The Mammut T Aenergy GTX boots

Mammut T Aenergy GTX boots
Price: £160
Weight: 1,220g a pair (size 43.5)
Materials: upper, polyamide with liquid rubber protection; midsole, EVA; outsole: rubber
Waterproofing: Gore-Tex Performance Comfort membrane
Colour: graphite/inferno (grey/red)
Country of manufacture: China
Crampon rating: B0 (not crampon compatible)

grough rating:
Performance 30/35
Comfort 31/35
Quality 7/10
Value for money 14/20
Total score: 82/100

The oddly named T Aenergy GTX boots are lightweight offerings from the Swiss brand Mammut.

They’re a good looking, thoroughly modern model that uses a mixture of fabrics and rubber to keep weight low.

Our size 43½s (9½) tipped the scales at 1,220g for the pair, which pitches them into that crowded lightweight but not ultra-lightweight category. The Mammuts are priced accordingly too, at a similar level to other quality brands producing similar boots.

The boots have bright red sections on the scaly anteater soles

There were some lurid green models about recently, but Mammut supplied grough with a more subtly shaded grey pair, with nice bright red detailing, not least on the Vibram Scale sole, which has two large red sections too, the edges of which show on the outside of the sole, matching red in the midsole and uppers.

Mammut said the sole’s pattern is modelled on the scaly armour of the pangolin, or scaly anteater!

Its lugs are fairly tightly spaced and have aggressive ridged sections in the middle of the forefoot and heel sections. The sole is fairly flexible, both laterally and longitudinally and Mammut said the Rolling Concept shape of the sole allows for a natural foot roll when walking and prevents strain on the ankle.

The company, which used to market its boots under the Raichle brand, uses a flexibility index for its boots, from A4 to A9, at which point flexible crampons can be used. The T Aenergy GTX is rated at A8 which means it has reasonable damping while retaining the stiffness for some harder terrain.

The boot is modelled on the company’s hiking last and is ideal for backpacking and walking, it said, and is also suitable for mountain walking and travel.

The EVA midsole absorbs impact well and helps make the boots comfortable over longer distances

The midsole has an EVA wedge to absorb shocks, though the SDC footbed in the boot is a fairly basic affair with a lattice cushioning on the bottom but no apparent extra padding on high-impact areas such as the heel and ball of the foot.

There is a tough rubber toe box and the outsole also extends upwards over a section of the toe to offer additional protection and grip.

The uppers are a combination of tough-feeling polyamide (ie nylon) material and rubbery-plastic sections. The bottom part of the fabric is treated with Mammut’s Liquid Rubber Protection and the Base Fit lacing system uses a combination of fabric and metal loops anchored towards the sole by the extended rubber upper trim.

The fifth lace loop is set well back to prevent heel lift

The laces flow freely through the bottom four loops and the fifth is a sturdier metal and fabric loop set much further back and in line with the bottom of the Achilles’ area to direct force to the top of the heel box to prevent heel lift when walking.
Unfortunately, neither this nor the top two hooks lock the laces in place, which means they can only be correctly tightened by putting in a knot at the appropriate place to allow separate tension on the forefoot and ankle.

The top of the tongue and the ankle cuff both have Memo Foam for added comfort and it is clear the boot has been designed with walkers’ comfort high on the list of priorities.

In use, the T Aenergy GTX showed good traction uphill on our test route, which includes sections of gravel path, rocky path, mud, grass and a little scrambly section over both limestone and gritstone.

Uphill, the boots coped well on muddy sections, wet grass and mixed terrain. On hard sections, there was good cushioning, a sign the midsole absorption works well.

After extended use on walks, there was no sign of fatigue on the soles of the feet and the boots in general are comfortable in use.

Our main problem was in getting a satisfactory lacing setup. The laces are quite thin and, as mentioned above, there is no locking hook, so a knot is necessary to hold the forefoot firmly and stop heel lift or the foot slipping forward in the boot.

The Mammut T Aenergy GTX boots performed well in the wet

Overtightening the T Aenergy GTX at the fifth key lace loop put too much pressure on the ankle bone, so readjustment was necessary to get the tensioning right.

Braking downhill on all terrain types was good, with the exception of wet limestone, which has defeated all the boots we’ve tested. Only the super-sticky soles of lightweight fellrunning shoes have given us anything like confidence on this type of stone.

On a thoroughly wet outing involving heavy all-day rain and swollen streams, with paths running with water, the T Aenergy GTX kept out the rain.

As with all fabric boots, we recommend care in, for instance, keeping toenails neat, as the Gore-Tex liner is all that’s ultimately keeping out the rain.

And try on a pair of boots before you decide. Everyone’s foot shape is different and some brands and lasts will suit one person but not another.

These Mammuts performed well, were light enough not to tire out the wearer after extended wear and gave good support on mixed terrain.

Mammut's trademark pachyderm adorns the heel of the T Aenergy GTX boots

The Swiss brand says the T Aenergy GTX is ideal for backpacking and walking (obviously) and suitable for mountain walking.

We’d say the boots are fine for hillwalking on paths and reasonably difficult terrain though they’re unlikely to stand up to prolonged abuse on scree or rocky terrain where the uppers could be damaged.

The T Aenergy GTX is a stylish, lightweight boot that will perform well for anyone who wants an all-rounder capable of forays into the uplands.

More details are on the Mammut website.