Color: Hyper Cobalt/Black/Hyper Punch-Black-Hyper Jade
Nike's marketing pitch: A stability shoe designed to control pronation.
Surfaces tested on: Road, ambient temperatures of 19° C/66° F
Upper: Dual layer 'Flymesh', Flywire cord based lacing, inner sleeve.
Midsole: Triple density compression molded EVA, forefoot Zoom Air bag.
Outsole: Recycled rubber in heel, blown forefoot rubber.
Weight: 323 gms/ 11.4 Oz for a half pair of US11/UK10/EUR45, D Width. Unchanged vs. last year.
Widths available: D-standard (reviewed), Narrow (B), 2E(Wide) and 4E (Extra Wide) in select color choices. US only.
We’ve talked about this before, in another time and place.
Not very long ago, the running shoe world was a much simpler place to be in. You either bought a foamy chunk of a stability shoe, with an in-your-face medial post accentuated in contrasting grey and a hard ride to match. Or you picked up a ‘cushioning’ shoe, accompanied by a proprietary impact absorbing platform which the brand chose to spend its marketing dollars on. And we’re not talking about the Eighties or even Nineties; this is as recent as a decade ago, before the rise and fall of minimalist footwear.
Things have moved forward at breakneck speed, as if keeping up with the dog-year pace of evolution in the tech industry. Running shoes started getting categorized into broader classifications, confusing buyers and posing a wordplay challenge for brands. Blunt edged descriptions came into existence, with a set of words like guidance, support, stability and motion control being used to described a range of products which could earlier be slotted under a single category with nary a thought.
Functionally speaking, only a thin line separated these synonyms. And occasionally, most of these were used to describe one shoe, with marketing emphasis on a single characteristic. Example? The Nike Zoom Structure 17 (and 16) was one such model. Nike chose to use the word stability in the same breath as Structure 17, likely an attempt to anchor it with the familiar image of historical versions. But past two Structure models were anything but, their contrasting combination of soft and hard midsole foams inducing acute footstrike control – and ironically sacrificing stability.
That’s the deal with Nike, which has always evoked a love-hate relationship with their advancements, or shall we say, tectonic shift in product design. At times, you are blown away by the sheer brilliance of innovations like Flyknit. And during some years, Nike seems to take a few steps forward, and then an equal number of steps backwards towards correction. How else could you explain the shoe which is Zoom Structure 18, a brand new model far removed from its recent-as-last-year namesake?
We could be wrong, but it seems that the design of Structure 16 and 17 was encouraged by the stellar success of Nike Lunarglide. The latter was a new step in the sense that it promised to deliver pronation control, but within the boundaries of neutral cushioning. Given its universal acceptance and retail success that followed, the Structure 16 (same midsole as 17) obviously seemed like a stab to magnify Lunarglide’s midsole language. At the same time, Nike seemed to have missed the point that a similar shoe already existed in form of the slightly more expensive LunarEclipse. A product which at a slight premium, did a better job than the erstwhile Structure in every way possible.
That context set, we see the Structure 18 as a positive step to remedy that dilution in positioning. A step which takes the new Structure back to a time when the name conjured images of a firm and stable ride, and when there existed a functional connect with advertisement and on-ground performance. From a ride perspective, the new model is a throwback to some of the earlier models, and significantly distanced from last year’s version. While they were at it, the upper design also moves a few paces forward from an aesthetic standpoint.
What’s new in the Zoom Structure 18? The short answer is – everything. Much in the vein of this year’s refreshed Pegasus and the Elite, Nike’s evolutionary juggernaut has steamrolled ahead, causing drastic newness to sprout in every fiber of the shoe. We’ll be frank in saying that not all of that impressed us; there’s a mix of great and could-have-been-much-better areas. Good tidings should always come first, so let’s kick-off with the improvement, which in this case happens to be the new midsole.
Nike Structure dumps its dual density midsole set-up for the first time in three years, and moves to a triple density set-up. The idea of using three different foam densities together in a stability shoe isn’t a new one; current shoes like the Brooks Adrenaline GTS 14 and Beast 14 feature that. And even the Structure 15 and earlier versions depended on three foam pieces to deliver the stability promise. However, in Zoom Structure 18’s case, there’s a signature Nike spin on an existing concept.
The Structure retains the dual density arrangement of midsole foam pieces stacked together at a sharp angle, but tosses in a medial post of unfamiliar design. When viewed from the medial (inner) side, it looks like a wall, somewhat resembling a dam with its sluice gates. But like a bookend, this (pink) component extends under the outsole, its base turning inwards at 90 degrees.
To put it in other words, if this were a separate piece and if you happened to be staring down its length, the corner would appear to be vaguely L shaped. This is extremely hard EVA, and on this rests the second density (black color) of midsole foam. These two foams are joined together in an interlocked manner, the medial post exposing rectangular blocks of softer foam through its windows.
We’d like to point out that the density of lateral foam (white) is firmer than Structure 17, while hardness of the medially placed (black) foam is more or less unchanged. The Structure 18 midsole is compression molded, as compared to the injection molded midsole of Structure 17.
This process gives the foam a tightly packed feel, and a cleaner joining line between white and black colored foams. In Structure 17, colors bled over one another, making the bottom look a bit messy. The Structure 18 looks much better at the foam joint lines, with clear visual demarcation between densities.
Outsole design takes on the look and layout of Pegasus 31 and Zoom Elite, accomplishing coverage with a far lesser number of rubber pieces. Compare this – the Structure 17 had 14 individual bits of rubber stuck to the underside, and on the same area the Structure 18 uses a mere 6. This called for a radical re-arrangement of shapes, with larger and unbroken pieces being the new norm. Nike also chose to play around with materials, replacing the hard rubber clad Structure 17 forefoot with softer blown rubber.
The midfoot and heel section also sees a swap out of the BRS 1000 rubber, instead opting for recycled (Nike Regrind) rubber. This is the same rubber used on the Pegasus 31, and after using that shoe for four months, we can say that rear-foot outsole durability will be least of your issues. We’ll address forefoot durability in a bit.
The end result of all this? The Zoom Structure 18 is much stabler than before, and delivers a great balance between cushioning, motion control and overall stability. The 17 had a very pronounced lateral bias while rear-foot striking due to much softer lateral foam with deep compression grooves. This had the heel tipping dangerously outwards – something which ran contrary to its stability tag.
Though Structure 18 still maintains a lateral bias, it does so in moderation. The lateral foam is firmer than 17, a softness which lies somewhere between the new Pegasus 31 and Elite 7. As the medial layer of (black) foam feels unchanged in density vs. last year, the increased firmness of lateral foam brings greater consistency in compression during weight loading.
This brings a welcome aspect of stability to foot movement, and allows a far more gentle roll-in. The novel medial post set-up also differentiates the Structure’s ride from traditional dual or tri-density stability shoes. If you look at the design, you’ll observe that the pink coloured EVA only extends upto around 80% of the inside midsole wall. So when the foot loads over that area, the foam in contact is the softer (black) density. This prevents the super hard, dam shaped component from poking into your arch.
Overall cushioning loses the softness of Structure 17 and takes a turn towards increased firmness. Obvious reason is the mentioned change in midsole density and construction, but we are yet to consider the outsole design, which contributes to the firm ride. The Structure 17 felt way softer not only because of midsole materials, but also due to generous articulation of outsole rubber. Smaller pieces mounted on individual foam bases meant that they compressed and flexed better. The heel crash pad and forefoot area are good examples of that change.
Crash pad of the Structure 17 used to be this two piece design with a T-shaped flex groove. This made landings much softer, and likely contributed to increasing outward lean with each landing. Structure 18’s forefoot might have softer rubber, but is firmer and stiffer. The midsole foam in between is harder, and the outsole loses a flex groove too. This section has a large Zoom Air bag – you can see the faint outline in the image above.
This adds stiffness, but dials in a small amount of responsiveness which is more noticeable if you’re a forefoot striker. The Zoom Air bag, one less groove and firm midsole makes the Structure 18 forefoot much stiffer than the outgoing version. And if you wanted to know how a Zoom Air bag looks like in cross section, our Pegasus 31 review is a good place to go.
Not that this (harder midsole) is a shortcoming of the Structure 18; as a matter of fact, we see the renewed firmness as a desirable fitment, lining up with the shoe’s functional goal. If you’re upgrading from a 17, you will notice this change, and we wanted to let you the reasons behind it. Just laying out factual information as is solereview tradition, that’s all. A firm midsole also helps in faster runs – as mentioned, the Structure’s midsole density is between the Elite and Pegasus, which makes it suitable for fast paced training if you’re up for it.
Overall transition is better and smoother, as the sole design marries foam consistencies with revised rubber layout. There’s also the ‘Guide Rail’ section which starts laterally from heel to toe, identical to what’s on the Pegasus 31. These twin strips of rubber run parallel with a narrow groove separating them. As this runs near unbroken, save for a single groove across, it helps maximise full ground contact.
Grip isn’t better or worse off than Zoom Structure 17, either in wet or dry conditions, based on our experience of testing the shoe under both scenarios. But the change in forefoot rubber makes it more prone to wearing off than 17, with surface texture of lugs fading away after a few runs. That leaves the shoe with a durable midfoot and heel area, and average wear resistance in the front.
Under arch support sees an increase from a midsole perspective. The highest point of the curve is increased by around 2 mm, and at the same time midsole foam in contact with arch is thicker too. The pink colored wedge stops just short of the edge, and does not come in direct contact with the foot arch. Its hardness is insulated by the softer foam, which comes between the arch and interlocked insert. This heightens the sensation of arch support, while keeping the unwanted ‘pointy’ sensation at bay.
Insoles used are the same, regardless of the name change. Structure 17’s sockliner had ‘Fitsole 2’ printed on top, and that print is replaced with a huge ‘Running’ text running down the heel length, with subtexts of ‘stable ride’ and ‘Responsive’ just below. But these two insoles are identical except for the name. Like last year, the three layered insole has a hard casing on bottom, with a soft compound between it and the top cloth. The arch flare is softer than the rest, preventing any chafing in that area.
There’s a prominent contour on the footbed, but so was the case on last year’s. The Structure 18 appears to use a newer last (MR10) if the underside mold marking is anything to go, but we did not see any difference in the insole shape or construction.
All of the above was the good part. Which brings us to part two of the review, where we take a detailed look at the brand new upper and then let you know what we think of it.
The Structure 18 features a brand new upper design, and in the process debuts a new fabric too. We first got a good virtual look at this in August, when we chanced upon an inadvertently placed Vomero 10 video promo on the internet. After we posted screenshots of that, it disappeared from the source site. In that clip, Nike called the new fabric ‘Flymesh’, though they have refrained from using that term to describe the Structure 18 on their website. But for our convenience, we’ll call the upper fabric Flymesh.
It’s quite a looker, the Structure 18 upper. The Flymesh construction affords it the luxury of not having any overlays (except for the Swoosh logos). It is a single piece component covering the entire expanse of the upper, and joined only by a solitary heel seam. The design is an evolution of the mesh used in shoes such as the Lunarglide, where a single piece of mesh could be tightly knit in one area and perforated in another. Brands have started calling this an engineered mesh, a material mass commercialized by Nike in the footwear industry.
The difference this time is that instead of using a mono-color fabric, Flymesh features a dual coloured texture with a mix of blue and black in the reviewed colorway. It also contains two separate layers of fabric, but joined together by thousands of small knitted tacks, which appear as blue dots on the upper. The dots aren’t placed consistently, only used where the two layers need to be packed well together, whereas in other areas they aren’t there at all. Lower midfoot and heel for example, don’t have the meshes attached at all, and you can actually see them as two independent layers.
Material used is much coarser, bringing the Structure 18’s aesthetic overtones closer to Nike Flyknit Lunar 2, but minus the stretch properties. There are these ‘faux’ patterns on forefoot and heel area, which visually mimic overlays. These denser areas provide greater structural support in areas where it’s needed.
Eyelet panel is reinforced by a backing, and its edges have some kind of filmic lamination, which prevents fraying when laces rub against them. The lacing is quite narrow, with a small area remaining between opposing eyelets once fully laced up. These go over the tongue, the top of which is made of Flymesh and a soft mesh lining which is also used in the collar.
Nothing much to report from the heel area. Standard, internal stiffener which gives the area its shape, and collar lining has been changed to a plusher type. This is the same mesh used in the Vomero 9 and Pegasus 31, and an old material workhorse. When we reviewed the Vomero 3 around six years ago, Nike used the same collar lining, and has been seen in many models since. It feels soft to the touch, with a tried and tested record of no chafing. The Flymesh thins out around the heel curve , its perforated design showing through the contrast colored mesh underneath.
Structure 18 uses Flywire cords in an attempt to provide a secondary element of midfoot cinching. The design is asymmetrical, with five Flywire cords on arch side and three on the lateral face. This bears resemblance to the Structure 17 construction, where an internal strapping system wrapped the medial midfoot while outer side was plain jane lacing. The Flywire cords are guided by slits in upper midfoot, and they extend downwards sandwiched between two layers of Flymesh.
Like its 2013 avatar and some recent launches, Structure 18 comes equipped with a full internal sleeve. Our Lunarglide 6 teardown shows you the exact way in which this construction is achieved, with the sleeve starting slightly inward from the midsole edge for a snugger wrap. Except for the seams locking the tongue in, there are no other seams, making the interior smooth.
But for all the novelty, upper fit isn’t what it should be and borders on disappointing given the notable progress in the Structure 18 sole design. Sure, there are other positives to speak of. Like the shoe being much more greener, the new knit upper reducing production waste. Or the fact that it should end up being cheaper to produce, in a scenario where increasing costs aren’t doing the Portland based brand any favors. And the fact that the shoe looks absolutely gorgeous. But all of these factors have little to do with end user experience, which in other words, doesn’t necessarily translate into a great fitting upper.
To begin with, midfoot lockdown feels unsecured. We’ve have never been a fan of cord based Flywire, which pales in comparison to the original Vectran Fiber based version (2010 Lunaracer) or even the dynamic support strap when it comes to efficacy of foot wrap. We didn’t have great things to say about the Structure 17’s ride, but that shoe’s midfoot fit was great, owing to use of internal straps. The Structure 18’s cord based support fails to match that superior feeling of wrap.
For our reviews, we rate stability based on more than half a dozen different factors, and one of them is upper fit. This is the reason why some of our numeric ratings don’t seem to make conventional sense; for example, how could a ‘neutral’ shoe score higher on stability than a ‘support’ shoe? Depends on a case to case basis, but the reason behind the difference could very well be the quality of upper fit.
All the midsole and outsole features on a stability shoe count for nought if they aren’t married to an upper with optimum fit. The Structure 18 feels far less supportive inside than the 17 or some of other pronation control shoes in the market. Our observation particularly refers to the midfoot, where there’s greater foot play than what was experienced in Structure 17. This, in our opinion, slightly diminishes midsole’s effectiveness, especially when the shoe is designed to control pronation based on a rearfoot strike pattern.
The lacing pressure on Structure 18 feels extremely inconsistent, feeling tight at the top and then working its way down in decreasing intensity. The tongue is super thin for a shoe in this category. There’s hardly any padding inside, and the narrow lacing serves to only accentuate the issue. And if you go a little tight on the laces, the tongue tends to bunch up too. Not that the 17 had a great deal of tongue padding; the difference was wider lacing and use of spacer mesh, which came with its own in-built sponginess.
And in what is definitely an embarrassment for an inner sleeve, the upper portion of tongue sees some slide, shifting laterally during runs.
The frontend is a bit relaxed too, made possible by lack of overlays and change in lacing position which begins a bit distanced from the forefoot. While many people will appreciate a comfort forefoot fit, we would have preferred something snugger (sideways) to go with the tri-density midsole. Fortunately, getting multiple widths is an option in the United States, with the regular Structure 18 coming in four widths, ranging from narrow to extra wide. If you liked the snug feel of the Structure 17, then buying a B (narrow) width in S-18 might do it for you. Sizing is true with a thumb’s width separating the tip of the shoe and your toe.
That said, you’d be surprised to know that buying widths in the regular ($120) Structure 18 is a privilege afforded only to the US market. We spent some time on the internet visiting different Nike websites across the world, and discovered the lack of choices once you step out of mainland United States. Here’s a quick summary of the situation in a few countries. We chose these locations based on the web traffic we got last month – these four countries, together with United states are top five locations where we get readers from. Solereview also gets traffic from 185 more countries, and our guess is that they will fare equally or worse compared to the following examples.
(Note: These conclusions are drawn based purely on internet research, so if your experience is any different, please feel free to call it out in the comments section.)
United Kingdom – Widths not available in regular priced Structure 18. Citizens of her Majesty’s monarchy gets four widths only when they pay 35 extra Quids (+ three weeks of wait) for Nike ID.
Australia – Fact 1: Last year, 19 Million US runners participated in and finished a road race. Fact 2: That happens to be nearly the entire population of Australia Fact 3: Only one standard width in Structure 18 for all of them, no Nike ID. And the Structure 18 is priced at US $175. Ouch.
India – The country of incredible cuisine gets the extremely short end of everything when it comes to running shoes. No Nike e-store, ID or widths. Horrors of horrors, not even half sizes, it’s either 8 or 9 . No Saucony, Brooks, Mizuno, New Balance either. Add to that a 40-70% markup over US retail prices, with the Structure 18 selling at $160. And if you think their day was bad enough, they have to deal with things like this too.
Canada – The Nike Canada website does not have online shopping. Instead, it takes you to runningroom’s website, a third party retailer. No prizes for guessing, widths aren’t available, nor ID. And if you’re brave enough order them from US, expect to pay GST and customs. How much? Around CA$ 40 on Zoom Structure 18. Hard to see the silver lining here.
A few other things we didn’t like. You can’t wear the shoe barefoot. The upper lining is comfortable, no problems with that. The trouble is with the sockliner and its hard edges. Your bare skin feels the poke coming from the insole, killing the chances of going sock-free. The other area is complete absence of low light visibility elements on Structure 18, not even a tiny bit.
Considering that reflectivity is unavailable even on ID, it would appear that the only other option is to buy the Flash version, where you have to pay $15 extra and be stuck with a boring black color and a shoe too warm to run in summers. Much like tail-lights on a car, reflectivity isn’t a premium feature, it is a functional necessity. Most of other (brand) $120 shoes have it, and so should Nike. They should first focus on making runners happy, and Wall Street later.
The Structure 18 upper runs much warmer. It became very evident that the two layered Flymesh blocks the flow of air, and wearing this shoe is going to be bit of a bother when summer lights up the streets. The contrast in breathability between Structure 17 and 18 was remarkable; the forefoot of Structure 17 felt amazingly ventilated when switching from a pair of 18’s.
But we see the funnel like fit as the Structure 18’s true weakness, as we strongly believe a supportive upper has to complement a stable platform – which the Structure 18 has. The fit can be remedied to some extent by choosing another width, but then, that option is limited only to the United States.
To bring things to a close, the new Structure 18 has a vastly improved ride which delivers on what it promises to do. Yet, the less than ideal upper fit of the upper makes you feel that it could have been much better. This is much more noticeable if you’re transitioning from the Structure 17 – as a standalone shoe, it is likely that you will not see the Structure’s fit in a bad light.
And how does something like a Lunarglide 6 compare to Structure 18, two very different shoes they may be? Since Nike also positions LG6 as a support shoe, some clarification is in order. The Lunarglide 6’s cushioning is softer because of a Lunarlon foam core inside its midsole. The upper is snugger vs. the Structure due to lacing extending into the forefoot, and narrow heel counter molding. Overall the shoe weighs 10% lighter, but the trade-off is outsole durability, which is superior on the Structure 18.
The release of Zoom Structure 18 also completes Nike’s Zoom pack this year – the other models being the Pegasus 31, Elite 7, and the Zoom Streak 5. The year 2015 will kick off with the Vomero 10, which appears to use an upper identical to Structure 18, with an all new sole unit.
(Disclaimer: Solereview paid full US retail price for the shoe reviewed)
Note: We have discontinued the practice of numerically scoring individual footwear attributes. Instead, we use the same rating methodology and arrive at a single numeric score. Some of the elements from the numerical rating have been included in the sensory scoring format.
And here’s the scoring range: Great (dark green) – 90%- 100%, Good (light green) – 75%- 89%, Average (amber) – 60%- 74%, Poor (red) – lower than 59%