Nike ACG Mountain Fly 2 Low review

Adding this Nike ACG to your rotation should be as intuitive as the ABCs if:

• You are looking for a new pair of sneakers but you want it to be extra durable and very breathable.
• You want to feel safe and sound, so you need stable footwear that offers a great lock-in feel and grip.
• You love trail aesthetics and you're looking for something stylish to wear every day, be it in town or away from it.

Forget about the Mountain Fly 2 Low if you are totally and absolutely done with break-in periods. The stiff structure of this Nike pair is not very welcoming, and your feet might end up dealing with uncomfortable rubbing. We've reviewed some other Nike sneakers that are comfortable from the very first time you put them on, so don't hesitate to have a look at our catalog!

Then, if you need something lightweight to wear all day long, this ain't it. There are many other sneakers from the Swoosh with a more nimble design. And last but not least, if you need something to really face Mother Nature on a more challenging adventure, let us introduce you to the trail running and the hiking shoes world.

Just by having a look at this shoe, you can probably guess it's gonna be pretty tall. That's how our feet felt during our wear tests, and when we took it to our lab, our caliper verified it, as it marked 35.5 mm. This score is higher than average, which means that your feet will be separated from the floor and shielded from any obstacles.

The forefoot stack of this Nike ACG reaches some crazy 25.6 mm. Trust us, we were just as open-mouthed as our caliper when it marked that! This score is way higher than average, and it meant that this shoe would protect us from any impact when walking and from harsh urban surfaces.

Once we had both the heel and the forefoot stacks, we could calculate the drop, which was 9.9 mm. After seeing how tall the toe area is, we weren't surprised at all. This result is standard, so there's nothing for you to worry about here! It'll feel like many of your other sneakers, be it the Adidas Gazelle or the Air Jordan 1 Low. After all, there are many casual pairs with this average drop.

After our wear tests, we can't say the Mountain Fly 2 Low feels super soft underfoot. Even though its tall bottom might make you think otherwise, our durometer marked 34.0 HA when we pressed it against the orange foam.

Between the two compounds we could find on this Nike ACG's midsole, this one is the hardest, as it's also the closest to the floor. Brands usually go for this design: a softer foam next to the foot to improve comfort levels, and a harder one underneath to offer better stability.

Confirming our hypothesis, our durometer returned 29.0 HA when we checked this shoe's secondary foam softness. Now this score is softer than average, and even though that means the Mountain Fly 2 Low feels nice underfoot, we just can't say it's plush! If that's what you're looking for, these are the sneakers with the softest midsoles we've reviewed.

Our feet rested over a 5.1 mm thick insole. Even though this score is just average, we found it comfortable and nice, so there's nothing else to say about it!

Even though shoes with a high stack are usually not very stable, this Nike ACG has a solid structure that keeps the brand's promise: the shoe is fast, rugged and ready for whatever wild comes your way. We confirmed it during our wear tests, as we felt safe and sound even if we walked through some parks with uneven terrain.

As we were saying, the Mountain Fly 2 Low features a solid structure that made us feel stable during our wear tests. We verified it in our lab, as it was impossible for our fingers to twist this brick of a shoe. Its rubber protections and tall lateral walls wouldn't let us mess with it, so we decided to give this Nike ACG a perfect 5/5 on our torsional rigidity test.

Luckily for us, its heel counter is not that stiff. As you can see in the video below, we were able to bend it and squeeze it with our fingers, so it earned a standard 3/5 on this test. It didn't hurt our Achilles tendon, which is something we really appreciated!

Nike was actually serious regarding stability when it comes to the Mountain Fly 2. After all, if you want to spend hours walking and go on adventures beyond the city, your shoes need to be ready! In this case, this Nike ACG features a really wide midsole in the forefoot that let our feet land comfortably, and we could splay our toes easily during our wear tests... no matter where we were!

At 119.8 mm, our caliper marked there's a lot of space! In fact, the Mountain Fly 2 comes second on midsole width in the forefoot to only the massive Adidas Ozweego and New Balance 9060 (both at 121.0 mm).

The midsole in the heel is also incredibly wide. At 99.4 mm, our caliper left us in awe, as there are not many other sneakers that offer all this space in the rearfoot. Once again, we were happy with this design, as it makes readjusting every step when you're walking on uneven terrain easier.

The solid structure of the Nike ACG is rigid torsionally and longitudinally. In our experience, this shoe needs some time to warm up before it starts following your feet moves more smoothly, so don't expect an easy ride from the very first minute.

As you can see, we needed 34.8N of force to make it bow all the way to 90 degrees. This is way more than average, and taking into account the score on our torsional rigidity test, you'll most likely need to overcome a break-in period before you can enjoy the Mountain Fly 2 Low's comfort to the fullest.

The main drawback we noticed on this Nike pair is its weight. During our wear tests, our legs ended up more tired than with many other sneakers we have tried up to this date. We understood why when we took the Mountain Fly 2 Low to our lab, as our scale returned 15.20 oz/431g, which is way higher than average. If you want to wear this beauty for hours and hours, expect tired muscles at the end of the day. As an alternative, you can always check the lightweight casual models that have the VIP pass to our lab.

Nike promises great breathability, and thanks to our first-hand experience wearing this shoe, we can confidently tell you it delivered.

As you can see, our light shone strongly through the Mountain Fly 2 Low's upper material. Even though we still need to verify it with our smoke machine and microscope, it's a sign of great ventilation, as it usually translates into fantastic airflow.

And that's exactly what happened! Look at all the smoke that comes out of the toebox area. This Nike ACG is ready for warm temperatures, and it'll also dry up pretty fast if you end up stepping on a puddle. The poor Reebok Phase Court, which scored a disappointing 1/5 on this same test, was totally overshadowed by the Mountain Fly 2 Low's performance. Consequently, we decided to give the latter a fantastic 4/5 on breathability.

Thanks to our microscope, we could see there are multiple gaps in the upper material. Even though there are 2 layers, the threads are wide open, which favors airflow and lets your feet breathe.

Our Dremel managed to dodge the impressively extended toe cap, but the final result was probably not what it was expecting. At 5K RPM and with 2N of force, the tool drilled this Nike ACG's upper non-stop, yet the damage was insignificant. If we could give this shoe a 6/5 on our toebox durability test, trust us, we would. But as our scale ends in 5/5, that's what it's getting!

Even though the heel lining is usually the weak spot of many shoes, the Mountain Fly 2 Low is here to tell you: "Maybe when pigs fly". Once again, at 5K RPM and with 2N of force, our Dremel attacked the back of this Nike non-stop for 4 seconds.

If we didn't have this video above, we also wouldn't believe there was a literal drill trying to destroy the shoe. The final result was so good that we couldn't give this Nike ACG any less than a perfect 5/5 on our heel padding durability test.

Our durometer returned 94.0 HC when we pressed it against this shoe's outsole. This result indicates the material is pretty hard, which usually translates into wonderful durability.

And it turns out that we were totally right with our hypothesis. We grabbed our Dremel one last time at 10K RPM and with 2N of force, and even though there was an orange sandstorm for 18 seconds, the material showed wonderful wear resistance.

Our tread gauge measured the depth of the damage, and it marked only 0.7 mm. This lower score proves the Mountain Fly 2 Low is ready to last, as the rubber it features at the bottom is way more durable than average.

Our caliper returned 6.5 mm when we measured this Nike ACG's outsole thickness. Even though we believe this might be a little bit too much if we take into account the durability of the material used, we can also see why the brand made this choice. After all, the shoe is called All Condition Wear, so it needs to be able to manage different types of terrain.

We believe that's the reason why Nike added those lugs. They are definitely necessary for trails, but this decision also comes with some extra weight... and it might not be worth it for some people.

The Mountain Fly 2 Low features a trail-like outsole with multiple lugs. These pieces are orientated in different positions to improve multidirectional grip, which is something we appreciated when we left urban surfaces behind.

After multiple hours wear testing this Nike ACG, we can tell you we're really happy with its traction. Its lugs bit the floor easily, and they're not too thick to be uncomfortable to walk around town. Nevertheless, if you're planning on going on a more serious adventure, we believe you'd be better off with a pair of hiking shoes.

If we mix the results and the data we've obtained from our wear and lab tests, we come to a clear conclusion: the Mountain Fly 2 Low is definitely a bang for the buck. For only $150, you get an incredibly versatile, durable, breathable, comfortable, and stylish pair of shoes that will be by your side for a long time. As long as you don't mind break-in periods or heavier footwear, this Nike ACG is a daily beater that comes with way more advantages than many other models in this same price range.

Some reflective accents would have just been the cherry on top for this pair, but ah well, you can't have it all!

Our caliper returned 10.1 mm when we measured this shoe's tongue padding. As you can see in the picture below, cutting the Mountain Fly 2 Low in half let us see that there's way more padding at the top of the tongue than in the area closer to the toes.

This means the brand focused on reinforcing the key areas, so in case you want to tighten the laces all the up and push the toggle, your instep will be protected. We can see this same philosophy throughout the whole upper, as only the heel area has a pillowy design. This doesn't just improve comfort, it also allows the shoe to be breathable.

The Mountain Fly 2 Low features a semi-gusseted tongue on both sides. Even though this also adds some weight, we find this design really convenient, as it prevents pebbles and dirt from getting into the shoe. This pair is designed to be your pal even if you leave the city behind and go on a more nature-friendly adventure, so of course its upper has to keep up!

The Mountain Fly 2 Low has a practical finger loop at the back. With its semi-gusseted tongue and snug fit, we found it really convenient to put the shoe on and off.

The Mountain Fly 2 Low features a removable insole, so you can change it easily if you want some extra space or if you just need to. Just bear in mind that if you opt for a plusher one, the snug fit of this Nike ACG might lead to discomfort because there will be less space for your feet.