This shoe features a Firm Ground Outsole to give you maximum grip plus improved resistance to abrasion. Because of this excellent outsole, you should be safe on any type of terrain; the sticky rubber on the bottom gives you great traction. The sole is durable
, made of tough material, and it has chevron lugs that help to provide its trademark traction. The sole is 7mm thick—just thick enough to protect you when running on various types of terrain, and definitely small enough to still provide you with a good ground feel, which is what all barefoot runners want.
The midsole construction in the Primus Trail FG is a bit different than you might expect. The inner part of the rubber outsole actually works as the main underfoot platform. This is to get you as close to the ground as possible—the shoe heavily accommodates runners who have a neutral gait and, again, minimalist runners. The midsole is both supportive and responsive. There is a supportive 3mm vegan insole that gives you some extra comfort and warmth, or if you want more ground feel, you can take it out.
system is a quick-release system (Mountain Lace with Toggle, described as being quick to secure and long to last) and is very efficient, which adds a nice touch to the upper. The upper is also very breathable because of the synthetic mesh material it is covered with. The Quick Drain Zones are located here too—these give the Primus Trail FG a superb drainage system and prevent water from pooling if you’re running in wet conditions. Fused Upper Material produces a smooth feel against the skin, and the minimal construction boosts the comfort aspect of the upper. Although the upper—especially the lacing system—is not very durable, it is comfortable and extremely breathable
The Primus Trail FG weighs 8.8 oz. Having a lightweight shoe is important for any runner, but perhaps especially so for barefoot runners—so you can be happy that the FG is sufficiently lightweight for all of your running needs.
The most breathable part of the Vivobarefoot Primus Trail FG is certainly the upper—it features a mesh material that circulates air well to keep your foot cool and dry. The breathability of the upper couldn’t be better, and it will keep everything cool and prevent you from getting blisters. The Quick Drain Zones, which give the shoe excellent drainage and prevent water from pooling, also help with breathability: they wick away perspiration and moisture through their semi-transparent panels on the side of the shoe. The FG is very breathable all over the shoe.
The upper is comfortable because of its minimal construction and the seamless Fused Upper Material—eliminating seams and using a smooth material ups the level of comfort. The wide toe box is comfortable as well. Soft textile lining and a thin foam insole add extra padding. Not one previous reviewer has reported getting blisters from the Primus Trail FG. The only times this shoe might be uncomfortable for any reason is if you are running in the cold (the upper is very thin) or if you are running on rocks—yes, this is a shoe meant for trail running, but the thin sole still won’t offer much protection against sharp rocks. If you are on less intense terrain, the FG will be very comfortable, but otherwise, you may find something lacking.
Both the men’s and women’s shoe come in black/charcoal, and in cordovan (a dark red color with a gray outsole and laces). The women’s Primus Trail FG also comes in an additional third color: cobblestone, which is a mix of a dull pink/purple/gray with a few muted coral accents. If you prefer something a little brighter and more colorful
for your barefoot running shoe, you will be out of luck here. The Primus Trail FG has a simple, streamlined look and muted colors. Despite the lack of color options—which isn’t necessarily a downfall, as many runners are tired of the constant parade of neon that makes up many running shoes—the FG is an aesthetically pleasing shoe.
The Primus Trail FG is a high-quality shoe. The sole is puncture-resistant, helping to add to the durability of the overall shoe. The outsole thickness is 7mm, which is thick enough to be durable but still thin enough to drive home the point that this is indeed a barefoot running shoe. A no-sew construction ensures seam durability. It has been reported that the only part of the shoe that is not durable are the laces—several users have mentioned that the laces were not high quality at all and broke down after only a few uses. The Mountain Lace with Toggle system is great in theory—you are supposed to be able to adjust it on the fly—but evidently, it is very delicate, so it won’t do you any good if it breaks down after only the first few times you have worn the shoe.
For the most part, the Primus Trail FG has good protection. The outsole is 7mm thick, and is puncture-resistant; reviewers have reported, though, that the sole was a little thinner than they would have liked, and to beware if you should be running on sharp rocks. Because the sole is, again, that of a barefoot minimalist shoe
— meaning it is thinner than your average running shoe—the FG might not absorb shock very well.
The shoe is very responsive, and this is largely due to its semi-curved shape—the shape allows it to adapt to your foot and shape itself around your foot’s movements. If you’re a self-professed barefoot runner, you probably want to feel the ground beneath your feet. There isn’t as much ground feel with this shoe as you might expect—it’s somewhat remote. But the sole is sufficiently thin, so the problem is likely the lugs on the outsole creating just a little bit of stand-off. You can also take out the 3mm insole
and this should help improve the ground feel. Most minimalist shoes have a good ground feel and first-rate responsiveness, and it appears that the Primus Trail FG is no exception.
Since the FG is a minimalist shoe, it does not provide much support, which may feel disconcerting to runners who are used to normal shoes or even stability shoes. But this is by design—Vivobarefoot believes less is more. The ankle collar helps support the ankle area, though, and the midsole provides support as well—especially to runners who have a neutral gait. The FG gives you just enough support to feel safe, and no more, but that’s really all you need.
The Firm Ground Outsole protects you on all types of terrain—slippery, wet, or steep (the FG is said to be great for hill sprints). You name it and you can conquer it with the Primus Trail FG. This outsole has a sticky rubber to help you grip the ground and to eliminate the possibility of slipping on any wet surfaces. The Quick Drain Zones help too by making sure that water will never pool in the shoe should you be running in wet conditions.
Previous reviewers have reported that the Primus Trail FG was excellent when running on steep terrain, slippery terrain, and various other types of trails—they ran distances equivalent to a half marathon and the shoe never slipped. When running on the pavement, you can feel that this shoe was truly meant for the trails.
of Vivobarefoot’s Primus Trail FG is more or less average for a barefoot trail running shoe—it’s not cheap, but it’s not overly expensive, either. By all accounts, the shoe is extremely well-made and high-quality, so you should be getting your money’s worth and more. The FG should last quite a while.
The Firm Ground Outsole of the Vivobarefoot Primus Trail FG has sticky rubber that gives you superb traction no matter what type of surface you’re running on. The chevron lugs on the outsole help with traction, too; the FG is a very grippy shoe. Previous reviewers have tested the shoe on all types of terrain, and because of the traction and grip strength, they have never slipped.
The Vivobarefoot Primus Trail FG is somewhat lacking in flexibility, and because of this, you may find that you struggle with your heel-to-toe transition when wearing the shoe. The fact that the sole unit has a very low-profile structure helps, however, and so does the no-sew construction. The semi-curved shape that adapts to your foot also adds flexibility. Compared to any running shoe, the FG is very flexible; it’s only when compared to other barefoot minimalist shoes that it falls just a little short.
Since the FG is a minimalist shoe, it won’t have much to offer in the way of stability—it relies on your natural foot movement. But a bit of extra padding around the ankle area in the form of an ankle collar helps add some stability, and so does the overall structure of the shoe.
Keeping in line with the Vivobarefoot brand, this is a zero drop shoe. Vivobarefoot
operates under the idea that a runner’s foot and natural movement is perfect just the way it is, so Vivobarefoot creates minimalist shoes that have a drop of exactly 0mm. They promise to put next to nothing into each shoe they create, believing that this is the best way to move and run—with minimal everything, including drop.
• Durable Firm Ground Outsole with chevron lugs and sticky rubber provides A+ traction
• The shoe is entirely vegan—no animal products used anywhere
• Quick Drain Zones and synthetic mesh upper give amazing breathability
• Seamless Fused Upper Material, wide toe box, and soft textile lining add extra comfort
• Aesthetically and stylistically pleasing
• Puncture-resistant sole ensures durability, as does the no-sew construction
• Very responsive because of the semi-curved shape—has a good ground feel
• Ankle collar gives you extra support and stability
The Vivobarefoot Primus Trail FG passes the traction and breathability categories with flying colors thanks to the Firm Ground Outsole and Quick Drain Zones. It is also wonderfully responsive, comfortable, reasonably priced, and has muted color options that are easy on the eyes. However, the FG is somewhat lacking in the durability and protection categories. The lacing system is not very durable, and the thin sole does not offer much protection on rocks and intense terrain. But the good features of this shoe definitely outweigh the bad. Overall, if you are looking for a barefoot minimalist trail running shoe, the Vivobarefoot Primus Trail FG would be an excellent choice.