Security of fit
In its relatively brief history, Topo Athletic has nailed fit exceedingly well. The Oterro’s upper follows the natural shape of the foot, cinches down securely in the midfoot, and allows plenty of room for toes to spread naturally without feeling excessively wide in the front. The shoes come with a speed lace system, but traditional laces are also included; in our testing, the traditional lace system provides a more secure fit. However, be warned: cutting is the only way to change the speed laces, so once that’s done, there’s no going back.

Stability on impact
Grip and traction are outstanding with aggressive 4.5mm lugs that shed mud easily and hold on to technical terrain securely. The low stack height and almost-flat platform help with foot stability on sketchy surfaces as well.

Smoothness (flexibility)
The Oterro has full flexibility in all directions, allowing natural movement from heel to toe. The midsole compound isn’t highly responsive while running, but provides a great combination of ground feel and comfort for hiking.

Comfort
Lightweight padding in the Achilles area keeps the heel comfortable and stable, and thin lightweight mesh uppers ventilate well and dry quickly. The anatomic toe box prevents any rubbing or chafing. In our testing, the Oterro was worn on a 14-hour trail day without leaving any hot spots or irritation.

Speed and agility
The stable platform and aggressive grip make the Oterro fairly nimble for trail running, but the shoe’s true calling seems better suited for longer, slower trail explorations or multi-day outings.