Understanding the meaning and design principles behind the tech names will help you navigate through the catalog faster. Here’s an overview. Flyknit is a special woven fabric that makes the upper of a shoe feel like a sock, by placing yarns and knits strategically around the structure in order to support the foot of the runner when needed and leave it free everywhere else. Flyknit running shoes are lightweight: a light yarn replaces multiple stitched or glued panels. Flyknit also allows for extremely precise upper fit, being able to seamlessly integrate tight-knit areas where support is needed and wide-knit areas to allow for flexibility. Flyknit is environmentally friendly as it produces 60% less waste than traditionally constructed running shoe uppers. This technology is Nike’s latest, so expect to pay a premium for Flyknit shoes. Most notable examples of Flyknit shoes are the Flyknit Racer (as the name implies, a fast and light shoe for racing distances all the way to the marathon) and the Nike Free Flyknit (an extremely flexible and lightweight running shoe to strengthen and train the muscles in your feet). FlyKnit Loft is used on the Infinity Run. AtomKnit is a new, more advanced type of FlyKnit material. The difference between AtomKnit and FlyKnit is that AtomKnit is steamed and stretched. AtomKnit is extremely lightweight, very breathable and does not absorb water. AtomKnit is only used on the flagship shoe, the AlphaFly Next%. VaporWeave is an engineered, woven mesh with a smooth, plastic-like feel which is light and strong. Its main advantage is that it doesn’t absorb water so during a race, the shoe will not absorb sweat and weigh you down. VaporWeave is very breathable but doesn’t conform to the foot so creasing may occur. VaporWeave is used on the VaporFly Next% and the Zoom Fly 3.An explanation of Nike running shoes technologies
Upper technologies
Flyknit
FlyKnit Loft
FlyKnit Loft is a FlyKnit variation which is breathable and durable. It has 3 distinct layers which help keep the foot secure. It has a smooth, plastic-like feel and does not stretch.AtomKnit
VaporWeave
Engineered Mesh or Flymesh
Engineered Mesh features more prominent perforations than traditional mesh. It is a completely different construction than the previously mentioned Flyknit and shoes with Engineered Mesh usually have a lower price-point.
Engineered mesh is used on the Pegasus 37, Miler, Vomero 14, Downshifter 10 and Winflo 6.
An overview of Nike running shoe sole and cushioning technologies
Midsoles of running shoes are made of foam. Each company has their own trademark foam mix that tries to achieve the following: be as lightweight as possible, be soft in order to absorb the impact with the ground, be elastic (in order to compress on impact and release propelling you forward), be durable (foam does deteriorate with use, so all foam materials need to be engineered to maintain its characteristics for a decent amount of time).
React Foam
React is a styrene-based material which is a synthetic rubber. It is lightweight, durable and resistant to temperature changes. React doesn’t have sink-in softness but has a dense, rubbery feel with a noticeable spring.
React Foam is used in the Pegasus Turbo 2, Odyssey 2, Vomero 14, Zoom Fly 3, Infinity Run, Terra Kiger 6, Miler and Pegasus 37.
Nike ZoomX Foam
ZoomX delivers Nike Running’s greatest energy return. It is featherlight, cushioned, springy and great at preventing foot fatigue. ZoomX is quick to compress and snaps back instantly.
ZoomX is used in the VaporFly Next% and AlphaFly Next%.
Fly Plate
FlyPlate is a light carbon-fibre plate which delivers a snappy sensation with every stride. It provides a propulsive feeling to increase your pace.
FlyPlates are used in the AlphaFly Next%, the VaporFly Next% and the Zoom Fly 3.
Cushlon
Cushlon is a mix of Phylon and rubber additives that makes it lightweight and responsive.
Nike Air
Everybody knows Nike Air. That’s how Nike got big in the 80s in the first place. But do you exactly know what Nike Air is ?
Nike running shoes in the “Air” category often use Cushlon foam in their soles. Soft and resilient, this foam has 2 limitations: it is quite heavy (as most foam is) and it is not as “bouncy” as many runners expect their shoes to be.
The solution? Cutting off areas of the Cushlon-foam-made midsole and filling them up with plastic bags filled with “Air” (Nike’s secret gas compound). What this achieves is to reduce weight (by replacing the heavy foam with a very lightweight “airbag”) and to increase cushioning (being these airbags softer and springier than the Cushlon foam).
Depending on the shoe, you can have Nike Air bags in the heel, the toe, or both.
Air bags come in 3 formats: Air, Air Max and Zoom Air.
- Nike Air -> the most common, medium sized air bags that fit well especially under the heel.
- Air Max -> very thick and highly cushioned bags of air. In our opinion too unstable for proper running, mostly used on lifestyle shoes.
- Zoom Air -> the thinnest units, ideal to fit in low-profile shoes. They were initially developed for soccer shoes, where normal Air bags would not fit inside the ultra-thin sole
Nike Free
Nike Free is a concept. Started around 2005, the idea was to create a shoe that is so flexible that leaves the foot completely free to move in the most natural way.
Some people object that the Frees are still very cushioned shoes, therefore preventing the runner to have a true feeling for the ground below them.
While this might be true, the extreme flexibility of the Free sole unit, combined with very open-mesh and unconstrained upper make for a treat.
What do the numbers next to a Free shoe mean?
Nike abandoned the use of numbers in the Nike Free line in 2016, when they completely revamped the category.
Originally Nike Frees came in different versions, depending on how flexible they were. Their flexibility was ranked on a scale that goes from 1.0 to 10.0, where 1.0 means “bare feet” and 10.0 is a traditional running shoe.
In 2016, with the coming of the new auxetic construction, the Nike Free range is completely new and the numbers are gone. We’ll go through the line and the models in a minute. Keep reading!
Nike Free Auxetic Construction
The new principle behind the Nike FREE line of running shoes is called “auxetic design”.
When your foot hits the ground, it expands both in length and width. Picture bouncing a ball on the floor: it squeezes and deforms because of the impact, then the opposite happens while it bounces back.
Nike engineers were looking for a way to design a midsole so that it would expand in both directions during the foot strike. The issue is that most materials, when stretched in one direction, become smaller in the perpendicular direction. Again think of an elastic band. If you pull it to stretch it long, it will most likely become narrower in the middle.
The auxetic design, characterized by the triangular cuts you see in the picture, allows the sole to do that. A stretch in one direction will equate to a stretch in the other.
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