Mammut Mercury GTX 2011

Mammut has a wide range of footwear products that extend from cross-trainers for multi-activity sports to full mountaineering boots for Himalayan climbs. The new Light Hiking range places the Mercury as its flagship product, thanks to its incredibly low weight coupled with springy underfoot cushioning and a striking design.

The Mammut Mercury GTX is an eye-catching boot that is slightly more enticing than the traditional brown leather products here. It features a tongue made from a black synthetic soft shell material plus a grey rather than brown leather upper with some raised trim, giving a modern look. The upper is quite soft, making this very comfy straight from the box, while the additional stiffening at the toe box and heel cup helps to protect and support the foot on rockier ground. Like some other lightweight models, the ankle cuff is lower than on a standard 3-season boot, so it offers less protection. Underfoot there is a Vibram sole with a Mammut Frog Grip concept, which is based on hexagonal studs. As well as protruding studs, there are sunken hexagonal holes, which – when I used the boot – rapidly clogged with mud, so I am not convinced they offer any benefit. But the most noticeable feature is the incredibly thick and spongy layer of cushioning at the heel, which gives this boot a uniquely bouncy feel almost resembling a road running shoe.

On the hill
The Mammut Mercury GTX are very comfortable as soon as you put them on, and when walking along a road that wedge of cushioning under the heel removes any jarring. They also provide a wide platform on every step, which feels great. But for me the cushioning is just a little too much, particularly under the heel, as I found that this amount of padding created a rather unstable heel strike and I preferred the more positive impact of other boots. The outsole is unusual due to the hexagonal holes. I did manage to clog these with mud on grassy slopes while descending, and hence lost a bit of grip. The hexagonal lugs are relatively shallow too, so they don’t grip that well either and will probably wear down sooner than deeper studs. As there’s no heel breast, I did not feel as confident on muddy or soft grass slopes in these boots as in other designs. But they are very comfortable on level ground, and thanks to that cushioning they can handle a traverse of rockier ground pretty well too.

Upper nubuck leather, synthetic tongue, Gore-Tex waterproof lining
Sole Vibram HLX, EVA cushioning
Sizes 6½-13
Weight 1060g (pair, size 46)
Made in China
Stores in the UK 10
Stockist details (01625) 508218;

The Mammut Mercury GTX has a good, stable platform on every step; extremely well-cushioned, particularly at the heel; very lightweight; modern styling. But the outsole not the best for grip in muddy terrain; the cushioning meant these were relatively unstable on heel strike and felt too cushioned for me. Overal, it’s a lightweight boot for walking on level, rocky paths as the grip is less impressive on muddy slopes while the cushioning may be too much for some.

Review by Graham Thompson
First published in Trail magazine July 2011