New Balance is adding to its barefoot-inspired Minimus collection with the introduction of the innovative HI-REZ road shoe. This shoe is designed for the minimal runner looking for the latest cutting edge product to enhance a hyper-real sensory running experience. The new Minimus HI-REZ construction delivers a completely different experience for the runner by allowing the foot to move as it would naturally while still offering underfoot protection.
This new addition to the Minimus collection is made with 42 independent lightweight midsole pods mechanically bonded to a durable yet flexible fabric base that allows the shoe to move and flex in closer unison with the foot. The midsole pods are a high abrasion ground contact EVA which offers a strong balance between durability and shock protection with additional outsole rubber post-applied in areas that needed extra resilience and traction.
Made with the NB Minimus Zero drop last that eliminates any height difference between the heel and toe, both at around 6mm, the shoe encourages a midfoot strike while an enhanced width allows for a natural forefoot splay.
The upper is made of a skeletally engineered FantomFit material with a support structure in the form of an hexagonal print pattern fused to a single layer of breathable mesh, giving the foot crucial lightweight support.
In keeping with all shoes in the Minimus collection, HI-REZ encourages the runner to go sockless with interiors created to fit the bare foot comfortably.
The tongue connects seamlessly to the lateral side of the shoe to further encourage barefoot use and reduce potential points of irritation. The sole and uppers come together through a unique stitching process and are reinforced with a rubber that runs along the entire perimeter of the shoe.
According to New Balance Lead Designer Chris Wawrousek, building the upper was a constant battle of opposing design decisions: materials versus protection; stretch versus structure; breathability versus support. The New Balance design team had to be strategic in balancing minimalism with practicality. As a base material, the designers chose a flexible, light synthetic performance mesh, which allowed them to eliminate irritation points inside and keep support elements on the outside.
In deciding where to put the seams, the designers identified certain areas that would allow them to shape the shoe correctly and also minimize the number of seams needed throughout. A close inspection of the Hi-REZ upper reveals a thin rubber layer used to reinforce the side seams, as well as a rubber tape overlay throughout that preserves the integrity of the mesh.
Constructing the upper in this way let the designers target specific zones around the shoe to have a certain amount of stretch in one area and a very specific amount of support in another.
From the early development to final product testing, the goal of New Balance Sport Research Lab was to determine how much more sensation people could feel underfoot in the Hi-REZ versus other minimal running shoes, a measure that’s not easily quantifiable. Because of the shoe’s extreme flexibility and minimal design, traditional testing methodologies cannot be used. According to Sports Research Engineer Pedro Rodrigues, they developed two unique tests specific to the Hi-REZ: Filament Test and Perception Test.
For the Filament Test, they use a thin, stiff filament, and applied different amounts of force to specific areas underfoot to determine sensitivity at certain thresholds. For the Perception Test, they asked several people to wear the shoes on rocks and rate the amount of texture they could feel. The results from both clearly showed people felt significantly more sensation in the Minimus Hi-REZ than either the NB Minimus Zero or the NB 1080v2.
So how did the Minimus HI-REZ perform?
My US Men’s Size 10.5 of the Minimus HI-REZ weighs in at a scant 4.2 ounces. The shoes slip on easily and sockless as usual, it felt super-comfortable. I’m surprised the standard width HI-REZ fit my 2E+ width feet – the uppers and outsole are so soft that it contours to my feet. However, New Balance is launching with only the standard width…
At first glance, I was worried that I will feel the gaps between the midsole pods on my barefoot – I had used my fingers to feel them on the footbed before I put the shoes on. But it felt normal and comfortable instead! The HI-REZ felt like a sock or thin glove on your feet – even better than the Minimus Zero Trail. The HI-REZ uppers are much more comfortable and the taco-like tongue wrap is my preferred configuration. And super-breathable to boot.
But there is a downside to the breathability – I ran in really cold weather one morning and my toes froze. My toes were so numb that the footbed felt like a piece of plywood.
There is absolutely nothing in the HI-REZ from holding or preventing your foot from its natural movement. The HI-REZ is so flexible in all directions. The outsole rubber posts are applied to the exact spots where my foot exerts the most pressure/wear (midfoot/forefoot strike) thus making it more durable and having good traction.
I’ve tried speed work on a tartan rubber track in the HI-REZ and there are many times where I felt the need to slow down (on the curves) and not slip. Other than those situations, traction is very good on rubber, asphalt, non-technical trails, and concrete.
One question that came to mind is, “Is the bottom waterproof?” I believe it is water resistant. I soaked the Minimus HI-REZ in water and it floated nicely. But after 2 minutes, water started coming in. In general, it is water resistant enough that if you are not standing still on a puddle, you’re good to go. The water will also come in through the uppers easily as expected.
You can also see how thin the footbed is. Note that between your bare foot and the ground is less than 6mm. The pods are about 5.5mm so that leaves about a 0.5mm fabric footbed!
For those looking for the most minimal running shoes in the market, the New Balance Minimus HI-REZ fits the bill. The only other comparable shoe is the new Merrell Vapor Glove. And both are awesome shoes.
I would have rated this a 5.0 star shoe if these two minor items were not present:
- I question the durability of the pods – both mileage wise and whether they will come off the footbed. I have less than 50 miles on the shoe for this test but time will tell.
- The Minimus HI-REZ cost a whopping $120 – it is not cheap! The Merrell Vapor Glove is only $80. But there is a lot of advanced technology and design innovation from New Balance there.
But overall, the Minimus HI-REZ is an incredible shoe: awesome design, zero drop, super-lightweight, great proprioception, super-flexible, and ultra-comfortable racer. And it will definitely get you noticed with its bright and vibrant colors.
*Product provided by New Balance. CMP.LY/1 Review
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