As a minimal shoe wearer, the release of Vivobarefoot’s new trail shoes was always going to be a big one for me. The Neo Trail, Breatho and Trail Freak, each an improvement on their predecessor, were all great trail shoes but they lacked durability, a secure fit and a proper off-road sole.

The Primus Trail firm (FG) and soft (SG) ground versions seek to overcome the traction issue and their shape is wider and flatter with a slightly thicker sole, yet still uniquely close to the ground. I’ve been wearing both for a year (see my separate review of the FG). The question then is whether they are worthy evolutions of VB’s off-road shoe design.


A mix of mesh bonded (rather than stitched) to plastic and rubber. Plastic is used around the toes and ecorubber for the midfoot with, on the SG, a stretchy ankle collar and integrated tongue.

The use of rubber and plastic to strengthen the mesh around the toebox works well and is durable. The rubber around the midfoot creates a secure fit and my foot does not slip around even when running through marsh and across slopes. The stretchy sock-like ankle collar is comfortable and secure and holds the shoe on through deep mud. If I sound surprised, it’s because during my first few runs, I found that the lightness of the upper was at odds with the weight of the sole and I had doubts about their abilities. This was exacerbated by the thin laces which extended too far towards the front of the foot for me and dug in when my foot flexed. I had to cut out the integrated laces and replace with normal laces, missing out the lowest lace loop on the outside and the second to last loop on the inside. This makes the shoe really comfortable for me and I’ve come to trust it more and more. It’s unusual for a shoe of this type to need ‘wearing in’ but it’s true of this shoe for me and a comment I have seen in another review.


The rubber sole is more of a cradle than a platform. It extends over the foot on all sides, moreso around the heel and big toe. The lugs face in opposing directions on the front and rear halves of the sole so that their open ‘V’ always faces towards the middle. Combined with variation in their size this provides great grip uphill, downhill and when contouring, comparable to off-road shoes by Inov8. This gives me confidence running on mud and uneven soft ground, including tussocks. In these tough running conditions no other shoe I’ve tried provides this level of proprioception (the sole is thin enough to provide good feedback) and proximity to the ground.

Unsurprisingly, the shoe is less useful on road and hard trail, as the lugs provide limited surface contact. On this type of terrain I find the shoe uncomfortable and the heaviness of the sole detrimental to running efficiency but, so what, VB provides the firm ground (FG) version for these runs (see my review).

Wear and Tear:

After one year and 100+ miles on grass and soft trail in all seasons, there is some damage to the mesh upper on the inside where the shoe flexes. This localised wear has no impact on performance.



A genuine minimal shoe that works best in wet or muddy off-road conditions. It provides unrivalled proprioception but the sole is heavier than ideal. Long-term test shows good durability. 88/100.


Weight – 250g
Midsole – None, so zero drop and no toe spring.
Outsole – Tough rubber with two-pronged lugs. Sole wraps round to form bumper.
Insole – standard and removable.
Fitting – Foot shaped with wide toebox. Runs true to size. Works with Correct Toes.


I purchased these shoes.


For other expert reviews on this and other shoes see