It looks kind of weak, but is slightly decieving. They are not for snow trails, but in any other terrain they tread nicely. Even in the mud where a knobby sole works well, these seem to flush out the mud and keep the sole clean.

I've run several races in these on various types of terrain (mud, boulders, grass, and normal single track) and have found these shoes to grip better than other trail shoes I have run in (Brooks Cascadias, Pearl Izumis). La Sportiva calls the outer sole the "FriXion outsoles"... whatever that means. Regardless, the sole and treads do a great job of clinging to the trail.I feel like you have more control in this shoe compared to others... it feels like a lower profile. Hope this helps!Ditto and I concur with the above. These are good, solid trail runners. I have put what looks like non agressive tread to the test and it performed better than most. The Frixion rubber is a composite made from rock climbing sticky rubber. I've run through everything but deep mud and stayed glued to the trail. They come in wider sizes; look for the + next to the size number.No complaints but one, laces are a bit short, other than that these babies rock.