Inov8 Trailfly v2 review

The Inov8 Trailfly v2 is an interesting shoe for:

• Runners who need a wide toebox but don't want a zero-drop or low-drop shoe.
• Trail runners seeking a natural ride with good flexibility and moderate cushioning.
• Runners looking for a durable trail shoe that can easily double as a hiking shoe.

Grip is definitely a key aspect of a trail running shoe, and if that's a priority for you, we wouldn't choose the Inov8 Trailfly v2. Instead, check out the Topo Terraventure 5, which also features a wide toebox but pairs it with an excellent Vibram outsole and offers better value overall.

We also don't think runners with narrow feet will find the fit they need in the Trailfly v2. Instead, the HOKA Speedgoat 7 seems like a better deal, and it's also more versatile across different types of terrain.

We found that the Trailfly V2 delivers slightly less shock absorption than average, with 115 SA in the heel and 100 SA in the forefoot. But that was probably expected from this brand anyway.

The Inov8 Trailfly v2 comes with the Powerflow Pro midsole, which undoubtedly has a very flashy name. Its energy return is not as flashy as the name though, scoring 56.1% in the heel and 59.5% in the forefoot.

While this isn't necessarily a negative aspect, it's also far from being an advantage over other trail shoes.

It seems to us that Inov8 is moving the Trailfly v2 toward a feel more in line with most brands, as the heel stack height has increased by 3.9 mm compared to the first-generation Trailfly, reaching 34.0 mm.

For Inov8 fans who prefer a more ground-connected ride, we believe this is far from good news.

We also measured a small increase in forefoot foam, which now reaches 25.3 mm. Again, this feels very much in line with many other trail shoes, although it's still a moderate stack and far from a max-stack design.

The real drop of the Inov8 Trailfly v2 is 8.7 mm according to our lab measurements, and we measured it multiple times to make sure we weren't missing any millimetres.

This makes the shoe highly versatile, accommodating all footstrikes, while being better suited to heel strikers than the 6 mm drop advertised by the brand suggests.

The Powerflow Pro foam in the Trailfly v2 is a tiny bit firmer than our current lab average, but not by much. We measured 39.9 AC using our Asker C durometer, and we believe most runners should find this level of softness comfortable.

We also measured the foam's softness after placing the shoe in the freezer for 20 minutes, which allows us to see how it behaves in cold temperatures. The change was just 11%, which is a solid result and indicates that the foam remains relatively consistent in colder conditions.

While the stack height has increased slightly, we're glad to see that Inov8 has kept the Trailfly v2's midsole geometry very familiar. The forefoot features a very mild curvature that preserves a natural underfoot feel, which also makes it well suited for hiking.

Meanwhile, the heel retains its notable flare and curvature, helping heel strikers transition smoothly into the next step.

Another area that Inov8 fans really value is the anatomical fit, which allows for exceptional toe splay. Let's find out whether that's still the case in version 2.

Our first measurement already exceeds the average by a good margin, reaching 98.8 mm. This is very promising for runners with wide feet or those who simply prefer plenty of real estate in the forefoot.

With the second measurement, the Trailfly v2 further proves that it's an excellent choice for wide feet. We measured 80.0 mm here, which is very similar to what we typically find in wide-foot-friendly brands like Altra and Topo Athletic.

Therefore, runners who value a spacious, anatomical forefoot should feel right at home in the Trailfly v2.

The toebox came in below our current lab average at 26.1 mm, but that's not surprising.

Vertical space doesn't need to be excessive in a trail shoe, and we believe this is a sensible design choice.

The Inov8 Trailfly v2 and its Graphene Grip rubber didn't impress us in our SATRA TM144 traction test. We recorded a score of 0.48, which is clearly below the category average and raises some concerns for runners tackling demanding trails where top-tier grip is essential.

The 3.7 mm lug depth and tight spacing between the lugs clearly point to a shoe built primarily for hard-packed terrain and dry conditions rather than technical, soft, or wet trails.

In our experience, this configuration should perform best on firm, compact surfaces where the closely packed lugs can provide a predictable ride. However, runners tackling loose mud, grass, or particularly slippery terrain may want a more aggressive outsole paired with a better rubber.

The full-length outsole coverage is ideal for durability and protection, although we noticed that Inov8 has added deep flex grooves in multiple directions to keep the shoe highly compliant and allow it to flex naturally with your foot.

The outsole grooves play a major role in how this shoe flexes. Thanks to their design, we found that it scored just 12.3N in our torsional rigidity test, which is lower than the current lab average.

We hoped for a small weight reduction when we reviewed the OG Trailfly in 2024, and we got it.

However, the change is almost unnoticeable, as we tipped the scales at 9.8 oz (278g). That's still a reasonable result for a trail running shoe and, more importantly, good news considering the higher stack height compared to v1.

The Trailfly v2 feels very agile underfoot thanks to its moderate dimensions, but that usually comes with moderate-at-best support.

That's the case here, although we think most neutral runners will find the shoe secure enough. However, runners who need more stability may be better served by a shoe with a wider base and a more rigid structure.

Inov8 has put a lot of effort into making the shoe flexible through its midsole and outsole design, and that clearly pays off. With just 12.8 Nm in our torsional rigidity test, we found that they succeeded in delivering a highly-flexible trail shoe.

The heel counter follows the same design philosophy by avoiding a stiff setup, as we rated it at just 2/5.

It may not provide the strongest hold against lateral forces, but for runners who prefer a shoe that disappears on the foot and stays out of the way, this is a great match.

One of the most noticeable things when wearing the Trailfly v2 is its compact midsole dimensions, something we confirmed with our digital callipers at 111.0 mm in the forefoot. 

This makes it a great choice for runners who dislike tank-like shoes, as well as for everyday use beyond running, such as a quick stroll through a park or along a dirt road.

The heel is also narrower than our current lab average at 83.3 mm, and as the histogram shows, it sits firmly within the first third of the market, making it a particularly compact option for runners who prefer a narrower heel platform.

When we started testing the Trailfly v2 and picked it up for the first time, we immediately noticed that this shoe feels built with durability in mind. And it's not often that a trail shoe gives us such a strong first impression.

Let's see if that impression holds true and whether our initial assessment was right. Starting with the toebox, a perfect 5 out of 5 is an excellent start!

The heel padding also impressed us with its durability, earning a strong 4/5 in our test. In our experience, this level of resistance should hold up well against repeated friction, making the Trailfly v2 a reliable choice for runners who prioritise long-term upper durability.

The outsole wasn't quite as impressive as the upper, although a 0.9 mm result is still a very positive outcome by all accounts.

With an outsole thickness of 1.8 mm, we think the Trailfly v2 provides plenty of protection for demanding trails. On top of that, the shoe features a thin, flexible rock plate that adds another layer of protection without compromising its natural flexibility as we proved before.

The insole of the Inov8 is once again made from TPU-based Boomerang foam, which adds a touch of bounce and improves energy return compared to a basic EVA foam. And as usual, it's extremely thick, measuring a whopping 7.6 mm!

If you dislike such a thick insole or want to create extra toebox height, you can simply swap it for a regular one. That said, you'll lose a bit of breathability if the replacement insole is not perforated like this one.

The Inov8 Trailfly v2 comes without any reflective elements, and when you pair that with this all-black colorway, it's far from the best option for staying visible at night.

Time to gear up with some reflective pants and socks!

The Inov8 Trailfly v2 comes with a classic lacing system featuring punched eyelets and flat laces, with no trail-inspired lace design whatsoever. In this colorway, the all-black treatment extends to the laces for a clean, stain-hiding look.

We found the tongue to be extremely comfortable. At 11.8 mm, it may even feel excessively thick for some runners, although that's ultimately a matter of personal preference. What isn't up for debate is the plush, comfy step-in feel it delivers.

The tongue is semi-gusseted and provides an excellent lockdown, with absolutely no complaints from us.

We also liked the addition of a finger-loop heel tab, which not only makes the shoe easier to put on but also neatly hides the stitching while showcasing the Inov8 branding.

The Inov8 Trailfly v2 sits right on the edge of what we consider reasonable for its modest energy return and grip. Most brands are already using more advanced foams and better outsoles at this price point, but that's not the case with Inov8.

While its durability could make it a solid investment for runners who prioritise longevity, an MSRP closer to £180 than £90 still hurts its overall value.