Gear Review: Inov-8 Trailfly Ultra G 300 Max

Over the past few years, Inov-8 has earned itself a reputation for creating some of the most rugged trail runners and hiking boots on the market. The company achieved this through the use of wonder-material graphene (read more about graphene and thru-hiking here) in the soles of its shoes. We reviewed the Terraultra G 270s last year, and they’ve been a favorite of ours ever since, making it onto our list of the top trail runners of 2021.

This year, Inov-8 has taken a different path of innovation, using graphene-infused foam to improve cushion and keep you on trail longer. The result: a trail runner that could last over 1000 miles. Introducing the Inov-8 Trailfly Ultra G 300 Max.

Inov-8 Trailfly Ultra G 300 Max At-a-Glance

inov-8 trailfly

Image courtesy of Inov-8

MSRP: $190
Weight: 10.58 ounces (300 grams) per shoe
Sole Composition: Graphene Grip rubber composite
Drop: 6mm
Overall stack height: 25mm at the heel to 19mm in the toe
Color option: Green

Circumstances of Use

As durability is one of the key selling points of the Inov-8 Trailfly, we didn’t start penning this review until the shoes had notched up over 500 miles. I primarily tested them on a multi-week long section of the South West Coast Path in the UK with a fully loaded pack (roughly 30 pounds at the start of the hike) For reference, I’m a 6’4” bloke weighing about 190 pounds. In other words, the cushion has been tested aggressively, so you should get even better mileage than I did.

In addition to this, these shoes have become my daily driver for the last few months in order to get the most miles on them for the review. They’ve seen all types of British weather, including the wettest May on record, and have typically hiked on compact dirt/muddy trails, though they’ve also been used on tarmac.

Who is the Inov-8 Trailfly Ultra G 300 Max designed for?

inov-8 trailfly

If you typically like to hike in a well-cushioned shoe, such as the Hoka One One Speedgoats, then I’d recommend giving these a shot. The shoe is designed for ultrarunners, with emphasis on improving the cushion of the ride – and this is immediately noticeable. As someone whose plantar fasciitis often flares up, I also loved how well these shoes absorbed the trail. Where these shoes excel from the competition is that not only are they cushioned, but they are responsive to the trail thanks to the under-foot Adapter-Flex groove, which separates the heel and the forefoot.

These shoes are also easier to get used to when coming from a traditional trainer as they are not zero drop shoes (read more about zero drop vs. high drop shoes here). As such, they would be a great companion for someone looking for a supportive, durable, and extremely comfortable ride.

The Big Features

The Midsole: This shoe offers maximum cushion – a big departure from Inov-8’s normal, which emphasizes low profile, lightweight designs with excellent ground feel. The new graphene-enhanced cushioned foam is what Inov-8 calls its G-FLY technology and provides two features: energy return and cushion.

Having gotten used to minimalist shoes, these shoes are immediately noticeable in just how springy they feel. I love the shoe and find myself less worried about the impact of a hard trail or going downhill than I typically am. In terms of energy return, I can’t accurately say if I am getting the 25% extra energy return Inov-8 promises compared to other models. However, they do spring back into shape and I haven’t noticed this deteriorate dramatically over the 500 miles these shoes have already done. The comfy insoles (called the boomerang inners) also help improve the comfort of the ride.

The Adapter-Flex ridge. Image courtesy of Inov-8.

The Adapter-Flex: This underrated feature means that the shoe has a groove in the center area of the shoe, allowing it to flex. This means that the front and back of the shoe can move independently, giving you a responsive ride that can adapt to the terrain. This means that even though you are wearing a super cushioned shoe, the grip and reactiveness of the shoe isn’t compromised.

Graphene Grip Sole: Inov-8 is still the only sportswear company to utilize this graphene-rubber mix, which improves the durability of the shoe versus a standard trail runner. This is more than just marketing hype — my last pair of Inov-8s are still going strong. While the lugs have worn down in places, they still perform well on compact trails and roads.

A lightweight upper with a strong toecap: the upper is pretty much identical to that of the TERRAULTRA G 270s I reviewed (and loved) last year. The rubber cap has been improved to provide even more rigidity helping keep your toenails intact. The high stack height combined with a rubbery coating along the bottom part of the upper means these shoes are less likely to flood on the occasional puddle. When they did flood, I found that they dried out quickly due to the breathable yet super strong mesh used here.

Wide fit: The Trailfly is the widest fit Inov-8 offers, yet you feel secure in your fitting. The shape of the front of the shoe has changed slightly from the Terraultras, and I did find that, whilst most of the shoe was wide enough, on the front outer edges it pushed my pinky toe into the rest of my toes. I’d have preferred if they let the toe box run a little wider at the front of the foot to let my toes splay a little more, similar to what you get with an Altra.

What are the differences between the Inov-8 Trailfly and the Terra Ultra G 270s?

The TerraUltra G 270s on the left, the Inov-8 Trailfly G 300s on the right.

These two shoes are built for two different preferences. Both benefit from amazing grip, high durability and breathability. Although they are very similar, I think it’ll come down to this distinction: if you want maximum comfort and therefore don’t mind a higher ride, the Trailfly is for you. If you want a shoe that is zero drop, lighter in weight, and you want to feel more connected with the trail you are on, the Terraultra G 270 is your pick.

Inov-8 Trailfly Pros

inov-8 trailfly

Cushion/responsiveness: These shoes are one of the comfiest shoes I’ve ever worn on a trail. The 25mm stack height of graphene-enhanced foam has resulted in a long-lasting absorption of the trail beneath you, and a bounce that didn’t deteriorate over the 500 miles I’ve put on these shoes so far. I have no doubt these shoes will continue to perform great as they rack up 1000+ miles. I’m of the firm belief that comfort needs to be the number one thing to look for in a shoe that is going to be your companion for hundreds of miles on a long-distance trail. This shoe performs excellently here.

I used to tend to stay away from max cushioned shoes as I used to find they made me more clumsy than I naturally already am. These shoes overcome that with the Adapter-Flex technology. Looking at this shoe from the bottom, you’d be forgiven for mistaking these for a rugged hiking boot. That said, the flexibility of the shoe means they respond well to trail conditions and I didn’t get that detached feeling that I’ve had previously.

inov-8 trailfly

Durability/environmental impact: As with all the Inov-8s that we’ve reviewed, the graphene soles continue to blow any other competitors out of the water in terms of durability. I’ve still got the lugs on my Terra Ultras after 500 miles. The only place where there are any real signs of wear on the midsole (the foamy middle bit) is around the outside of the heel due to a slight overpronation in my gait.

The Graphene Grip, Gfly midsole, and strong upper means you’ll likely get more miles out of this shoe on trail than any other. This means that over the course of a thru-hike, you may be able to get away with buying 1-2 fewer pairs, saving you time and helping reduce your impact on the environment. In addition, all Inov-8 shoes are vegan, if that is something you look for.

inov-8 trailfly

A great upper: The uppers on these shoes are breathable, lightweight, and are not prone to flooding thanks to a high stack height and rubber coating. I have yet to see any signs of wear on the tops of these shoes—or on the tops of any pair of Inov-8s I’ve tested previously, for that matter.

Inov-8 Trailfly Cons

Price: a pair of the Trailflys will set you back about $190, which is a really steep initial cost at almost double that of a standard trainer. Although the upfront cost may be more, due to their increased durability, it may end up working out cheaper than buying numerous pairs of a less expensive shoe. A 30-day returns guarantee is also a good way to make sure the almost $200 dollars you’ve spent isn’t a waste.

Tongue: I mentioned the minimalist tongue when I reviewed the Terraulta G 270s, and unfortunately these are no different. I found that because the tongue is so thin, I sometimes don’t tie the shoe up as tight as I’d like as this puts too much pressure on the top of my foot. I still think that Inov-8 could go with a bit more padding here – especially as this shoe is supposed to be about comfort. I imagine the decision was taken to keep weight down.

The Neon Green Color: I know color is a personal preference, but there is no getting around the fact that these shoes are intensely bright. I think Inov-8 is doing this to catch people’s attention, but it gives off a vibe similar to that of the first electric cars before Tesla came along. The reason this is important to me is that I tend to use my shoes first for hiking/walking and then retire them into shoes I wear more generally when they reach the end of their running/hiking life. I can’t do that with these green monsters. While testing these, I got a lot of comments from people I met up with. I’m hoping that Inov-8 creates a version in a more neutral color so that they don’t just look at home on the ultra circuit.


Final Thoughts

All around, these shoes are great. They will outlast pretty much any of the competition and will feel great doing so thanks to the cushioned yet responsive ride the new innovations in this shoe provides. While they have a steep initial price tag, you’ll quickly earn that back by not needing to swap out your shoes as often — a great thing for you and the planet.

Shop the Inov-8 Terraultra G 270

Comparable Shoes

Hoka One One Speedgoat 4

MSRP: $145
Weight: 10 ounces
Cushion: Maximum
Stack height: 32-28mm
Drop: 4mm

Brooks Caldera 4 

MSRP: $140
Weight: 8.9 ounces
Cushion: Maximum
Stack height: 31-27mm
Drop: 4mm

Topo Ultraventure Pro 

MSRP: $145
Weight: 8.2 ounces
Cushion: Maximum
Stack height: 30-25mm
Drop: 5mm

Disclaimer: the Inov-8 Trailfly Ultra G 300 Max was donated for purpose of review.

Affiliate Disclosure

This website contains affiliate links, which means The Trek may receive a percentage of any product or service you purchase using the links in the articles or advertisements. The buyer pays the same price as they would otherwise, and your purchase helps to support The Trek's ongoing goal to serve you quality backpacking advice and information. Thanks for your support!

To learn more, please visit the About This Site page.

Comments 1

What Do You Think?