Our verdict

When it comes to lightweight daily trainers on a budget, Nike nailed it with the Free RN NN. "Barely there", is the most apt way we can describe this shoe that truly feels like we're running barefoot. With its snug, sock-like fit the shoe seems to wrap itself around our foot while its incredibly flexible and forgiving nature leaves us feeling fresh after every session. Although we were certainly able to hit high speeds in this feathery shoe, we found that it's best suited for more steady paces for short to moderate distances.

Pros

  • Feather-light on the foot
  • Extremely flexible and comfortable
  • Good impact dampening
  • Very accommodating toebox
  • Secure sock-like fit
  • Works well in the winter
  • Keeps the feet warm
  • High-quality and durable upper
  • Can handle gym day and some other activities
  • Sleek design
  • Budget-friendly

Cons

  • Too toasty for warm weather
  • Not ideal for speedwork or long distances
  • Too broad for those with narrow feet

Audience verdict

75
Bad!

Who should buy

We recommend the Nike Free RN NN as an excellent choice for: 

  • Runners with a neutral stride who prefer lightweight and agile daily trainers with a bare-there ride
  • forefoot/midfoot striking runners who want a flexible mid-drop road shoe that can bend it like Beckham
  • Those in cooler climates looking for a warm shoe that performs well in frigid conditions
  • Active individuals in the market for a shoe that can take on other fitness activities and gym days

Nike Free RN NN main

Who should NOT buy

The shoe's Flyknit upper demonstrates lackluster breathability in our smoke test which makes it a less than ideal choice for warm weather runs. The Allbirds Tree Dasher 2.0 is a more breezy option that also has a sock-like fit.

While the feathery nature of the Free RN NN does allow us to push the pace to a certain extent, it lacks the responsiveness to be a dedicated tempo shoe. We recommend checking out the Saucony Kinvara 14 as a better speedy alternative. 

Additionally, long-distance runners will benefit from a shoe with more protective cushioning underfoot like the Puma Magnify Nitro 2 instead. 

Nike Free RN NN cut

Runners with narrow feet will find themselves floating around in the Free RN NN's spacious toebox. We recommend checking out the Skechers Go RUN Ride 11 for a more snug fit. 

The Free RN NN is a neutral shoe with a ride that's not at all supportive for those with overpronating strides. The Nike Structure 25 is a stability shoe that promotes a more neutral gait that will suit those runners better as daily trainers. 

Breathability

We pumped the Free RN NN full of smoke to get an idea of how breathable it is. As we can see from the footage of the test, it takes quite some time before smoke is finally able to start filtering out the shoe. It struggles its way through the Flyknit upper in wisps that seem to escape haphazardly throughout the shoe. 

The Saucony Triumph 20, meanwhile, is a true smoke show in this test earning it a perfect 5 out of 5. 

This lackluster performance earns the Free RN NN a breathability score of 2 out of 5 which confirms its warm and insulated nature. While this may not be ideal for hot days, it's certainly beneficial as the mercury drops during the cooler months. 

While the light is visible through a cross-section of its upper, the Free RN NN doesn't allow any of it to peek through any pores in the material. This serves to illuminate the shoe's below-average breathability to a certain extent. 

Our microscope provides further clarification as it shows how dense woven the shoe's Flyknit upper really is; with only barely perceptible little gaps that allow any kind of airflow through the Free RN NN. 

Nike Free RN NN Breathability

Nike Free RN NN Breathability 4
Test results
Free RN NN 2
Average 3.8
Compared to 230 running shoes
Number of shoes
1
Breathability
5

Durability

Toebox durability

For what it lacks in breathability the Free RN NN Flyknit upper makes up for in strength. Firing up our Dremel to 5K RPM to simulate some extreme wear and tear, we set it against the shoe's toebox with 3.2N of force. 

Upon inspecting the damage in the aftermath of the test, we found that our tool had merely frayed some of the outer material and failed to penetrate the toebox all the way. This earns the Free RN NN a toebox durability score of 4 out of 5 which is very respectable for a daily trainer with no protective overlays. 

Nike Free RN NN Toebox durability

Compare that to the devastation we had wrought upon the ASICS Gel Pulse 13 in this same test.

Test results
Free RN NN 4
Average 2.4
Compared to 164 running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

Next, we set our sights on the heel collar and set our Dremel against the Free RN NN once more. 

It proved to be even more resistant to the abrasive force of our tool's grinding element as after four seconds it was barely left with a scuff. This leads us to give the Free RN NN a well-earned perfect score for heel padding durability. We therefore don't believe that wearing a hole in the heel from excessive rubbing will be the cause of retiring this shoe early.

Nike Free RN NN Heel padding durability
Test results
Free RN NN 5
Average 3.2
Compared to 160 running shoes
Number of shoes
1
Heel padding durability
5

Outsole hardness

Pressing our durometer against the Free RN NN's outsole gives us a reading of 79 HC. This is about as hard as our current lab average which usually indicate a good mix of grip and durability. 

Nike Free RN NN Outsole hardness
Test results
Free RN NN 79.0 HC
Average 80.5 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 281 running shoes
Number of shoes
52.1 HC
Outsole hardness
93.0 HC

Outsole durability

To test that last claim, we got the Dremel spinning at 10 K RPM and set it against the Free RN NN one last time. 

After twenty-two seconds of punishment, we found that we had lopped off 0.8 mm of rubber from the outsole. This makes the Free RN NN's outsole about as durable as average and leads us to predict that the shoe should last a good 400 to 500 miles before the tread starts giving out significantly. 

Nike Free RN NN Outsole durability
Test results
Free RN NN 0.8 mm
Average 0.9 mm
Compared to 142 running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

At 2.5 mm thick according to our caliper measurements, the Free RN NN's outsole is a little shy of our current lab average. This is a good amount of rubber to wear through without weighing the shoe down, especially considering the rubber's performance in our last test. However, with the shoe so lightweight already, a touch more rubber would definitely add to the shoe's longevity. 

Nike Free RN NN Outsole thickness
Test results
Free RN NN 2.5 mm
Average 3.2 mm
Compared to 300 running shoes
Number of shoes
0.0 mm
Outsole thickness
6.6 mm

Weight

As alluded to in the previous section, the Free RN NN is incredibly lightweight. Tipping our scale at only 6.9 oz (197g), it's truly a barely-there running shoe. When combined with its snug, sock-like fit, we had to keep checking our feet during our test runs to make sure they were still on. 

Nike Free RN NN Weight
Test results
Free RN NN 6.95 oz (197g)
Average 9.35 oz (265g)
Compared to 301 running shoes
Number of shoes
5.26 oz (149g)
Weight
12.56 oz (356g)

Cushioning

Heel stack

The Free RN NN has quite a low profile, with its stack measuring only 25.6 mm thick according to our caliper. This is still a good amount of foam underfoot to protect our feet from the harsh impact of landings while keeping us stable and low to the ground. 

Nike Free RN NN Heel stack
Test results
Free RN NN 25.6 mm
Average 33.6 mm
Compared to 300 running shoes
Number of shoes
7.6 mm
Heel stack
42.7 mm

Forefoot stack

We measured the forefoot stack to be 18.7 mm thick which is also quite a bit short of our current lab average. This also affords forefoot strikers a decent amount of impact dampening but a lot more ground feel. 

Nike Free RN NN Forefoot stack

For forefoot strikers who prefer having more protective foam at the forefoot, the Brooks Levitate Stealthfit 6 is another sock-like shoe that we recommend looking into. 

Test results
Free RN NN 18.7 mm
Average 24.9 mm
Compared to 300 running shoes
Number of shoes
7.6 mm
Forefoot stack
35.8 mm

Drop

The difference in our stack measurements leaves the Free RN NN with a heel drop of 6.9 mm, thus classifying it as a mid-drop shoe. This offset is quite versatile as it will suit the stride of most runners whether forefoot, midfoot, or heel striking. 

Nike Free RN NN Drop

For a better understanding of drop heights, check out this in-depth guide that thoroughly explores the matter. 

Test results
Free RN NN 6.9 mm
Average 8.7 mm
Compared to 300 running shoes
Number of shoes
-0.8 mm
Drop
16.1 mm

Insole thickness

Using our caliper again, we measured the Free RN NN's insole to be 5 mm thick. This is ever so slightly thicker than average and leaves us with a nice and cushy footbed to sink into during our landings in this shoe. 

Test results
Free RN NN 5.0 mm
Average 4.5 mm
Compared to 296 running shoes
Number of shoes
1.5 mm
Insole thickness
7.3 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

Pressing our durometer against the midsole yields a reading of 26 HA. While this is slightly firmer than average, it still provides a balanced level of cushioning to our landings. 

Nike Free RN NN duro mid

This somewhat firm nature means that the midsole is keen to retain its shape and has a pretty good rebound as our weight shifts forward in the shoe. As such, the midsole doesn't feel dull by any means. 

That said, while the shoe can handle quick paces, especially by virtue of its featherweight stature, it doesn't have the snappiness or springiness we expect from a speedy shoe that will crack PRs. We recommend looking into the similarly low-profile and sock-like Brooks Levitate Stealthfit 6 for those afflicted with a need for speed.

Test results
Free RN NN 26.0 HA
Average 21.4 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 228 running shoes
Number of shoes
8.5 HA
Midsole softness (soft to firm)
41.5 HA

Difference in midsole softness in cold

We placed the Free RN NN in our freezer to observe the effects of cold conditions on the midsole. After twenty minutes, we took another durometer reading of the midsole and found that it only became 10.1% firmer once appropriately chilled. As such, the Free RN NN's midsole is much more consistent than average which means that the shoe's ride won't be compromised by frigid weather. 

Test results
Free RN NN 10.1%
Average 25.6%
Compared to 227 running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Stability

Lateral stability test

The Free RN NN does very little to mitigate the lateral movements of our stride, making its ride not particularly stable. While this shouldn't be much of an issue for those with a neutral gait, we recommend that overpronators look into a shoe with more corrective features like the Nike Structure 25 or the Brooks Hyperion GTS to avoid injury. 

Torsional rigidity

The Free RN NN put up almost no resistance to our manual manipulations, with us basically able to wring the shoe out in our hands. This earns the shoe the lowest torsional rigidity score of 1 out of 5 on our subjective scale. As such, the shoe is able to contort and twist along with the natural movements of the foot which, while unstable, translates to an extremely comfy and forgiving ride when we are running on level roads. 

Test results
Free RN NN 1
Average 3.2
Compared to 279 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The heel is similarly pliable, with no structure to it apart from a pillow of padding that gives the rearfoot some shape. This also contributes to the shoe's barely-there sensation underfoot as it puts no pressure on our tendons and does nothing to mitigate lateral rolling of our heels. 

Test results
Free RN NN 1
Average 2.8
Compared to 263 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

We found the Free RN NN's midsole to be slightly wider than average at 115.9 mm wide at the forefoot. This gives us more than enough of a base for surefooted landings and toe-offs as forefoot strikers. 

Nike Free RN NN Midsole width in the forefoot
Test results
Free RN NN 115.9 mm
Average 113.7 mm
Compared to 301 running shoes
Number of shoes
100.5 mm
Midsole width in the forefoot
126.5 mm

Midsole width in the heel

Meanwhile, back at the heel, the Free RN NN's midsole is on par with our current lab average, measuring 90.3 mm wide according to our caliper. This also afforded heel strikers a good landing platform that shouldn't feel unsteady. 

Nike Free RN NN Midsole width in the heel
Test results
Free RN NN 90.3 mm
Average 90.4 mm
Compared to 301 running shoes
Number of shoes
74.9 mm
Midsole width in the heel
106.6 mm

Flexibility

Stiffness

We secured the Free RN NN to our workbench and found that only 6.2N of force is needed to bend the shoe 90 degrees. This is one of the most flexible results we've come across in the lab and means that a brisk breeze could essentially bend the shoe to the desired point. 

This further contributes to the shoe's natural feeling ride that really had us feeling like we were running around barefoot while testing this shoe as it puts up no resistance to the flexion of our foot throughout our gait. 

Nike Free RN NN flexi
Test results
Free RN NN 6.1N
Average 29.1N
We use an average of four tests. The video shows one of those tests.
Compared to 283 running shoes
Number of shoes
2.2N
Stiffness
94.4N

Difference in stiffness in cold

We also repeated the flex test after leaving the Free RN NN in our freezer for twenty minutes and found that it got 23.4% stiffer. However, it could become 200% and still be much more flexible than the average shoe at room temperature. As such, the Free RN NN will feel consistently flexible and forgiving on the foot all year round no matter how low the temperatures drop. The combination of the shoe's performances in our freezer tests plus its warm upper makes it an excellent wintertime companion. 

Test results
Free RN NN 23.4%
Average 36.2%
Compared to 283 running shoes
Number of shoes
0%
Difference in stiffness in cold
148%

Grip / Traction

Nike's approach with the Free RN NN's outsole is unorthodox. They minimized coverage as much as possible to save on weight, while also scoring the rubber and the midsole to form a very minimal tread pattern (as well as to facilitate bending easily as we saw in the previous section). This, surprisingly, provided us with good traction on asphalt roads where the outsole had an almost sandpaper-like quality. However, more slick or wet surfaces did cause us to wobble a bit during our test runs. 

Nike Free RN NN grip

Size and fit

Toebox width at the widest part

Using our caliper, we measured the Free RN NN's toebox to be 104.9 mm wide at its widest point. This is much wider than average and means that broad-footed runners will enjoy an accommodating and comfy fit while those with normal-width feet have a little wiggle room to spare. 

Runners with narrow feet, however, will definitely find this a little too roomy to achieve a secure lockdown at the forefoot. We recommend checking out the Brooks Glycerin Stealthfit 20 as a much more snug alternative. 

Nike Free RN NN Toebox width at the widest part
Test results
Free RN NN 104.9 mm
Average 98.4 mm
Compared to 301 running shoes
Number of shoes
89.5 mm
Toebox width at the widest part
109.1 mm

Toebox width at the big toe

The toebox tapers to 80.3 mm wide in the area around the big toe according to our caliper measurements. This is also wider than our current lab average and means that we have plenty of room to splay out naturally within the shoe without butting up against the walls and risking hotspots or blisters.

Nike Free RN NN Toebox width at the big toe
Test results
Free RN NN 80.3 mm
Average 78.2 mm
Compared to 175 running shoes
Number of shoes
60.4 mm
Toebox width at the big toe
92.5 mm

Tongue: gusset type

The Free RN NN's tongue is integrated into the upper as one solid piece, giving the shoe a sock-like fit. As such, we didn't have to worry about slippage and enjoyed a nice and snug lockdown with the shoe essentially wrapping itself around our foot and virtually disappearing from our minds as we started testing it. 

Nike Free RN NN Tongue: gusset type
Test results
Free RN NN Sock like

Comfort

Tongue padding

With no tongue per se, we measured the area of the upper above the instep and found it to be only 2 mm thick. As such, the laces still felt quite present across our instep once our foot was locked in and ready to go, however, it wasn't a source of great discomfort once we started running. 

Test results
Free RN NN 2.0 mm
Average 5.6 mm
Compared to 298 running shoes
Number of shoes
0.5 mm
Tongue padding
14.2 mm

Heel tab

With sock-like shoes notoriously difficult to put on, especially those from Nike, the Free RN NN has, fortunately, furnished us with not one but two finger loops. One at the and another at the top of the tongue. 

Nike Free RN NN Heel tab

Yanking on these two in tandem did make the shoe slightly easier to squeeze into/ 

Nike Free RN NN Heel tab 2
Test results
Free RN NN Finger loop

Removable insole

The insole is fully removable so replacing it with an aftermarket one or a custom orthotic for added arch support is possible if necessary. 

Nike Free RN NN Removable insole
Test results
Free RN NN Yes

Misc

Reflective elements

The Free RN NN features a little reflective streak at the lateral side of the toebox. While this provides at least a minimal level of nighttime visibility, we recommend using additional high-vis gear when going for nocturnal runs along dimly lit roads. 

Test results
Free RN NN Yes