Vivobarefoot Primus Lite III vs. Primus Lite Knit – Does the upper make all the difference?

I’m a big fan of the original Primus Lite III, but my only complaint was the stiff recycled upper used to provide a solid lockdown. The Primus Lite Knit seems to be a logical solution, but can it perform as well as the standard Primus Lite and still provide a great fit? 

In this post, I’ll take you through the key features of the Primus Lite and the Primus Lite Knit. Highlight the differences and help you decide which model is best for your needs. 

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One of the biggest differences between the two models is the fit. 

The standard Primus lite is shallow and narrow in the midfoot. Meanwhile, the Knit version is more forgiving in width and depth. 

Even though both shoes are the same shape, the upper material makes all the difference. Sometimes, I found the midfoot too snug in the Primus Lite. I would loosen the laces to get around this, and all would be fine. But for the knit, I found the opposite. The upper seemed “baggy” to me. I had to tighten the laces so much that I had some bunching of material. 

Do the shoes run true to size?

For the Primus Knit, I’d suggest selecting ½ a size smaller to find the perfect fit. ½ a size isn’t huge; it amounts to around 3.5mm, but it can make a difference with a knit upper. Because of the knit design, you want the upper to be snug because the lacing cannot provide a solid lockdown as it usually does with stiffer uppers. 

The Primus Lite II runs true to size. As long as you buy a pair with enough length, you’ll have no issues with forefoot width (which I have seen others have problems with). They may feel long at the start, but trust me, you’ll want the space to embrace the room and allow your toes to wiggle! 

If you have a high-volume foot, opt for the Knit upper. This will allow the material to expand to the size of your foot. The standard Primus Lite does little to accommodate a deep foot due to the stiffer upper materials. I have a reasonably average foot, and it works for me, but try the Knit version if you require more room in your shoe. 

Are the toe boxes wide?

I love the squared-off toe box around the big toe. If you have a natural toe splay, your big toe will point forward or even towards your center line. Conventional toe boxes often taper in at the big toe, constricting an optimal big toe motion. Looking down at Vivobarefoot shoes, it’s evident that this is not the case. The toe box is nicely squared off at the big toe. 

Vivobarefoot shoes taper aggressively on the little toe. This is where your foot shape comes into it. If you don’t have a large toe splay on the little toe, or it’s turned in like me, the toe box will work fine. But if you have a wide fan-like shape to your toes, you may want to look to another brand like Lems or Softstars. 

Generally, these are both minimal shoes using the same 4mm outsole. But the upper does create a different barefoot feeling. 

The Primus Knit generally provides a true unobstructed barefoot feel but at the cost of lateral stability. This leads to the Primus Lite III being a better all-around and gym shoe. 

Are the shoes flexible?

The Primus Lite models do the job if you’re looking for a ground feel with some protection. There’s only 4mm of rubber under your foot! Add the insole (optional) to that, and it’s around 6-7mm in stack height. Keeping the shoe flexible in every direction you can think of. 

The knit upper allows the shoe to flex more than the standard Primus Lite. I noticed a crease point forming at the forefoot when reviewing the standard Primus shoe, which was caused by the stiffer upper materials. However, the Knit material used in this version offers greater flexibility throughout the shoe. For me, this creates a more “natural” barefoot feel.

Does the lockdown provide security?

While the knit upper is comfortable, your foot can slip inside the shoe. Laces are one thing, but if the material you’re pulling around your foot is stretchy, you’ll never achieve a secure fit. This was most notable when picking up speed and taking corners quickly. 

For any gym work or court sports, the Primus Lite III works much better. This model has much more lateral stability, meaning your foot doesn’t slide over the top of the shoe. The same cannot be said for the Primus Knit. 

Is there too much ground feel on rough terrain?

If you’re likely to hit the trails, use another shoe. While you can run on some soft dirt trails, gravel may be rough on the feet. Look to the Primus Trail range if you’re doing any trail running. 

Most of you will be fine on city streets. If you’re used to barefoot shoes, you’ll enjoy the minimal feeling of the Primus Lite Knit. But if you’re new to this, slowly build up to barefoot. Just take these out on a 15-minute walk and build from there.

Can I run without the insoles?

Both models have a fully removable insole that drops you an extra 2-3mm closer to the ground. I would love this, but it’s only an option for those with deep feet that fill out the shoe. Rather than being a decision about feel, having the insole in or out is more a decision of fit. Most will find the Knit fits better with the insole, but that seems to be the opposite with the standard Primus Lite.

How long will the outsole last?

I have over 500km on my standard Primus Lite shoes, and while they are showing wear, I could get another 500km. The durability looks promising because of this experience with the older outsoles, and these are the same outsoles seen on the Knit and standard.

Can I repair the shoe?

Sadly, Vivobarefoot does not offer repairs on the Primus line. But many of their other casual models can be returned for repairs and sprucing up. However, they do have a recycling program once you’ve finished with the shoes. 

Once you can’t repair or don’t need them anymore, send us your old Vivos and we’ll make they sure they’re given a second life, or if they’re really well-loved, we’ll store them until we launch our recycling solution.

Are Knit uppers durable?

In a word, yes. But a shoe made for the urban street will unlikely meet thorny bushes. Because the upper martial is 100% knit, there’s a chance it could rip. Just be mindful when hiking in the woods or bushwacking through the back garden. Throw some wellies on instead.

If you need more durability, opt for the Primus Lite III. The more rigid recycled plastic will withstand a lot of beating before breaking down. That’s not something I could say about the Knit version. 

Glue problems with the outsole connection

In the past, I’ve seen the outsole become unstuck, particularly around the forefoot bend. The Primus Lite Knit will have an advantage here because less pressure will go through this area because of the knit material, meaning it’s less likely to come unstuck. 

If you choose any shoe from the Primus line, you’ll end up with a good shoe. 

The main difference comes down to fit and feel. 

If you want a deeper shoe, which is more forgiving in width: 

• Go with the Vivobarefoot Primus Lite Knit

If you need a durable shoe that performs while running, at the gym, and everyday life

• Go with the Vivobarefoot Primus Lite III

If you’re looking to get as close to barefoot as possible

• Go with the Vivobarefoot Primus Lite Knit

If you’re looking to go the distance with a minimal shoe 

• Go with the Vivobarefoot Primus Lite III