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Vivobarefoot Primus Trail II FG Review

More trendy than functional, these barefoot runners hit all of the talking points without necessarily delivering in terms of performance
Vivobarefoot Primus Trail II FG
Photo: Vivobarefoot
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Price:  $160 List | $160.00 at Amazon
Pros:  Naturally spacious, durable, versatile
Cons:  Expensive, stiff outsole, heavy
Manufacturer:   Vivobarefoot
By Aaron Rice ⋅ Review Editor  ⋅  Jul 23, 2021
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66
OVERALL
SCORE


RANKED
#7 of 8
  • Natural Feel - 40% 6
  • Weight - 20% 4
  • Traction - 15% 8
  • Versatility - 15% 9
  • Durability - 10% 8

Our Verdict

The Vivobarefoot Primus Trail II FG is an innovative barefoot trail runner, not necessarily in terms of performance but more in terms of manufacturing impact. The entire outer shoe — including the Firm Ground outsole (represented by "FG" in the naming scheme) — is made from recycled post-consumer plastic waste and is free from materials made with animal products, qualifying them as vegan. Oversized, 4mm lugs make up the majority of the 6.5mm stack height on this zero-drop shoe, providing ample traction whether you're taking them out for a run on the road or trail. While they are a tad heavier and less responsive than other barefoot options, they still provide for ample freedom of movement, particularly by offering one of the widest toe boxes available on the market.

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Awards  Editors' Choice Award Best Buy Award Top Pick Award Top Pick Award 
Price $160.00 at Amazon$124.99 at Amazon$80 List
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$120.00 at Amazon$119.95 at Amazon
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Pros Naturally spacious, durable, versatileSuper flexible, amazing feedback, spacious fit, breathable, optional insoleSuperlight, exceptional natural feel, flexible, affordableSuper low-profile sole, comfortably padded, designed for durabilityTough exterior, stable, snug lacing system
Cons Expensive, stiff outsole, heavyHeavier than most, potential durability issues, short lacesDiminished grip off-road, confining stretch collar, bulky lacesTapered toe box is a bit restrictive, traction is compromised by dirt, lack of versatilityOdd flex pattern, decreased sensitivity, lack of dexterity in toes
Bottom Line More trendy than functional, these barefoot runners hit all of the talking points without necessarily delivering in terms of performanceFrom its airy fit to its free range of motion, this barefoot shoe offers the best in lightweight running performanceA barefoot trainer that continues to define the category, this shoe’s ultra-thin outsole helps deliver superior natural feelAn incredibly thin outsole, supportive padding, and reinforced sidewalls make this an ideal barefoot gym trainerRun in comfort and confidence in this tank of a FiveFinger shoe
Rating Categories Vivobarefoot Primus... Xero Shoes HFS Merrell Vapor Glove 5 Inov-8 Bare-XF 210 V3 Vibram V-Trail 2.0
Natural Feel (40%)
6.0
9.0
8.0
8.0
7.0
Weight (20%)
4.0
6.0
8.0
7.0
7.0
Traction (15%)
8.0
7.0
6.0
6.0
8.0
Versatility (15%)
9.0
8.0
7.0
7.0
6.0
Durability (10%)
8.0
6.0
7.0
8.0
9.0
Specs Vivobarefoot Primus... Xero Shoes HFS Merrell Vapor Glove 5 Inov-8 Bare-XF 210 V3 Vibram V-Trail 2.0
Style Barefoot trail Barefoot road Barefoot road Barefoot road Barefoot trail
Weight (per shoe) 10.3 oz (size US 9) 7.9 oz (size US 9.5) 5.8 oz (size US 8.5) 6.8 oz (size US 9) 6.9 oz (size EU 42)
Stack Height 6.5 mm (w/o insole) 5.5 mm (w/o insole) 6.5 mm 1.5 mm (w/o insole) 5.7 mm
Heel to Toe drop 0 mm 0 mm 0 mm 0 mm 0 mm
Outsole 6.5 mm,
Firm Ground
5.5mm FeelTrue 2 mm, Vibram Ecostep 1.5 mm,
Inov-8 rubber
3.7 mm, Megagrip Rubber
Midsole None None None None 2 mm EVA
Insole 2 mm Bloom Performance (Ortholite) 3 mm High Density EVA Integrated
4 mm EVA
3 mm Power Footbed None
Upper Material Mesh, recycled materials Mesh and TPU Mesh and TPU Mesh and Rope-Tec TPU 3D Cocoon Mesh
Best For (running, gym, etc.) Running Running Running Gym Running
Width Options Regular Regular Regular Regular Regular

Our Analysis and Test Results

While the manufacturer claims that the insole of the Primus Trail II FG is part of their program in conjunction with Bloom Materials, it appears instead to be an Ortholite Recycled insole. Perhaps the coolest part in terms of direct impact is Vivobarefoot's Revivo program, which helps keep shoes out of the landfill by opening up a repair and reconditioning program for used shoes.

Performance Comparison


Rugged, stylish, and functional, the Vivobarefoot Primus Trail II FG...
Rugged, stylish, and functional, the Vivobarefoot Primus Trail II FG provides solid structure with a barefoot feeling.
Photo: Jill Rice

Natural Feel


Vivobarefoot is one of the original companies to produce barefoot running shoes, and the Primus Trail II FG builds on that tradition with a trail-specific twist. The overall design is simple and lightweight, with a thin, flexible upper made with a majority of mesh for a naturally lightweight feeling and improved breathability. A minimal stack height of 6.5mm and zero-drop creates a perfectly flat platform without conventional support. An oversized fit with a spacious toe box makes these the ideal barefoot shoe for those with particularly wide feet.

These barefoot runners provide plenty of protection, while keeping...
These barefoot runners provide plenty of protection, while keeping your soles close to the ground.
Photo: Jill Rice

Though all signs from the upper point to a high degree of natural feeling, the "Firm Ground" outsole — specifically designed for technical trail running — greatly reduces feedback. Though the outsole is thin, the hard rubber doesn't allow for much ground-feel, and the hardness of the rubber also reduces outsole flexibility. Even though this shoe feels flexible both longitudinally and torsionally in your hands, this doesn't translate to our experience when running. Instead of flexing along the natural lines of your foot and conforming to the terrain, the thicker outsole slaps the ground, leaving you with this feeling of being disconnected — kind of like wearing a glove rather than gripping something with your bare hands.

A stiff outsole provides plenty of grip for off-trail adventure, but...
A stiff outsole provides plenty of grip for off-trail adventure, but slightly works against the natural feel of this shoe.
Photo: Jill Rice

Weight


The Primus Trail II FG is surprisingly heavy, despite the simplistic design. Although they stand at a very reasonable stack height for a barefoot runner, all of the 6.5mm is concentrated in the hard rubber of the Firm Ground outsole. Additionally, to improve its durability as a trail runner, the design incorporates a lot of a recycled, TPU-like material to reinforce the mesh upper — the medial sidewall is almost completely covered in this material.

The robust upper and hard rubber outsole contribute to the weight of...
The robust upper and hard rubber outsole contribute to the weight of the Vivobarefoot Primus Trail II FG. While it is strong, it is not light compared to the rest of the pack.
Photo: Jill Rice

If you're really concerned about shaving weight in these shoes, the removable insoles do weigh 0.9-ounces each. Fortunately, all of this extra material doesn't much affect the swing weight, but it does continue to affect the natural feel of this shoe. Rather than feeling integrated with your foot, the Primus Trail II FG almost feels like a protective shell.

Recycled, removeable outsoles can come in and out to tweak comfort...
Recycled, removeable outsoles can come in and out to tweak comfort levels, and shave ounces if you are worried about the additional swing weight.
Photo: Jill Rice

Traction


While it may not flex with the contours of your foot and the terrain, the Primus Trail II FG is well-designed to propel you through your run. Designed as a trail-specific shoe, the thick 4mm lugs hold well on both rocky and loose terrain. A textured arch is a unique design feature: while many shoes opt to leave this spot on the outsole blank, this rubberized section on the Primus Trail continues to grip even when you get off-camber on more technical trails.

The hard-rubber outsole provides more than enough protection against...
The hard-rubber outsole provides more than enough protection against rocks and roots, and the textured arch helps your propel through off-camber foot placements.
Photo: Jill Rice

Versatility


Don't be fooled by their name; this shoe transitions remarkably well between trail and road. While the outsole isn't particularly tacky, the homogeneous lug shape provides an even platform to comfortably cover miles of pavement. This crossover capacity was unexpected and is quite a nice surprise gift, particularly considering the price tag of these barefoot runners. Despite the oversized lugs and thicker stack height — at least compared relatively to other barefoot options — the Primus Trail II FG is still a bit too minimal to be considered an introductory shoe for those looking to transition to this style of footwear. Regardless of your athletic background, they do make for a comfortable gym shoe. The flat platform, wide toe box, stiff outsole, and breathable upper all make for a sturdy, comfortable, minimalist trainer.

The wide toe box, zero-drop platform, and tacky lugs are appreciated...
The wide toe box, zero-drop platform, and tacky lugs are appreciated when throwing around heavy kettlebells in the gym.
Photo: Jill Rice

Durability


Though there is a stigma surrounding the durability of post-consumer recycled materials, the sturdy construction of the Primus Trail II FG should help dismantle any of your preconceived notions. After our testing period, the outsoles showed very little sign of wear and tear; considering the hardness of the rubber compound, we cannot imagine the outsole wearing very quickly. Specifically appreciated by trail runners — though applicable to anyone liable to toe-drag — the entire front of the tox box has a protective wrap of ripstop and TPU-like rubber. And even though it may add unnecessary ounces, most of the upper is reinforced with panels and cross braces of recycled rubber.

A significant amount of TPU-like material on the upper might add a...
A significant amount of TPU-like material on the upper might add a few ounces, but it definitely improves durability, ideal for off-trail travel.
Photo: Jill Rice

Value


While closing the loop on manufacturing processes and shortening supply chains ultimately reduces impact, this is certainly not the norm when compared to current standards of conventional production. Though this results in more expensive products for now, companies producing according to standards set by B Corp are at least striving to create positive change within their industries. The price of the Primus Trail II FG is higher than others, but the production of this shoe is also being held to a higher ethical standard.

Conclusion


The Vivobarefoot Primus Trail II FG is a solid, ethically-built barefoot runner that excels in a cross-training capacity. Though it has some technical design flaws and doesn't quite live up to the natural feedback of other barefoot shoes, it is a strong contender among trail-specific shoes and should be particularly appealing to those with wide feet.

Over roads and trails, the Vivobarefoot Primus Trail II FG is one of...
Over roads and trails, the Vivobarefoot Primus Trail II FG is one of the most versatile barefoot trainers we tested.
Photo: Jill Rice

Aaron Rice