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Trail Running Shoes • March 26, 2021

Inov-8 TrailFly Ultra G 300 Performance Review

inov-8 trailfly 300 - feature

What You Need To Know

  • Weighs 10.6 oz. (300 g) for a US M8.0
  • Utilizes all-new, ultra-durable, high-cushion and responsive foam made in part with inov-8’s proprietary graphene
  • Segmented graphene outsole with aggressive lugs provides ample traction and movement, as well as unparalleled durability
  • Beware of the thin tongue and abrasion potential

TAYLOR: UK-based inov-8 (we’ll forgive them for the all-lowercase name) is one of the hardest-hitting running brands out there with way too little trail cred. Their name is literally derived from their desire to constantly evolve with top-of-the-line performance running equipment. Take our 2020 BIG (Best in Gear) Awards Trail Shoe of the Year: the Terra Ultra G-270. That thing cleaned house with its incredibly rugged design and sticky-yet-durable graphene outsole in a lightweight package!

So here’s inov-8 stepping up to the plate again. This time, they’re swinging for the fences. Max cushion, an accommodating fit, adaptability, and durability all come together in the all new TrailFly Ultra G 300 Max (the ‘300’ is a denotation of the weight, in grams).

For a company that usually prioritizes foot security and connection to the earth below, this is certainly a different take on the traditional max cushion shoe. The TrailFly’s highlight is the newest graphene-enhanced midsole foam. Previously, graphene was only used in the inov-8 outsoles.

A quick graphene primer for the uninformed– it’s a kind of wonder material that boasts incredible strength (200 times stronger than steel), flexibility, and in a very small package. Essentially, it provides the stickiness of a grippy outsole, but doesn’t sacrifice durability (with most outsole materials, having more of one is a tradeoff with the other). With graphene, you can have your mud cake, and eat it too. Bonus points that inov-8 owns the patent rights to graphene (which they developed in conjunction with the University of Manchester), so nobody will be swiping it anytime soon.

Inov-8 has proven graphene’s worth in the G outsole alone. But is pumping it in the midsole too far-fetched? That has been my question from the start.

According to inov-8, their new graphene-enhanced cushion foam, G-FLY, delivers 25% greater energy return than traditional foams, while remaining far more resistant to compressive wear. The reportedly have tests showing the foam still performing well after 1,200 km in the shoe. If true, I’m on board.

That said, as I pulled these out of their package for the first time, I chuckled because of the TrailFly’s weight (it seemed a bit heavier than the advertised 300 g); however, I hadn’t slipped the things on yet, and I certainly hadn’t gotten on some trails. Which is, of course, where the magic happens. Let’s see how they turned out.


The Good

TAYLOR: I’ll start with what is usually a parting point for many runners who consider inov-8 shoes. In the past, their shoes have been narrow, to say the least. However, just like the post-COVID economy, things are opening up for inov-8. The fit here is truly average width. I’m going to say these are definitely the widest fitting shoe I’ve worn from inov-8, even though they claim it’s the same forefoot width as the Terra Ultra G 270 (I had zero issues with fit). I’m not saying that Widefoot Jarrett is going to be able to slip into these like the princess stepsister that he is, but the “average” runner will. More room also gives a better setting for your feet in those long days on the trail. So, give it a chance!

Usually a wider fit means less foot security, but not in the TrailFly’s case. Inov-8 is world-renowned for its secure fit and they maintain it even with their widest fitting shoes. It is very similar (maybe identical) to the more stiff but durable mesh from last year’s Terra Ultra. A racer-style thin tongue also mirrors that of the Terra Ultra. The mesh breathes enough to keep your feet comfortable and initiate drying after stopping through slush. Trust me.

Overlays can be found through the midfoot to add more support and maintain the secure fit. They also can be found throughout the lacing system, as well as other strategic places throughout the lateral and medial sides of the shoe, before swinging out over the hefty toe bumper. With a shoe that claims a lifespan of double or triple the length of the average shoe, these overlays will come in handy to keep the shoe’s structure on the topside.

Time for the goods. That “pie-in-the-sky stuff”. The material of lore … graphene. I mean, it’s the whole basis of this shoe.

inov-8 graphene

Photo courtesy of inov-8

Graphene Grip is Inov-8’s exclusive outsole that fuses graphene into the rubber. This is the Muhammad Ali of outsoles. It’s the pound-for-pound king for both grip and durability. I have pairs of inov-8 shoes with over 100 miles that look barely scathed from underneath. The 4 mm lugs of the TrailFly clawed into dirt, held steady on rock, stuck to it over wet/packed snow sections, and more. Also, since the lugs were moderately deep, the curvature of the outsole allowed the TrailFly to also transition smoothly on pavement.

The “big” story with the TrailFly is the midsole. Not only is it out of the norm for invo-8 to make a truly maximal shoe (most of their shoes are zero-drop, this has a 30mm – 24mm stack), but this midsole is quite different from most anything I have run in. Of course, graphene is the highlighted material in the midsole foam. Durability and protection are easily achieved.

The feel is moderately soft and somewhat rubbery. The closest resemblance is the foam combo in La Sportiva’s Jackal – just a lot more in this case. I never felt a soft fall into the clouds feeling like you would in shoes like the New Balance Fresh Foam More Trail V1, Hoka Stinson, or ASICS Trabuco Max. G-fly compressed slightly and responded with a jab of energy back. As mentioned above, the outsole is slightly curved which gives a hyper smooth foot roll of the foot.

Within the outsole are a series of grooves. The highlighted one, called ADAPTER-FLEX, slices through the midfoot width-wise. I mean, it almost looks like you’re wearing a boot. It’s a 10mm crevasse that allows the foot to rotate and adapt naturally on any varied terrain. I’m totally sold on it. Even with the high stack my foot transitioned smoothly on moderately technical terrain over rocks, roots, and oddly packed snow. This is not a typical sensation in these higher stacked shoes and is usually a huge limiting factor. Not in the TrailFly though. The forefoot showcases more grooves that run lengthwise underneath the metatarsals offering even more adaptability over a variety of terrain. Many Altra shoes utilize similar forefoot grooves.

Along with the extra cushion, a wider-than-typical base was utilized for extra natural stability. I always think of the Hoka Stinson and Altra Olympus when it comes to these matters; stability doesn’t have to come from a post. The wider base worked wonderfully here in the TrailF

Shop Trailfly Ultra – Men Shop Trailfly Ultra – Women

ly to further assist in keeping the high stack standing.

Last thing – shout-out for the custom Believe in the Run monogram on the tongue. Was pretty stoked to see that.

Shop Trailfly Ultra – Men Shop Trailfly Ultra – Women


The Bad

TAYLOR: Weight is low-hanging fruit when being nit-picky with modern shoes. When my size 10.5 trail shoes start to hit the 12-ounce mark, that’s my sign to be a little extra critical because so often it is very unnecessary. Reach into the 13 ounces per shoe and that’s a whole different category of impractical.

The TrailFly Ultra G 300 Max sits like a sledgehammer in that last assortment of shoes: 13.2 ounces was the weight for one shoe. If conditions are at all inclement, you will feel every ounce of that. It’s very uncharacteristic of the usual light and fast inov-8 shoes that I’ve tested in the past. I was surprised at how much mine weighed, considering the shoe’s naming convention would suggest it should only weigh 300 grams (10.6 ounces) for a traditional US men’s 9.0 sample size. However, that’s what it weighs for a US men’s 8.0. Honestly, it’s an issue I have with putting the weight in the name. It’s totally subjective to each person’s foot and it doesn’t seem to align with the standard sizing of most shoe companies.

Thankfully there’s a lot more going for the TrailFly so they do not feel like complete bricks underfoot.

As mentioned before, the upper and tongue are pretty identical to the Terra Ultra G 270. The tongue is paper-thin while the upper’s mesh is more on the durable/rough side. Those aspects combined with a very sparsely padded collar caused some issues for me.

Right at the juncture of the top lacing eyelet and the collar, it is very tough. The tongue is thin so it does not protect your ankle from abrasion by this piece of the collar. I’m making it sound a little worse than it is, but after my first 10-miler in the shoe, my ankle was, well – bleeding – and obviously uncomfortable from the constant rubbing. Disclaimer: this was only on my right foot, so there could be some anatomical differences coming into play here, but it still sucked! It bothered enough that I would have to take days between runs in the TrailFly. If I can’t go 10 miles without discomfort, how can I take this shoe around the mountains for hundreds of miles!?

I’d also like to see some deviation from the neon lime green that seems to have become their signature. The trail space is finally catching up to the road space in design, and some more modern color palettes would do this thing wonders.

Shop Trailfly Ultra – Men Shop Trailfly Ultra – Women inov-8 trailfly 300 - tongue

Inov-8 TrailFly Ultra G 300 Conclusion

TAYLOR: Innovation is Inov-8’s trump card. The new Traifly Ultra G 300 Max is certainly a different take on the maximal shoe craze and a different take for the company itself. Its new carbon-enhanced G-fly foam leads the way with an incredibly durable, responsive, smooth, and protective ride on trails and smoother surfaces. Unique flex grooves allow for it to be highly adaptable to rough terrain without tipping the canoe. It’s really impressive for such a high-stack shoe. 

Its kryptonite is very obvious too. The weight is too obvious not to mention and look out for the downfalls of a stiff protective upper. Both could stop your journey of an ultra before it even begins.

As always, I’d buy a box of chocolates for the Graphene Grip underneath. I love it. It’ll be the best grip you can find over nearly any surface. My hopes are that the TrailFly is a ploy, just like the Hoka TenNine, to showcase a new technology to an extreme. Then, future iterations with similar technology won’t be as much of a shock and blow our socks off. Inov-8 is onto something here as they curate the space for shoes that could keep their integrity for double or triple the life of a typical running shoe. Not only is that a bonus for the pocket, it’s also beneficial for sustainability. For $190 this could be an absolute steal when considering cost per mile, or it could be an expensive one-and-done. 

You can pick up the inov-8 TrailFly Ultra G 300 Max for $190 on April 8 by using the shop links below.

Shop Trailfly Ultra – Men Shop Trailfly Ultra – Women
inov-8 trail shoe

Photo courtesy of inov-8


Have something to say? Leave a Comment

  1. Landry says:

    These shoes are worth every penny of $190.. with that said.. they have some competitors but Inov-8 knocked it out of the park imo. It’s not a min stack shoe or lightweight but a very effective hybrid. Fits the bill for me.

  2. Jose Bon says:

    I love the shoes but the super stiff collar gave an ankle pain so I decided no use it anymore. I had flat feet and my ankle bone suffer with the same issue.

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