Article by Kurt Biesemans and Sam Winebaum
Inov8 Trailfly Max ( £150 / $170 / €170)
Introduction
Kurt: The Inov-8 TrailFly Max is the most cushioned addition to the refreshed TrailFly series, which now features four distinct models tailored for runners who crave a natural ride over hard-packed terrain.
What sets the TrailFly series apart is its use of Graphene-enhanced rubber, a groundbreaking compound that delivers outstanding grip and durability. The outsole features 4mm lugs that bite confidently into the trail, offering reliable traction in a variety of conditions.
The shoe is built around a new NATURALFIT™ shape to lock the foot securely at the heel and midfoot while widening at the forefoot, allowing the toes to splay naturally for enhanced stability and comfort over long distances.
Taking over from the much-loved TrailFly Ultra G 300 Max, the TrailFly Max goes big on cushion without compromising ground feel. It’s loaded with a generous stack of FLYSPEED™ PRO foam, a new lightweight midsole compound that delivers plush cushioning and impressive energy return with every stride. The result? A max-cushioned, yet naturally responsive ride designed to keep you feeling fresh during long training days and ultra-distance adventures on firmer ground.
Pros:
Flat at the ground profile is very stable: Kurt, Sam
- Very protective underfoot: Sam
Supercritical nitrogen infused EVA midsole+ TPu beads Boomerang insole is lively and bouncy in a muted solid way: Kurt, Sam
Boomerang insole provides grippy, non-slip surface minimizing internal foot movement: Sam, Kurt
- Robust shoe: Kurt
- Great grip and quiet ride from G-Grip outsole (on the soft side comparatively): Sam, Kurt
Cons:
Flat at the ground profile with no rocker does not aspire to speed: Sam
Extensive robust toe bumper reaches too far over the toes, improves with break-in: Sam
Lacks lateral support in ankle region, non rigid low heel counter: Kurt/Sam
10g weight difference between right and left shoe: Sam
Stats
Approx. Weight: men's 9.75 oz / 276g US9
Sample Weights: men’s 10.8 oz /306g US10/EUR43, 270g / 9.52 oz (average of 275g and 265g) US8.5
Stack Height: men’s 35 mm heel / 29 mm forefoot (6mm drop spec)
Platform Width: 85 mm heel / 60mm midfoot / 110mm forefoot
First Impressions, Fit and Upper
Kurt: The shoe sports a modern look, enhanced by colorful accents on both the toe bumper and the overlays. It features Inov-8’s NaturalFit—a foot-shaped design first introduced in 2024 and now standard across their range. The shoe is relatively narrow in the heel and midfoot (80mm), but it widens in the toe area, allowing for natural toe splay. For my foot shape, the regular version fits well, but runners with a broader forefoot will appreciate the wide version, which offers additional room in the toe box.
The upper is soft and made from a breathable air mesh material.
MET-CRADLE overlays extend from the midfoot all the way around the heel.
Combined with the natural foot-shaped design, they aim to deliver a locked-in, secure feel that gently pulls the foot into place from the midfoot to the heel.
The tongue is gusseted and has just the right amount of padding.
I received a US 10, which corresponds to a EU 43. I normally wear a EU 44, but so far, the fit hasn't been an issue. I'm not entirely sure how going up one EU size would affect the overall feel.
Sam: Agreeing with Kurt the Max has a cheerful modern design with the yellow overlays highlighting the toe bumper and lace up towards the rear support.
The Air Mesh is thin and very pliable and lined with a soft material towards the front while remaining very debris proof with support provided by extensive pliable overlays and a narrow thin and stretchy gusset strap. Midfoot hold is superb without overdoing it
The heel counter is non rigid, less rigid than most trail shoe heel counters, with the ankle collars low and the foot at the rear not seated very deeply into the midsole.
When combined with the not particularly deeply cushioned or firm collars, the firm outsole and relatively soft midsole foam the rear of the upper is a bit too relaxed for technical trail uses. Not loose per say but the ankle is a bit more mobile than I would prefer. No issues on most smoother terrain but noticed on rougher terrain making me more tentative there.
The toe box clearly has the anatomical “Natural” shape called out in the Inov-8 description with a wide version available.
When I first tried on my true to size US8.5 / EU 41.5 there was noticeable pressure on my dodgy big toe from the toe bumper which, while not particularly rigid, wraps way over the top of the toes.
It took a few runs for the fine Boomerang insole to pack in just enough and the upper to stretch. Now things are fine but still a bit “top” cramped upfront.
I think the toe bumper could be reduced in over the top of foot coverage with no harm to either hold or protection. Otherwise, the fit is true to size upfront for my narrow to medium shape feet if on the snug performance side. I wonder if I might have been better off with the wide version.
Midsole & Platform
Kurt: The Inov8 TrailFly Max sets itself apart from the rest of the TrailFly line-up thanks to one standout feature: the midsole. At the heart of this trail machine lies Inov-8’s new FlySpeed Pro foam, a nitrogen-infused, supercritical EVA that delivers a compelling balance between responsive cushioning and precise ground feel. This foam is also shared with the new lower stack TrailFly Zero, zero drop model (RTR Review soon).
With a stack height of 35mm in the heel and 29mm in the forefoot, the TrailFly Max offers a moderate 6mm drop, making it well-suited for long distances where comfort and control must coexist.
To further enhance underfoot feel, Inov-8 integrates its signature 6mm Boomerang insole, constructed from expanded TPU beads. This high-rebound insole not only provides superior energy return and less water absorption compared to standard insoles but also offers anti-slip properties to keep your foot securely in place — a subtle but meaningful addition.
The synergy between the FlySpeed Pro midsole and Boomerang insole makes it clear why Inov8 positions the TrailFly Max as its go-to choice for ultra-distance and technical trail running.
In terms of the platform, the TrailFly Max leans toward the narrower side, with a heel width of 85mm, midfoot of 60mm, and a forefoot of 110mm.
Sam: Kurt describes the midsole and platform well. The FlySpeed Pro foam is protective, deeply cushioned and moderately reactive while also remaining stable. While dense in feel (good for a trail shoe) it is also lively with a measured gradual rebound/ bounce sensation characteristic of supercritical EVA which Pro foam is. No brick hard traditional EVA feel here or for that matter also not the somewhat squishy slow reacting feel of EVA blends.
The supercritical EVA also has a weight advantage over regular EVA, weight. At 270g/ 9.52 oz in my US8.5 sample with a stout full coverage 4mm lug outsole and 35mm heel / 29 mm forefoot stack height we are very reasonable in weight.
The TraiFly midsole is nicely reactive on smoother terrain and very protective and stable on more technical terrain and, despite the big stack height, there is more than adequate trail feel and front agility.
Outsole
Hard-wearing, tacky rubber infused with the world’s strongest material – Graphene – makes up the outsole. The 4mm long multi-directional lugs not only cut through loose trails and remain super-durable but also give improved grip in wet conditions. Underfoot flex grooves further enhance the agile, natural feel. Disclaimer: At the time of writing I was not able to test the shoe in muddy conditions.
Sam: I was able to run the Max on all kinds of surfaces from moderately technical trails, some mud and even pavement and gravel. Grip was excellent everywhere. The Trailfly is moderately flexible thanks to its ball of the foot Meta Flex groove.
The full rubber coverage stabilizes what is a narrow 60mm forefoot platform just fine, although I did find my midfoot at the ground occasionally “catching” obstacles more than I would like. Lower profile less aggressive lugs in that area might be a worthwhile improvement. While removing midfoot rubber could lighten the shoe, I think the midfoot platform might then have to be widened to keep things stable.
Ride, Conclusions and Recommendations
Kurt: Personally, I love this in-between category that seeks a balance between cushioning and ground contact and articularly on technical trails, where I value reliable ground contact just as much as cushioning. That combination gives me the confidence to move decisively, helping reduce the risk of missteps and injury.
In terms of feel, it slots in somewhere between the plush comfort of the Hoka Mafate Speed 4 or the ASICS Trabuco Max 4, and the propulsive speed of carbon-plated shoes like the Hoka Tecton X3.
Personally, I felt well-secured at the midfoot, but not at all in the heel. The heel collar, in my opinion, lacks sufficient support and sits quite low below the ankle, which limits lateral stability. Even with a runner’s loop lacing technique, I didn’t achieve a strong heel lock.
Due to the lack of lateral support, the Inov8 TrailFly Max may be better suited for smoother and flatter trails. Looking at the outsole and lungs it might perform outstanding in the mud.
Kurt’s score: 7.95/10
Ride (30%): 8.5
Fit (30%): 6.5 - Lack of heel stability
Value (10%): 8.5
Style (5%): 9
Traction (15%): 9
Rock protection (10%): 8
😊😊😊Sam: The Trailfly is a solid all around trail runner with plenty of deep and nicely reactive cushioning to extend its uses to ultra distances while having the outsole coverage and graphene rubber and enough trail feel and agility for technical terrain. And, at the same time, its light weight makes it a solid every day trail trainer ready for just about any terrain.
My test runs included moderately technical rooty and rocky trails, forest paths, rolling gravel roads and some pavement. I found they performed best on the gravel roads.
I tend to agree with Kurt that the heel area needs more solid and stable rear upper hold as lateral stability there does not quite keep up with the rest of the shoe’s capabilities when things get more technical and off camber. More heel counter, higher collars and more collar padding and a deeper seating of the foot into the midsole would improve this part of the shoe as would a bit more front flexibility. That said on less technical terrain the rear of the shoe was fine although I wished for a somewhat more rear rocker to move things along off the landings. And as said above in Upper, I think the toe bumper could be trimmed back off the top of the toes without impacting protection or front hold.
The underfoot experience of Flyspeed Pro and Graphene Grip outsole are the strong points of this smooth riding first big stack longer distances shoe from trail pioneer Inov-8, previously best known for firm, lower stack speedsters. Joining the big shoe race they have done a good job retaining much of that heritage in the TrailFly with more comfort, more cushion, and of course trademark grip.
Sam’s Score: 8.93 /10
Ride (30%): 9
Fit (30%): 8.5 (deductions for rear stability and toe bumper design)
Value (10%): 8.5
Style (5%): 9
Traction (15%): 9.5
Rock protection (10%): 9.5
😊😊😊 1/25 Comparisons
Hoka Mafate Speed (RTR Review)
Kurt: Both shoes play in the same league: long-distance trail crushers with exceptional grip and maximum cushioning.
Hoka uses the dual-density ProFly+ midsole, delivering a soft landing with good energy return. It’s plush, especially under the forefoot, and designed for those who prioritize cushioning over ground contact while the Inov-8 TrailFly Max delivers a natural, foot-shaped fit and better ground feedback. I would recommend the Mafate Speed 4 for more technical terrain and the TrailFly Max for more smoother to moderately technical trails.
Salomon Genesis S/Lab (RTR Review)
Kurt: This is Salomon’s high-performance trail running shoe designed for ultra-distances.
It blends lightweight (260gr US 10) precision with rugged durability (upper made from a lightweight, highly durable, and breathable material reinforced with Kevlar). An Energy Foam midsole offering a responsive and cushioned ride without sacrificing ground feel. Paired with an All Terrain Contagrip outsole and aggressive lugs. An ideal shoe for technical ultras or fast mountain missions. It excels on (wet) rugged terrain, but less in dirt.
If you're racing on technical trails and want a lightweight, agile, race-fit shoe with exceptional foothold go for the Salomon Genesis S/Lab. If you are tackling long distances and prefer a more forgiving, cushioned, and stable platform, the TrailFly Max is your go to.
Sam: No question the Genesis has a superior race fit upper. Underfoot, the Inov-8 is less agile and denser with its foam more reactive and at the same time more protective and less squishy than the Salomon’s EVA blend non supercritical set up.
La Sportiva Prodigo Pro (RTR Review)
Sam: The Prodigio Pro is about the same weight and stack height as the Max. It has a dual supercritical foams midsole (inner core eTPU, outer carrier EVA) and same 4mm lug height outsole.
Its ride is more dynamic from its foams and more pronounced rockers but less stable than the Inov-8 underfoot. The tables turn at the upper level with the Sportiva more supportive at the rear. I am a half size up in the Sportiva at US9 / EU 42 vs. US8.5 /EU 41.5 in the Max.
For slower paces on technical terrain the Inov-8 has the edge while at faster paces on more moderate terrain the Prodigio is a faster choice.
ASICS Trabuco 13 (RTR Review)
Sam: At 10.1oz / 285g US 8.5, so 15 grams heavier, the ASICS has a considerably broader 80mm midfoot platform so is yet more stable. Its heel counter is massive and highly supportive. Its non supercritical foam midsole is similarly dense and about the same softness but is less reactive and duller in ride. Its upper is plusher and roomier. For long days at slower run paces or hiking on rough terrain the Trabuco. For faster paces on moderately technical or non technical terrain clearly the Max. At $140 vs $170 for the Max if speeding along is not a priority the ASICS is a better value.
Hoka Torrent 3 (RTR Review)
Kurt: The Hoka Torrent 3 is a lightweight, versatile trail running shoe that blends agility with protection, making it ideal for runners seeking a responsive ride on varied terrain. The shoe's low-profile cushioning (23mm heel / 18mm forefoot) and 5mm drop provide a natural feel, enhancing ground contact and stability. With 4mm multidirectional lugs, the Torrent 3 delivers reliable traction on diverse surfaces, though it lacks a rock plate, which may affect protection on extremely rugged trails. Overall, the Torrent 3 stands out as a go-to option for shorter and faster trails.
With a 23mm stack height, the Torrent isn’t ideal for longer trail adventures. Instead, it excels on shorter, faster efforts—especially in muddy, technical terrain.
Conclusion: want to go fast opt for Torrent, want go long, opt for TrailFly Max.
Index to all RTR reviews: HERE
The TrailFly Max is available now
INOV-8
Tester Profile
Kurt has a background in long distance triathlon. In recent years his focus is back on running. He recently ran various city marathons like Valencia, Milan and Antwerp. Kurt Is running on Belgian soils meaning mostly flat surfaces. He likes to hit the nearby trails which are mostly gravel and forest surfaces. From autumn to spring his favorite trails are transformed into muddy terrain.
Kurt regularly joins a run or trail race to keep the engine going. But he also likes bigger challenges: he ran Tour du Mont Blanc in 4 days in 2024, ran his first ultra trail (60K), hiked TMB in 9 days with his family and was recently on the starting list of Tenerife Blue trail. He is 1m86cm and 77kg.
Sam is the Editor and Founder of Road Trail Run. He is in his 60’s with 2025 Sam’s 54th year of running roads and trails. He has a decades old 2:28 marathon PR. These days he runs halves in the just sub 1:40 range if he gets very, very lucky. Sam trains 30-40 miles per week mostly at moderate paces on the roads and trails of New Hampshire and Utah be it on the run, hiking or on nordic skis. He is 5’9” tall and weighs about 160 lbs, if he is not enjoying too many fine New England IPA’s.
Samples were provided at no charge for review purposes. RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors'.
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2 comments:
Seems to me that the VJ Ultra 3 would be a natural comparison here.
I have found these to be more protective than the Topo MTN Racer, but with similar fit (in Wide option, though slightly slimmer). The low ankle collars are great for those with sensitive ankles that might be irritated by the harsh collar of the VJ Ultra 3, and the lower ankle collar helps avoid mild irritation becoming day-ending pain on very long efforts. I wish the upper had the materials of the G270v2 though. This mesh is to insulating, and feels sloppy when wet and holds a bit more water than I'd like. The graphene grip is great in slick New England rocks and roots and is perhaps the most durable rubber compound out there.
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