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Review: inov-8 Trailfly Ultra G 300 Max running shoe

Written by Fiona

April 09 2021

Running shoe brand inov-8 has launched the Trailfly Ultra G 300 Max running shoe. I have been testing for the past few weeks.

inov-8 terrafly ultra g 300 max review

inov-8 make a few claims:

  • 25% better energy return that lasts for longer
  • First max cushioned shoe that adapts & reacts to terrain
  • World’s toughest grip for the ultimate in trail traction.
  • Cushioned ultra running shoe with the world’s first graphene-enhanced foam.

Other features include:

inov-8 terrafly ultra g 300 max review
inov-8 terrafly ultra g 300 max review

My review: inov-8 Trailfly Ultra G 300 Max running shoe

The shoe is more cushioned than any other inov-8 trail shoe that I can recall. They have made more cushioned road shoes before, but usually the trail shoe versions are non-cushioned and fairly unforgiving. They offer excellent “ground feel” and many people love inov-8 for this.

I have found most inov-8 trail and hill shoes to offer great grip and the lack of cushioning is not a major issue when you are running on softer ground, such as hills and mud, but it can be a bit hard going when on harder-packed trails.

The problem with off-road running is that it usually includes a mix of terrain. Most runs I do will have softer, muddier hill paths, forest tracks, some tarmac and then a mix of the above.

inov-8 state that the inov-8 Trailfly Ultra G 300 Max running shoe is for “hard and rocky paths and trails, and road”.

inov-8 terrafly ultra g 300 max review
inov-8 terrafly ultra g 300 max review

I have to say that it has felt like a breath of fresh air running in these shoes. Perhaps my old bones and joints prefer a bit more cushioning underfoot than they used to, or maybe it’s the mix of terrain that I now tend to run on, but the cushioning is noticeable and welcomed.

I have enjoyed running in different conditions, too, including wet, dry and snow – and on mud, grass, rocks, trails, paths, hills and tarmac. I feel like the shoes are game-changer because they are suitable for so many different types of terrain.

Note that they are not going to give you the best grip on steep wet and muddy terrain. You will be better off with one of the inov-8 shoes that are meant specifically for this type of terrain. Also, they are not as cushioned as other shoes, such as those made by Hokla One One or the other favourite of mine, the Dynafit Ultra 100 shoe.

But for general all-round use on a range of off-road terrain they are great.

inov-8 terrafly ultra g 300 max review

The various claims are difficult to prove/understand at times.

‘25% better energy return that lasts for longer’

inov-8 also states that graphene-enhanced G-FLY cushioned foam is used for the first time on the Trailfly Ultra G 300. It uses a blend of lightweight elements, including graphene, Thermo PolyUrethane (TPU), and EVA (Ethylene-Vinyl Acetate), all of which possess outstanding elasticity. 

Tests show the foam is more resistant to wear, and thus retains its cushioned thickness and optimum levels of snappy energy return for longer. Runners can feel faster and fresher over greater distances. 

G-FLY gives 25% more energy return. Laboratory tests show that even when the foam is aged to mimic extensive use, it still delivers more energy return than some unaged foams. Athletes testing the foam said it was still performing after 1,200km – double the industry standard.

The depth of the foam is 25mm at the heel and 19mm at the forefoot. When combined with the outsole lugs (4mm) and base rubber (1mm), this makes the full stack height (minus the insole) to be 30mm at the heel and 24mm at the forefoot. It’s our deepest ever foam cushioning.

The hexagonal shapes on the outer of the foam represent the molecular honeycomb shape of Graphene. 

I asked inov-8, 25% better than what? They said: “25% greater energy return in the G-FLY foam versus widely-used EVA foam.”This is fair enough. I am just not sure I can judge “energy return” and percentages thereof. However, I can say the shoe feels more cushioned and comfortable to run in than other inov-8 trail shoes on certain terrain.

‘First max cushioned shoe that adapts & reacts to terrain’

inov-8 states: The shoe has an “ADAPTER-FLEX groove”. This is basically a more flexible groove across the centre area of the sole and it does allow for good flex (if this is something you like in a trail shoe).

“ADAPTER-FLEX is a revolutionary 10mm deep groove that makes this the only max cushioned trail shoe that adapts, reacts and moulds to uneven terrain for a responsive ride. 

It frees the stacked midsole of rigidity so it can work in harmony with the foot, promoting high levels of flex, mobility and natural movement. Runners can feel connected to the trail. A unique proposition set against the current trend of underfoot carbon plates. 

The flex sits under the midfoot to align with the oblique midtarsal joint axis. This joint’s function is to allow the forefoot to turn inwards or outwards without influencing the same motions in the heel. By having a flex groove under it, the joint is free to do its job. This helps the foot – and shoe – adapt, react and mould to uneven terrain or sudden changes in the trail, while the heel can stay straight.

I also don’t really know what this means. Iasked inov-8. They said: “The ADPATER-FLEX groove allows you to feel connected to the trail and adapt quickly to changes in uneven terrain (basically ground feel). Other max cushioned shoes do not give you any kind of ground feel.”

I guess it is inov-8’s way of saying this is a cushioned shoe, yet it also has attributes that inov-8 are acclaimed for, such as offering good traction on the trails.

I do think that despite the thicker sole and cushioning, the shoes give great grip and flex underfoot and they are great for running on a range of surfaces. The flex feels just about right to me.

‘World’s toughest grip for the ultimate in trail traction’

Graphene is certainly claimed to be the world’s toughest material, offering durability and flexibility. inov-8 are also well known for making running shoes with great grip.

Further, inov-8 states:  By infusing graphene into our rubber were able to remove the previous compromise between a soft rubber that grips well but wears down quicker and a hard rubber that is more durable but not as grippy. The graphene imparts its incredible properties to deliver a rubber with both insane sticky traction and incredible durability, no compromise. We call this the world’s toughest grip.

The rubber is scientifically proven to be 50% stronger, 50% more elastic and 50% harder wearing than standard rubber outsoles.

In my opinion, the issue is that the soles might well outlast the uppers and so, in the end, there is not a great deal of use to a sole that goes on and on yet the upper falls apart. Only time will tell if the upper can last as long as the sole. I usually find the upper gives up before the sole in most of my trail shoes.

More points: inov-8 Trailfly Ultra G 300 Max running shoe

The fit is good for even a skinny foot like mine. My previous issues of the heel cuff hitting the lower part of my ankle bone has gone. I feel like the upper design is more similar to inov-8 trail shoes of old.

Water does get in, but it quickly escapes, too.

The price is rather eye-watering. I was sent a pair to test without charge so I didn’t need to pay £170. I get that there is a lot of technology in these shoes but I think that many people will stall at paying such a hefty price for trail shoes.

Saying all this, I have been very happily running in the inov-8 Trailfly Ultra G 300 Max running shoe for almost all of my runs recently so I am getting good wear from them

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