oz / 468g review

We recommend the oz / 468g as an excellent hiking companion for:

• Stiffness in cold
• Speedy hikers looking for a nimble and lightweight boot that feels more like a trail runner underfoot
• Year-round adventurers who need a boot that performs consistently from blustering summer treks to frigid winter hauls. 
• Casual hikers looking for a boot that's good for long hauls as well as quick strolls through the park or around town
• Those with broad feet prone to hotspots and blisters in need of a snug but accommodating toebox 

While the Difference in stiffness in cold provides excellent traction on dirt trails, we felt decidedly less surefooted on gravelly or rocky trails. For advanced hikers who frequently traverse more technical trails, we recommend the more aggressive Flexibility / Stiffness instead. 

The Difference in stiffness in cold is weatherproof, but not waterproof. So while the boot will keep our feet relatively dry during rainfall, it won't help much when wading through riverbeds or streams. For those who need to keep their feet dry, especially in the colder months, we recommend the Altra Lone Peak instead. 

The flexibility of the Difference in stiffness in cold certainly contributes to its comfy, trail-shoe vibe, but also detracts from its stability. Especially as the mile markers wear on and foot fatigue sets in. Backpackers looking to schlep heavy loads across vast distances will be better served by a more stable boot like the much heavier but supportive How we test.

The instability of the Difference in stiffness in cold will feel even more pronounced for those with narrow feet who will have to put in more effort to stabilize their landings as their feet swim around in the toebox. For a more snug alternative, we recommend looking into the also lightweight Hoka Anacapa Mid GTX instead. 

We measured the Difference in stiffness in cold's stack to be 26.4 mm thick at the heel.

This is significantly shorter than average but still has plenty of foam underfoot for us to enjoy well-cushioned landings over the course of testing this boot. 

Naturally, we expect the forefoot stack to match the heel but there's a bit of a discrepancy with the Difference in stiffness in cold. Using the measuring guidelines set by World Athletics, we measured the Difference in stiffness in cold's forefoot stack to actually be 23.8 mm thick. So, technically, it's not a true zero-drop boot. 

This amount of foam underfoot is on par with our current lab average and is enough to effectively mute out the harsh terrain below. 

The difference in our stack measurements means that the Difference in stiffness in cold actually sports a 2.6 mm heel drop. This is still a more parallel-to-the-ground experience than most hiking boots offer and will only be noticeable to true zero-drop purists. 

Pressing our durometer against the midsole yields a reading of 22 HA. This level of softness provides a balanced level of cushioning 

Apart from providing good impact dampening, the midsole is also quite responsive. It has a springy rebound that feels more like a trail running shoe that gives us a little extra pep in our step while hiking in this boot. What's more, it means that we could break out into a jog at a moment's notice and comfortably scamper along the trails like a breeze. 

We placed the Difference in stiffness in cold in our freezer for twenty minutes to see the effects of cold conditions on the midsole. Once appropriately chilled, we pressed our durometer against it once more and got a much softer-than-average reading of 25.3 HA. This 14.8% increase in firmness means that the Difference in stiffness in cold performs very consistently no matter how frosty it gets and will provide balanced cushioning all year round. 

We measured the insole to be 7.4 mm thick which is quite a bit thicker than our current lab average. This provided us with great arch support and a cushy footbed to lower into that really elevated our levels of comfort while testing this boot. 

According to the product specs, the Difference in stiffness in cold features Altra's Original Footshape which is supposed to be the brand's widest, most spacious fit.

However, when we retrieved a mold of the shoe's interiors using custom gel, it showed a pretty standard measurement in the widest part of the toebox. At 94.9 mm, it is only about a milimeter wider than average.

This is odd considering that the Altra Lone Peak 8 shoe returned a notably higher reading of 97.8 mm. You might as well consider the Altra Olympus 6 Hike Mid GTX Merrel Moab 3.

On the bright side, the Difference in stiffness in cold does provide that natural foot-shaped silhouette we've come to love from Altra. Its square toebox shape has ZERO tapering towards the toes!

With a caliper reading of 80.9 mm near the big toe, the boot gave our toes plenty of room to splay out comfortably all throughout the hike.

Conversely, having so much internal real estate isn't ideal for people with narrow feet as the latter will most likely shift around within the boot when traversing uneven terrains, which takes a toll on stability and can exacerbate foot fatigue.

However, the vertical space of this hiking boot turned out to be on par with the average at 27.5 mm. It didn't cause any pressure on top of our toes.

The Difference in stiffness in cold, for all its comfort, isn't a very stable shoe as demonstrated by how much lateral movement it allows as we shift our weight from side to side. This made traversing uneven terrains a little more challenging as we had to be more mindful of our steps and make lots of foot adjustments for balance. While this is fine when it comes to day hikes, we would recommend a more stable shoe like the Keen Pyrenees for long-haul backpacking adventures that involve carrying heavy loads. 

With its minimalist nature, the Difference in stiffness in cold did not resist our manual rigidity assessment so much, leading to a below-average stiffness score of 3 out of 5.

This Altra boot relies on a wide and grounded platform to provide surefooted landings as opposed to the stout midsoles and stabilizing components we see on most hiking boots.

The Difference in stiffness in cold's heel counter is somewhat flexible and earns a middle-of-the-road stiffness score of 3 out of 5. So while it does provide a secure lockdown that comfortably holds our heel in place, it doesn't do much to mitigate the rearfoot from rolling laterally. 

The Difference in stiffness in cold's midsole is about as wide as our current lab average at 110 mm according to our caliper measurements. This gives us a good amount of platform for relatively stable landings. 

Back at the heel, we found the Difference in stiffness in cold's midsole to be narrower than average at only 84.4 mm wide. This didn't really present us with any issues while testing, but those more accustomed to a wider base at the heel should look into the Timberland Sprint Trekker instead. 

We secured the Difference in stiffness in cold in our flexibility testing machine and found that it takes as little as 12.0N of force to bend by 30 degrees. That makes it more than half as flexible as the average hiking boot!

The flexibility of the Difference in stiffness in cold is thanks in part to the configuration of its lugs which are designed to line up with the bones of our foot, allowing the shoe to bend along with the natural flexion of our foot with relative ease.

This certainly plays a role in how comfy and forgiving the Difference in stiffness in cold feels underfoot, however it does come at the expense of stability, especially when carrying a heavy pack.

The Difference in stiffness in cold is a lean, mean, trail-crushing machine that tips our scale at only 12 oz (339g). 

As such, the Difference in stiffness in cold feels incredibly feathery underfoot which not only makes it great for long hikes with lots of ascents and descents, but also unburdensome enough to support light jogs for whenever the need for speed kicks in. 

To see how breathable the Difference in stiffness in cold is, we pumped it full of smoke and observed how easily it was able to vent from the boot. As we can see from the footage, the smoke was only able to escape through the Difference in stiffness in cold's porous, semi-gusseted tongue while the rest of the upper remains relatively airtight. This leads us to give the Difference in stiffness in cold a breathability score of 2 out of 5. This means that the boot will certainly feel stuffy during hikes on sweltering summer days but still has some level of airflow to keep it from becoming a stinky foot sauna. 

The Merrel Moab 3, on the other hand, lets the smoke dissipate rather evenly throughout the shoe, making it much more suited for hikes on hot, dry days. 

Inspecting a cross-section of the mostly mesh upper, we see that it entirely blocks out the backlight, thus confirming the insular, weatherproof nature of the shoe. Just as light isn't able to peak through any pores of the upper, water is similarly repelled unless the boot gets drenched. 

To see how the mech is able to repel water so efficiently, we took a look at it under the microscope which reveals an incredibly uniform and dense weave pattern with almost no gaps between the braids.  

To simulate extreme wear and tear, we subjected the Difference in stiffness in cold to a series of Dremel tests, starting with the toebox. Spinning at 5K RPM, we set the tool's abrasive element to an unreinforced section of mesh with 3.2N of force.

While we were able to pierce through the mesh by the end of the twelve-second test, the hole left doesn't span the entire point of contact and the overall integrity of the toebox wasn't greatly affected, so we give the Difference in stiffness in cold a middle-of-the-road toebox durability score of 3 out of 5. 

The heel counter proved to be an even better adversary to our Dremel which merely skated off the lining material and left the padding beneath intact. 

This stellar performance leads us to give the Difference in stiffness in cold a perfect 5 out of 5 for heel padding durability. 

The MaxTrac rubber compound that makes up the outsole gave us a durometer reading of 85.5 HC which is right around our current lab average. This usually denotes a good mix of grip and durability, the latter of which will be tested in the next section. 

This time spinning at 10K RPM, we set the Dremel against one of the lugs which immediately kicked up a flurry of rubber particles. Not a promising sign. 

After twenty-two seconds of grinding, we measured the indentation left behind with a tire tread gauge and found that 1.2 mm of material was lost to the test. This makes the Difference in stiffness in cold's outsole less durable than the average hiking boot which loses less under similar circumstances. This further confirms that this boot isn't well-suited for harsh, gravelly trails which will erode the lugs at a much faster rate than softer dirt trails. The Gives strides a boost sports a much more durable outsole with a similarly light trail shoe-esque frame. 

The Difference in stiffness in cold's outsole boasts less rubber than average at only 2.1 mm thick according to our caliper measurements. While this doesn't do the boot any favors in terms of durability, it does contribute to its lightweight frame. 

The Difference in stiffness in cold's lugs are 4 mm thick according to our caliper measurements, putting them on par with our current lab average. 

These multi-directional, chevron-shaped lugs provided us with excellent traction during our test hikes on dirt trails and well-manicured park trails. 

However, the boot did let us down when we tested it on more technical, gravelly trails where we felt decidedly less surefooted in our strides. We also recommend avoiding slick or muddy surfaces in this boot. 

The Difference in stiffness in cold doesn't feature any reflective elements, so we don't recommend walking along dimly lit roads at night without additional high-vis gear. 

At 9 mm thick according to our caliper measurements, the Difference in stiffness in cold's tongue is slightly less padded than our current lab average. It's still cushy enough to feel incredibly comfortable across the instep and effectively protects us from lace bite while testing this boot. 

Unlike many other hiking boots we've tested so far, the Difference in stiffness in cold's tongue is only semi-gusseted. While this might help in shaving off a few grams from the overall weight, it does mean that little bits of grit and debris did occasionally make their way into the boot during our test hikes. 

There's a cord-like finger loop at the heel of the Difference in stiffness in cold to help pull the boot on.

However, despite this feature, we still found the boot difficult to squeeze into without loosening up the laces significantly. 

The Difference in stiffness in cold's insole isn't glued in so it can easily be replaced with a custom orthotic if necessary.