Verdict from 18 experts and 5 user reviews

9 reasons to buy

  • Abundant cushioning: The TrailFly G300 Max impresses runners with its soft, “fat tire”-like G-Fly foam. It’s not as soft as in the Hoka Speedgoat but feels easy on the feet after hours of running.
  • Underfoot protection: There is no need for a rock plate as the foam “swallows stones and pebbles.”
  • Sticky grip: Featuring the high-end Graphene rubber, the shoe boasts tacky traction.
  • Road-to-trail: Those who took the shoe from asphalt and tarmac to the trails and rocky areas are surprised with its ability to adapt.
  • Stable platform: Having a noticeably wider base than most Inov-8 trail shoes adds to the stability on uneven terrain.
  • Comfortable upper: Very similar in design and feel to the TerraUltra G 270, it is soft and forgiving straight from the box. It’s also “nice and wide” in the toebox.
  • Lockdown: “Consistent without being restrictive,” that’s how reviewers describe the fit.
  • Innovative midfoot flex: A few trail goers took note of the deep cut in the outsole. They think it somewhat helps the shoe be more efficient and adaptive to the terrain.
  • Amply breathable: There mesh “breathes enough” to keep your feet comfortable.

2 reasons not to buy

  • Weight: “It is felt.” Several reviewers were disappointed that the declared 300 grams correspond to the US men’s size 8. The next size up is 1.3 oz (38 g) heavier.
  • Not a fast shoe: More than a few runners expressed that the cushion holds you back from speeding up, feeling “cumbersome and clumsy.”

Bottom line

The TrailFly G300 Max is the first max-cushioned trail shoe from Inov-8 that is considered a massive step forward for the brand. It soaks up all the advanced technologies to bring comfort for the long haul (think 100 milers). The shoe lives up to the hype and performs admirably for its higher price point. 

Tip: see the best trail running shoes.

Inov-8 TrailFly Ultra G 300 Max: long name, big deal

Inov-8 trail shoes have been associated with firmer, closer-to-the-ground, aggressive silhouettes. This time around, we get a high-stack (the highest in the brand's lineup, actually), softer, hybrid TrailFly.

The company takes a new approach to its collection of ultra running shoes, producing a well-cushioned option for hours of comfort.

What is it for?

  • Distance: unlimited
  • Pace: slow-to-moderate
  • Terrain: paved roads, hard-packed trails, rocky paths (NOT recommended for soft, muddy terrain)

What's to like about the TrailFly Ultra G 300 Max?

  • Better cushioning: Graphene-infused G-Fly foam is reported to have 25% higher energy return that lasts for dozens of miles at a time.
  • Added energy return from the insole: The Boomerang insole is claimed to be 40% more responsive than standard inserts.
  • Better outsole adaptability: A deep Adapter-Flex groove helps the heel and forefoot work independently for optimum foot movements on various terrain.
  • G-Grip: 50% more durable and stickier than regular rubber.
  • Secure lockdown: Thanks to the gusseted tongue and Adapter-Fit overlays.
  • Plenty of wiggle room: Marked 5/5 on Inov-8's Fit Scale, the shoe boasts a wide forefoot.

Inov-8 TrailFly Ultra G 300 Max vs. TerraUltra G 270

TerraUltra G 270 became a hit in 2020 and became a "trail shoe of the year" for many avid runners. Is TrailFly Ultra G 300 Max is worthy counterpart?

What’s the same?

  • G-Grip with 4 mm lugs
  • wide toebox (Fit Scale 5)
  • adapter-fit upper + gusseted tongue

What’s different?

  TrailFly G 300 TerraUltra G 270
Weight 300 g 270 g
Drop 6 mm 0 mm
Heel height 30 mm 12 mm
Cushioning softer, more impact protection, more long-distance comfort firmer, more grounded
Other benefits Adapter-Flex: 10-mm cut for underfoot maneuverability feels faster
Price $190 $160


How Inov-8 TrailFly Ultra G 300 Max ranks compared to all other shoes
Top 4% trail running shoes
All trail running shoes
Top 7% Inov-8 running shoes
All Inov-8 running shoes
Top 4% neutral running shoes
All neutral running shoes


The current trend of Inov-8 TrailFly Ultra G 300 Max.
Compare to another shoe:
Jens Jakob Andersen
Jens Jakob Andersen

Jens Jakob is a fan of short distances with a 5K PR at 15:58 minutes. Based on 35 million race results, he's among the fastest 0.2% runners. Jens Jakob previously owned a running store, when he was also a competitive runner. His work is regularly featured in The New York Times, Washington Post, BBC and the likes as well as peer-reviewed journals. Finally, he has been a guest on +30 podcasts on running.