Nike Free 4.0 Flyknit Review

Nike Free 4.0 Flyknit Review

Nike Free 4.0 Flyknit Review


With the flexibility and lightweight of past shoes in this model, the Nike Free 4.0 Flyknit’s comfort separates itself from its predecessors and even successors.  It offers the perfect balance of weight, heel-to-toe drop, flexibility and transition.

User Rating 5 (1 vote)

 Free 4.0 Flyknit- My Experience

Instead of feeling tight and narrow with a curved toe box, the Free 4.0 Flyknit now fits like a comfortable sock.  I’ll apologize ahead of time. I’m going to continue using these sock comparisons all review long. The feel is not too tight and my toes no longer feel squeezed.  Though I typically run in my lovely semi-cushioned shoes, I like to get in a good pair of minimalist type-shoes.  This is also another reason I like the Free 4.0 Flyknit specifically.  The heel to drop is only 6 mm, while the 5.0 is 7 mm, and the 3 sits at 4 mm.  It’s really at my perfect level in terms of drop.  I haven’t fully adapted to simply running minimalist shoes and this really accommodates to that.  This is probably because I switch up what I run in too much to do so.

Every time I put the Free 4.0 Flyknit on my feet, it creates a very nice and tight feeling.  The sock-liner is so snug and my heel locks in instantly.  The forefront stretches out a bit as not too squeeze in my toes.  That is one of the biggest differences with the 4.0 compared to the 3.0 and 5.0 models.  The toe box is a bit wider, and it fits my foot better.  I know Nike is known for being a more narrow shoe, so I would plan to continue to up-size just in case, if you have had to in many past Nike models.

Free 4.0 Flyknit Upper

The upper in the Free 4.0 Flyknit is probably the biggest change from previous models of the series. It is the first time a flyknit upper has been introduced.  It is a much more comfortable, stretched out mesh than past shoes.  Instead of feeling crammed, it really molds to your foot, similar to a thicker sock. That being said, the stretched out materials really create an amazing level of breathability. You should not have any issues even in the hot humidity. With the breathability is the shoe’s drainage. Its almost just as great as the breathability. Running in the rain with the Free 4.0 Flyknit shouldn’t cause any problems even for the long distance minimalist runners. The overall comfort of the upper from locking in your heels, having a nice tight feeling, and really giving the room your toes need. The stretchy mesh of the shoe doesn’t add to the weight to the shoes as they are a minimal 7.4 ounces in my size. (9D Men). I have yet to find a minimalist shoe that has an upper I can grade as high as the Free 4.0 FlyKnit.  Whether the Free 4.0 Flyknit is considered a minimalist shoe is under some debate.  I consider it to be so since the drop is smaller than most of my other running shoes.  Though I reckon that true minimalist runners will have a big disagreement with me

Free 4.0 Flyknit Outsole

This is really the one area of the Free 4.0 Flyknit some people have a knock on. Instead of being made really in one piece, the outsole is made out of several phylite pods that are supposed to make the shoe more flexible.  The Free 4.0 Flyknit has been in my running rotation for about 2 months now, which should lock up to 150 miles since I have several in my rotation at the moment. I have yet to see any issue in terms of the outsole degrading or causing any discomfort.  I have seen several reviews that knock the traction of the outsole since there are few pods near your toes to create traction.  I have not slipped on these shoes but I typically run on straight dry pavement, whether it be a sidewalk or street.  I might be a bit more concerned with running in these shoes if I planned to run up several more surfaces, especially wet ones, such as hills or trails.

Free 4.0 Flyknit Midsole

The midsole really goes well with the rest of the shoe but I wanted to bring it up because of the lace system more than anything else. The midsole is pretty minimal with some flex grooves to help multi-directional flexibility. Beyond all that is the laces. I feel like with the construction of this shoe and its midsole, the overall snug fit the shoe provides, I can use the laces in two different fashions. First, I can leave the laces nice and loose and the shoe really follows loosely for a lot of air. Second, when running hard,  I can tighten up the laces and the shoe really takes place and follows suit. It’s almost like changing settings on what level of snug you would like on your foot. Part of this is the midsole and upper, and the other is because its not a centered lacing system so there are not any focused pressure points from the lacing compared to most shoes

Nike Free 4.0 Flyknit – Socks or no?

I have been asked whether you need to wear socks while running in the Free 4.0 Flyknit or not…. To give an honest answer that would have to depend on the runner. I have seen many instances where people have run 20+ miles in these shoes without socks and without problem. I have also seen runners talk about an inconsistent brushing near the heel of the shoe. I think if you are used to running without socks, the chances are you will be able to do so in this shoe. I have done it a few times just to try it out. Personally, I just cannot get used to it, so typically I’ll wear very thin socks instead.

Who would I recommend the Nike Free 4.0 Flyknit to?

For those who love to run in minimalist-type shoes, this should really go well.  This shoe will probably be pretty profound if you are transitioning into minimalist shoes as well.  The shoe runs best on pavement if you ask me as wet trails may be a problem and the outsole construction may pick up more pebbles and rocks on off-terrain type of surfaces. I would recommend these to both short distance and long distance runners. For those not familiar to minimalist running, I might go try and find a pair to try on first.  Though this could start as a great transition into the minimalist shoe world.  If you try them on, see how it feels and walk a bit in them. Today in my current collection these are my favorite Nike shoes and right now the only minimalist type shoes in my rotation.

 Pros and Cons of Free 4.0 Flyknit



*Extremely Lightweight

*Flyknit upper creates ultimate comfort and feel

*Flexes well with the foot – similar to a sock


*Outsole durability concerns.  Outsole picks up small rocks

*Limited on which surfaces this shoe may be used for due to lack of traction