Nike, famous for its beefy protective features and baroque designs in recent decades, has followed the market to return to its humble waffle iron beginnings from the 1960s and we love it. We reviewed their entry into the minimalist, racing flat market, the Flex Fury 2, and across the board in the racing flat categories it hit high marks. For racing flats, runners want light, natural, smooth, and uninhibited, all of which the Flex Fury 2 delivers. It does it while still giving enough room in its design to accommodate different running styles with both a low heel-to-toe discrepancy of just 4mm and also a well cushioned heel with 20mm of padding.
Nike Flex Fury 2 Review
Cons: Limited support, less durable, limited protection
Our Analysis and Test Results
The low profile, low weight Nike Flex Fury 2 was the best racing flat in our lineup, earning our Top Pick for Racing Flat award.
The Flex Fury 2 is an interesting shoe for responsiveness. At first glance, the shoe does not appear to be a particularly responsive shoe — it is lightweight, malleable, and has minimal reinforcement. But it has a few features that add it its responsiveness. In particular, its IU foam midsole gives it a bounce that other shoes need more structural support features to replicate. The major support feature that it does have, the flywire support cables over the saddle, also add to the overall responsiveness because they ensure that your foot is not dragging the rest of the shoe around when it moves. It helps the shoe fit more closely to the foot so that the there is no delay or lost energy in foot-to-shoe movement.
Even so, the responsiveness of this shoe is middling or just above average, which we expect from such a light, fast shoe. We placed this shoe on par with the Brooks PureFlow 6 and the HOKA ONE ONE Clifton 3, both of which have decent, but not superb responsiveness. Like the Flex Fury 2, the PureFlow 6 and Clifton 3 have spongy, malleable midsoles that spring and give back, but are not rigid like the Mizuno Wave Prophecy 5 (we scored the Prophecy 5 lower than expected because despite its desirable rigidity, it seems to eat more energy than it gives back). We suggest that you look into the Altra Torin 2.5, our highest scorer in this field, if you are interested in a highly responsive shoe.
The Flex Fury 2's midsole is made of soft, mushy IU foam that sits beneath Nike's pressure-mapped rubber pods aligned in a flat configuration across the broad outsole to absorb and disperse force on landing and give traction through to toe-off.
Overall, we feel this is a good thing for our body. Though it definitely helps the runner to land with their midfoot, heavy heel strikers can rest easy knowing Saucony's Kinvara 8 high abrasion EVA foam cushioning in the heel will absorb impact and reduce shock. Most runners will likely use this road shoe as a workout or racing shoe but many may also enjoy using it as a daily trainer once they are used to the more minimal style of heel-to-toe drop.
The outsole also features four areas of harder rubber placed in high impact areas to cut down on wear and give an added measure of durability and protection. It might simply be better to deal with a slightly heavier shoe and to use the harder rubber throughout the shoe so it doesn't wear as quickly.
The Flex Fury 2's upper features multiple layers of light mesh with a large mesh outer and fine, separated mesh interior that is both snug and malleable against the foot, creating a second-skin feeling that greatly contributes to our rating this upper one of the most comfortable in our cohort. Add to that a smooth, moderately padded heel collar and a thin, felt-like tongue, and you have a very comfortable shoe that will feel good through to the end of your run, which is a major reason we chose this shoe as our Top Pick for Racing Flat.
We must note, however, that just like the Brooks PureFlow 6, this shoe's thin, rigid tongue rubs against the skin when running, which causes irritation. This isn't as serious a problem in the Flex Fury 2 because the tongue is segmented into three flaps that fold a bit easier, but it is still irritating. We don't think this is a deal-breaker, but it is certainly something that needs to be reworked in future models.
We ranked the Flex Fury 2 near the top of the breathability scale. This model features two layers of mesh, but unlike other shoes with multiple layers, this shoe's inner layer is separated from the outer layer, allowing moisture to be wicked away from the sock or foot while allowing airflow to vent in through both the inner and outer layer. As with other highly comfortable shoes, this shoe's padded heel collar and super smooth tongue tend to keep in moisture and heat. We rated this shoe's breathability on the same level as the Saucony Kinvara 8 and Brooks PureFlow 6, but slightly below the Vibram V-Run, whose light build, thin upper material, and ventilation holes guarantee it to be a breathable shoe. We don't think there are any similar styles with superior breathability.
At 17.2 ounces for a pair of men's 11, the Flex Fury 2 is an extremely light shoe, outdone only by the Saucony Kinvara 8 and Vibram FiveFingers V-Run, with the Saucony Kinvara 8 being the more comparable of the two lighter shoes. With the Kinvara 8 being only 0.3 ounces lighter, weight will not be a deciding factor between the two shoes. The Flex Fury 2 has an ever so slighter, sleeker build and a slightly lower stack with a slightly higher heel-to-toe discrepancy (5mm instead of Saucony's 4mm), which may suit some runners better, particularly runners who tend to land less on their forefoot and more to their mid and heel.
One of the unfortunate downsides of such lightweight shoes is that their durability typically suffers and that is certainly the case with the Flex Fury 2, along with the other lightweight shoes in our review. The Nike Flex rubber pods on the outsole tend to wear away pretty quickly. There are other concerns about the flywire cables along the midfoot, which are vulnerable to tearing and coming loose, reducing the shoe's stability.
Most of the lightweight shoes in our lineup has the same average score in this field. Outsoles were especially short-lived, but thin uppers were also more likely to tear or lose their adhesive connections to soles. We found that the Brooks PureFlow 6 was slightly more durable here, which is one of the reasons we gave it our overall Editor's Choice. The PureFlow 6 will likely resist deterioration a bit longer than the Flex Fury and even the Clifton 3 whose tread and outsole deteriorated very quickly. However, the upper of the Clifton 3 was not super fine like the Flex Fury 2, so it may prove to be longer-lasting. While some models are very durable and sturdy, like the Mizuno Wave Prophecy 5 and the Brooks Ghost 9, they are very different, heavy styles. Therefore, if you are interested in a longer-lasting comparable, more durable model, we suggest the PureFlow 6.
At $90, the Flex Fury 2 is a very good buy for a speedy running flat. Keep in mind that this shoe is a performance shoe, so that $90 is a performance purchase, not a longevity purchase. You could find yourself ready for a second pair by the end of the season.
We absolutely love the Nike Flex Fury 2 as racing flats. The snug toebox with its smooth inner lining allow you to leave the laces loose if need be so that you don't feel like you're cutting off circulation to the top of your feet to keep from losing your shoe. We would have liked a lower heel-to-toe discrepancy for a racing flat, like the Altra's Zero-Drop Torin 2.5, but at 5mm, the Flex Fury 2 was one one nickel's width higher than the Brooks PureFlow 6, which was a phenomenal racing flat, but it won our overall Editors' Choice. At the end of the day, we are very happy with the Nike Flex Fury 2, but would like to see the heel pared down a bit while fortifying its stability features along the upper a bit more.
— Ryan Baham