Aku Alterra II Gtx Review

The Alterra II Gtx from Aku presents itself as a versatile hiking boot for medium to long distances. It is a shoe that fits into the broad segment of hiking at medium-high altitudes, on terrain of difficulty E and occasionally EE, on various types of terrain: from the classic trail to scree and scree slopes.

Technical features of the Aku Alterra II Gtx

• Upper: 1.6 mm suede + stretch fabric
• Upper protection: liba smart pu
• Lining: Gore-Tex More Seasons
• Tread: Vibram Alterra II with dual density wedge
• Midsole: pu + eva
• Midsole: 6-4 mm nylon + microporous
• Footbed: custom fit soft
• Men’s weight (gr. ½ pair n 42): 655
• Manufacturer country: Romania
• Link to the manufacturer

Test mode

I had the opportunity to test the Alterra II Gtx during the spring and summer of this year, mostly on day trips on routes of difficulty E or EE, with some equipped passages or short sections of basic climbing. The excursions took place on routes with a positive altitude difference of between 1000 and 1900 m, at an altitude of between 1100 and 2600 m.

In addition, in order to test their behaviour over long distances and on multi-day treks, I walked part of the Translagorai, where I encountered many boulders and scree.

I walked mainly in sunny weather, even on hot and muggy days, and on a couple of occasions I walked in light rain.

Aku Alterra II Gtx on-site test

First impressions

The Alterra II Gtx at first impact gives the idea of a robust and durable boot. It manages to convey confidence even before you put it on. Moreover, once it is in your hand, the low weight is a positive surprise.

Personally, I find the brown colour choice of the suede upper, which is also available in anthracite and orange, pleasing.

Comfort and fit of the Aku Alterra II Gtx

As I have a rather wide footbed and a pronounced medial arch, I often face an initial sense of discomfort with many shoes. To my surprise, however, I found the Alterra II Gtx comfortable right from the start, something that I rarely experience with other shoes.

Merit certainly goes to the construction of the Nylon insole and the custom fit soft insole, which give support to the foot by distributing pressure evenly over the sole.

The upper is suede, with PU reinforcements in the lower part, where most stresses and impacts with rock occur.

The knee-high, on the other hand, has been lightened with a honeycomb weave that makes it less rigid without compromising stability. This structure allows the ankle to flex naturally depending on the terrain, while still providing support and protecting against sprains.

The elasticised tongue with Gore-tex membrane wraps around the foot and ankle, creating a ‘fit sock’ fit.

Lacing system

The lacing system is the boot’s real strength. At the bottom, the laces pass through pulleys, placed asymmetrically between the inner and outer lines of the loops. This system guarantees a very snug closure of the forefoot and midfoot.

Dividing the lower from the upper part of the foot are two blocking loops, which allow the two areas to be adjusted differently, tightening the laces with different intensity.

In fact, this closure system allows the boot to be customised according to the trekker’s needs and habits.

Walking behaviour of the Aku Alterra II Gtx

During the walk, I really appreciated the comfort of the boot, which proved capable of adapting to the foot from the very first outing.

This feeling of comfort is linked to the adoption of the Elica system, which we have also become familiar with in other Aku brand products.

This particular composition of midsole and Sole facilitates walking, accompanying the roll of the foot. The external heel area, in fact, is reinforced and slightly inclined outwards to better cushion the impact on the ground. During forefoot thrust, on the other hand, the reinforced part is the inner one to guarantee greater grip, stability and at the same time greater protection for the foot.

The PU and EVA midsole effectively cushions impacts with the ground, even the most uneven, as I tested on the stone paths of the Lagorai.

The Vibram Sole with a well-marked and pronounced tread pattern guarantees grip on all types of terrain, from wet grassland to wet rocks or scree trails.

Behaviour on rock

The Alterra IIs also perform reasonably well on short equipped or simple climbing passages that I tackled during the test.

However, these are not boots designed for mountaineering routes or long via ferratas. The lack of a real climbing zone, and the same propeller system that is so effective in walking, reduce the precision of support in rock passages.

Moreover, the Aku Alterra IIs have a structure and rigidity that do not even make them suitable for use with crampons, except on short snowfields using buckled universal crampons.

In terms of protection, the well-structured upper and PU side and front inserts protect the foot from rock impacts. In addition, the Vibram Weave Technology tread has a two-density polyurethane and EVA wedge to cushion the most uneven and angular surfaces.

Even on the uneven trails of the Lagorai I had no problems.

Waterproofness, thermal comfort and protection

Underneath the suede upper we find a Gore-tex membrane that makes the boot waterproof . On first contact with water, the colour change of the upper puzzled me, but I must say that my feet always remained dry despite walking for several hours in dew-soaked meadows.

I have also had to wade through torrents with the water exceeding the lower loops of the boot. In these cases, I have found that not only does the upper effectively resist water, but also the tongue does not let anything through.

Furthermore, the drying of the upper is very quick.

With regard to thermal comfort and breathability , I tested the Alterra II Gtx at two different times of the year: spring and summer.

During the spring trekking and during the rainy month of June, I found the boots fully adequate in terms of thermal insulation; the feet were warm and dry.

During the sultry months of July and August, however, I suffered more and my foot was often damp and sweaty at the end of the day. On hot days the breathability has some limitations.

Fitting of the Aku Alterra II Gtx

I tested the Aku Alterra II Gtx in size 43 EU, which is half a size bigger than my usual size.

During testing, I felt very comfortable as I felt neither pressure on the toe when descending nor slippage when ascending.

Recommended for

I recommend the Aku Alterra II to those who are looking for a solid and durable boot that will protect the foot during day hikes at medium-high altitudes, even over long distances and over impassable terrain.

They are also suitable for theadvanced hiker who undertakes multi-day traverses with significant development, elevation gain and weight on their shoulders, where it is important to have stability and protection from the terrain and weather.

The closure system with two adjustment zones (high and low) allows the boot to be customised to the wearer’s needs, making it suitable even for those who, like me, struggle to find a boot that fits their foot.

They are not suitable for low altitudes or very hot temperatures, as well as snowy or alpine terrain.