 43 trail running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

The heel padding doesn't match the fantastic durability of the upper, but with a 3/5 score in our Dremel test, it passes for us.

In fact, this can sometimes be the best outcome. Shoes with top scores in this test can often be uncomfortable due to having less padding or harsher fabric in this area.

Salomon Thundercross Heel padding durability
Test results
Thundercross 3
Average 2.8
Compared to 41 trail running shoes
Number of shoes
1
Heel padding durability
5

Outsole hardness

We measured the outsole hardness with our Shore C durometer, and it registered 83.5 HC.

This is near the average, which is what most brands aim for to strike a balance between durability and grip.

Salomon Thundercross Outsole hardness
Test results
Thundercross 83.5 HC
Average 85.1 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 86 trail running shoes
Number of shoes
72.5 HC
Outsole hardness
95.0 HC

Outsole durability

As we expected, the average hardness resulted in average durability.

The 0.9 mm indentation we found in the lug after our last Dremel test is pretty much in line with a typical trail running shoe.

Salomon Thundercross Outsole durability
Test results
Thundercross 0.9 mm
Average 0.9 mm
Compared to 36 trail running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

Using our precision tools, we pinpointed a 2.5-mm thick outsole, which is more than sufficient for this shoe.

It might slightly mute the ride, but without a rock plate, we appreciate that Salomon included at least an average thickness here to protect our feet from potentially sharp rocks.

Salomon Thundercross Outsole thickness
Test results
Thundercross 2.5 mm
Average 2.5 mm
Compared to 86 trail running shoes
Number of shoes
1.0 mm
Outsole thickness
6.5 mm

Weight

This is one of those shoes that looks bulkier than it actually is. Salomon did an excellent job keeping it below the 10-oz benchmark, with a weight of only 9.6 oz or 271g.

Salomon Thundercross Weight
Test results
Thundercross 9.56 oz (271g)
Average 10.37 oz (294g)
Compared to 86 trail running shoes
Number of shoes
7.51 oz (213g)
Weight
13.37 oz (379g)

Cushioning

Heel stack

However, the main explanation of the weight lies in the low stack height.

Salomon Thundercross heel

At just 27.6 mm, there's significantly less foam in the heel than usual, making the shoe less appealing for rearfoot strikers.

Salomon Thundercross Heel stack
Test results
Thundercross 27.6 mm
Average 32.2 mm
Compared to 86 trail running shoes
Number of shoes
16.1 mm
Heel stack
40.4 mm

Forefoot stack

In the forefoot, we measured a standard stack height of 24.6 mm.

This is the ideal approach for an all-rounder shoe, so it's clear that Salomon wants the Thundercross to be versatile—suitable for a bit of everything in terms of both paces and distances!

Salomon Thundercross Forefoot stack
Test results
Thundercross 24.6 mm
Average 24.3 mm
Compared to 86 trail running shoes
Number of shoes
15.2 mm
Forefoot stack
33.8 mm

Drop

However, it's not the best option for everyone. With an extremely low drop of 3.0 mm, it's mainly designed for forefoot strikers and possibly midfoot strikers.

Heel strikers need to be comfortable with low-drop shoes like those from Altra; otherwise, we don't think they're a great choice for them.

Salomon Thundercross Drop
Test results
Thundercross 3.0 mm
Average 8.1 mm
Compared to 85 trail running shoes
Number of shoes
0.1 mm
Drop
15.2 mm

Insole thickness

The insole follows the same pattern as the outsole—it sticks with the average. At 4.3 mm, it fits perfectly for an all-rounder trail running shoe.

Salomon Thundercross Insole thickness
Test results
Thundercross 4.3 mm
Average 4.7 mm
Compared to 86 trail running shoes
Number of shoes
2.7 mm
Insole thickness
7.3 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

Now, let's go with the midsole. The Thundercross is equipped with EnergyFOAM, an EVA+OBC mix.

Blending OBC (Olefin) with EVA brings several advantages, like enhanced resilience and energy return. We clocked its softness at 19.4 HA.

We can confidently confirm that the shoe doesn’t feel like a typical, hard EVA midsole. In fact, it offers a truly enjoyable and fun ride!

Salomon Thundercross Midsole softness
Test results
Thundercross 19.4 HA
Average 26.3 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 86 trail running shoes
Number of shoes
9.4 HA
Midsole softness (soft to firm)
50.3 HA

Midsole softness in cold

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

This shoe, with its upper designed for low temperatures, is expected to perform well in winter. To test this, we placed the shoe in the freezer for 20 minutes and then re-tested it. We found that the softness changed to 25.9 HA.

Salomon Thundercross Midsole softness in cold
Test results
Thundercross 24.6 HA
Average 32.4 HA
Compared to 82 trail running shoes
Number of shoes
11.8 HA
Midsole softness in cold (soft to firm)
55.0 HA

Difference in midsole softness in cold

That's a 27.1% increase, which is acceptable. It ensures there won’t be incredibly big differences in how the shoe feels in winter, which is what we expected from a base of EVA—typically underperforming in cold weather—mixed with OBC, which helps to boost its performance.

Test results
Thundercross 27.1%
Average 27.1%
Compared to 82 trail running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Stability

Lateral stability test

Though the Thundercross isn't a stability shoe by design, on certain terrains it performs as admirably as one.

The combination of its relatively low stack, a well-balanced midsole, and a low drop, all contribute to an undeniably stable ride. And we loved it.

Torsional rigidity

The lower stack height plays a key role in the stable ride we talked about earlier. However, a major factor in this stability is the shoe's high torsional rigidity that we rated at 4/5.

Test results
Thundercross 4
Average 3.5
Compared to 80 trail running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The heel counter actually takes the opposite approach. With a rating of only 2/5, it's soft, clearly aiming to be comfortable for all-day wear and to avoid an intrusive ride.

At the same time, given its low drop, there's no need to add much guidance in the rearfoot, as the shoe is already tailored towards midfoot and forefoot strikers.

Test results
Thundercross 2
Average 3.2
Compared to 78 trail running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

The forefoot of the shoe, at its widest point, measures 113.0 mm. This adds to the array of features in this shoe that hover around average, aiming to create the ultimate jack-of-all-trades.

Salomon Thundercross Midsole width in the forefoot
Test results
Thundercross 113.0 mm
Average 111.7 mm
Compared to 86 trail running shoes
Number of shoes
102.1 mm
Midsole width in the forefoot
126.0 mm

Midsole width in the heel

In the heel, we measured a midsole width of 88.6 mm, which is a safe approach.

It's not as wide as what you'd typically find in a stability shoe, but at the same time, it's wider than the narrowest, more aggressive shoes on the market.

Salomon Thundercross Midsole width in the heel
Test results
Thundercross 88.6 mm
Average 89.7 mm
Compared to 86 trail running shoes
Number of shoes
77.2 mm
Midsole width in the heel
109.3 mm

Flexibility

Stiffness

The shoe is rigid torsionally, but it's much more flexible lengthwise, which aligns with Salomon's intention for it to be suitable for walking or hiking as well. In our 90-degree bend test, we only had to apply 29.2N of force to bend the shoe to the desired point.

Test results
Thundercross 29.2N
Average 29.3N
We use an average of four tests. The video shows one of those tests.
Compared to 86 trail running shoes
Number of shoes
10.5N
Stiffness
54.5N

Stiffness in cold

We repeated the 20-minute freezer test to understand the shoe's stiffness in harsh winter conditions. After that, we needed to exert 36.3N of force to bend the shoe.

Test results
Thundercross 36.3N
Average 40.3N
Compared to 83 trail running shoes
Number of shoes
11.9N
Stiffness in cold
92.1N

Difference in stiffness in cold

That's just a 24.2% difference, a great result that outperforms almost every other trail running shoe. Why does this happen?

As we explained earlier, mixing EVA foam with OBC results in much better performance for the midsole and ensures consistency across a range of temperatures.

Test results
Thundercross 24.2%
Average 38.2%
Compared to 83 trail running shoes
Number of shoes
0%
Difference in stiffness in cold
102%

Grip / Traction

Lug depth

We're now focusing again on the outsole, specifically one of the most crucial aspects of any trail running shoe—the lugs of the Contagrip outsole.

Salomon Thundercross lugs

Salomon has chosen 4.0-mm lugs, which are slightly longer than what most all-around trail shoes typically have (3.0 to 3.5 mm).

We think this is a smart move from Salomon, as it positions the shoe better for technical terrain or muddy areas, rather than just being suitable for easy trails like fire roads.

Salomon Thundercross Contagrip

Additionally, the lug pattern significantly differs from road-to-trail shoes or the most versatile ones. We observed aggressive, chevron-shaped lugs, designed to excel on downhills and uphills, while sacrificing a bit of traction on completely flat trails.

Let's say that it sits in the middle of the Sense Ride 5 (easy trails) and the Speedcross 6 (challenging terrain).

Salomon Thundercross Lug depth
Test results
Thundercross 4.0 mm
Average 3.5 mm
Compared to 86 trail running shoes
Number of shoes
1.7 mm
Lug depth
5.8 mm

Size and fit

Toebox width at the widest part

Salomon is highly known in the trail running world for its snug, narrow uppers, but the Thundercross actually defies this trend.

Salomon Thundercross

Measuring at 102.7 mm, it's one of the widest Salomon shoes we have ever tested in the lab.

Salomon Thundercross Toebox width at the widest part
Test results
Thundercross 102.7 mm
Average 98.8 mm
Compared to 86 trail running shoes
Number of shoes
92.0 mm
Toebox width at the widest part
104.9 mm

Toebox width at the big toe

The toe cap, measuring a generous 79.5 mm, is wider than average, making it an ideal fit for those with wide feet, particularly in the toe region.

Salomon Thundercross Toebox width at the big toe
Test results
Thundercross 79.5 mm
Average 78.1 mm
Compared to 48 trail running shoes
Number of shoes
70.5 mm
Toebox width at the big toe
89.5 mm

Tongue: gusset type

The Thundercross doesn't have a gusset in the tongue, but its boot-like design will prevent most debris from entering the shoe. However, we would have appreciated at least a semi-gusseted tongue.

Salomon Thundercross Tongue: gusset type
Test results
Thundercross None

Comfort

Tongue padding

With a 7.3 mm thickness, the tongue offers ample padding for comfort, even on long runs.

Salomon Thundercross QuickLace

Plus, over-tightening the laces won't be an issue thanks to Salomon's patented Quicklace system. This feature often sparks a love/hate relationship among many runners due to its unique design.

Salomon Thundercross Tongue padding
Test results
Thundercross 7.3 mm
Average 6.3 mm
Compared to 86 trail running shoes
Number of shoes
1.5 mm
Tongue padding
12.2 mm

Heel tab

Despite having the lace pocket tab in the tongue area, we didn't find a heel tab on the shoe. However, from a functional standpoint, it doesn't really need one.

Salomon Thundercross Heel tab
Test results
Thundercross None

Removable insole

Like many Salomon shoes, the insole in this model comes from a partnership with Ortholite. However, it's not as flared as in other models. And you can easily remove it and replace it with a third-party insole without any issues.

Salomon Thundercross Removable insole
Test results
Thundercross Yes

Misc

Reflective elements

The Thundercross lacks any reflective elements, which is quite disappointing for a trail shoe designed for all-day, off-road adventures. 

Salomon Thundercross Reflective elements
Test results
Thundercross No