Vivobarefoot Primus Trail Flow Mid hiking boots review: an ultra-minimalist fastpacking boot for barefoot veterans

First impressions

If you read my review of Vivobarefoot's Tracker Forest ESC hiking boots you'll know that I'm a fairly recent convert to the brand, having never worn barefoot shoes or boots until a year ago.

I'd always thought of barefoot afficionados as being in something of a cult, but, as you'll also know if you read that review, I'm now a full convert. Yep, I drank the Kool Aid.

So I jumped at the chance to test the brand's new fast hiker, the Primus Trail Flow Mid - a taller iteration of its classic Primus Trail Flow hiking shoe and pretty much the opposite of the Tracker Forest ESC. Here's how it performed:

Fit

Since I was lured into the barefoot movement I have slowly converted all my active shoes to barefoot versions, but I lacked a boot for summer hikes, so I was excited by the prospect of the much lighter Primus Trail Flow Mid filling the gap.

I usually take an EU 42 / UK 8.5 in Vivobarefoot styles, and these fitted as I expected, with a thumb’s width of space at the end of the toes to allow room for movement and grip. However, I struggled to get a precise fit around the heel and ankle with the fast lacing system. My go-to hiking socks are some pretty plush Bridgedales and I also have wide feet, but I still had to cinch the boots tight enough to leave a long length of spare cord beyond the toggle fastener.

The laces come with a small clip to allow you to attach any spare cord to the lacing at the front of the foot, and stop it flapping around, but my spare cord was longer than the last lacing point, so instead I tucked it under the front lacing.

I do appreciate these kinds of lacing systems are a weight-saver and make it quicker to slip in and out of your boots, but it does mean I can only really wear these hikers with thick socks, while my Tracker Forest ESCs can be pulled tighter and therefore worn with thinner socks in warmer weather.

All that said, with the right socks, these boots were very comfortable to wear, even if the heel didn't feel as locked in as I'd have ideally have liked.

On the trails

If you're new to barefoot shoes then here's a quick primer: they have zero drop, which means there's no height difference between the heel and the ball of the foot and toe.

So that's the first thing you'll need to get used to. But, along with a generous toe box and lots of flex - both design features to let your feet actually move as intended – barefoot shoes also usually have far less cushioning than standard shoes.

This combination of factors is why it takes a while to get used to wearing them (Vivobarefoot recommend about six weeks of daily wear), and it's also why I wouldn't suggest the Primus Trail Flow Mid as a first pair of barefoot hoofs.

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These specific boots have a 1.8mm sole base and no insole, which means you can feel everything on the trail. It doesn't mean your feet aren't protected, far from it, and I'll talk more about that in a bit. But if you're used to fairly stiff boots then suddenly being able to feel each tiny pebble you tread on may just be too much.

Happily, a year into being a barefoot bore, this level of sensation doesn't faze me at all. In fact, I welcome it. I have a lengthy history of knee problems that started in my 20s, and consequently my left knee doesn't flex past about 90 degrees. This can make me a little clumsy and also make descents in stiff boots challenging. I avoided barefoot shoes for years because I was worried that the lack of cushioning would be too tough on my poor knee. But the flex and trail feel provided by barefoot designs - and these ones are particularly thin and supple - actually keep me far steadier on my feet.

I tried them on some pebbly descents in the Lake District and found I was even more confident wearing them than in the Tracker Forest ESCs, probably due to the greater trail feel and flexibility. I actually felt nimble at times, which isn't something I ever hope for due to my various injuries.

Waterproofing and protection

Vivobarefoot describes the Primus Trail Flow Mid as water repellent, but to me that feels like a stretch. Yes, the woven fabric on the lower foot is impressively water resistant, and I walked through multiple shallow streams in them without an issue.

However, as soon as I tackled something deeper, water quickly seeped in through the knit collar, which starts fairly low down and didn't feel water resistant at all. This left me with sodden socks, and no way for the water to drain out. I haven't particularly minded this over the summer and early autumn, but it's why I will be sticking to dry days to wear these boots whenever possible.

They do dry out quickly, but the lack of insulation underfoot and on the upper means they're more suited to three-season hiking. I can see them being very popular with California-based hikers, who are blessed with balmy weather and fast, dry trails year round, and who are probably the only consumers who can buy the cream Peyote version without it being ruined in five minutes flat.

So, this isn't a boot for the worst conditions, but it's still reasonably protective, with a welcome toe bumper right where you need it, and a rubber rand that wraps around the foot. The woven part of the upper has multiple tough layers of fabric that should see off anything pointy or sharp, but the knit collar means there is still some vulnerability around the upper ankle.

Weight

If all this sounds like one gripe too many, then I want to clarify that I actually love these boots. They're not perfect, but for someone who struggles not to trip even walking down stairs sometimes, they left me feeling light on my feet and more capable of technical trails and scrambling than I'm used to.

I also adore how featherweight they are. I passed one to my partner, a seasoned hiker, and he looked incredulous, saying "There's nothing there!" They really are barely there in all the best ways, with my pair (a US women's size 10.5) tipping the scales at just 8.7oz (246g) per boot.

Grip

The Primus Trail Flow Mid also have a decent amount of grip. It's clear they're designed for drier conditions than we are usually greeted with in the UK, but the 3.8mm multi-directional lugs did a good job of keeping me upright, and the braking lugs at the back of the outsole caught me when I did occasionally slip on wet rocks while traversing streams.

Environmental impact

Vivobarefoot is among the many outdoor brands that have read the room, and taken a hard look at their manufacturing processes to make them more sustainable. These boots are advertised as vegan, with the proviso that it's not been possible to establish that the smaller components used in their creation (including glues and dyes) meet vegan best practices. The fact that the brand states this clearly rather than greenwashing is welcome, as is its scheme that allows you to recycle any old worn out pair and get a voucher for 20% off the cost of a new pair.

Due to their limited waterproofing and insulation, the Primus Trail Flow Mid aren't going to become my go-to winter boot. Honestly, I'm gagging to get my Tracker Forest ESCs back on now that the colder months are on their way.

However, for milder days, and for anyone who lives in a drier climate, they're a great option. If you've not worn barefoot shoes or boots before I would strongly recommend trying a pair with thicker soles first. But if you're already in the cult, you won't be disappointed.

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