The Inov8 Trailfly Speed. All photos: iRunFar/Bryon Powell
The Inov8 Trailfly Speed ($160) is a no-nonsense trail running shoe. Inov8 succinctly writes on their website that the Trailfly Speeds are “Trail running shoes for fast running on hard trails. Perfect for racing, tempos, fartleks, and speedwork.” I agree with every word. It superbly excels in this realm of trail running as tested across the spectrum of my available speed gears. I would also add that the shoe provides immediate low cushioned comfort for natural gait function — foot expansion and flexion. It feels fast and near minimal, yet balanced with adequate support.
The Trailfly Speed fit is highlighted with exceptional ground feel, sufficient underfoot protection, lightweight upper material, and a wide toebox. Inov8 is really increasing cadence across their models by designing more anatomically shaped running shoes. The designers have a keen sense of natural contours, foot movement, and overall snug fits. It is basic in concept and action, but nuanced in design. The Trailfly Speed only comes in a wide fit, for now, whereas other models may be offered in both a standard/precision and a wide fit.
The Trailfly Speeds are tremendously light in hand and on foot with an actual weight of 9.3 ounces (265 grams) for a U.S. men’s 9. To hone in on the speed aspect of the design — the shoe keeps a low profile with a 22-millimeter heel and 18-millimeter forefoot for a 4-millimeter drop. In my opinion, this is ideal for fast turnover and nimbleness on hard to technical surfaces. The lugs are 4 millimeters, for mild all-terrain capability, and the footbed provides some thick rebound power.
Alas, as stated from the onset and as aptly named — the Trailfly Speed is designed to be light, responsive, and blazing out on the trails. It doesn’t disappoint.
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Inov8 Trailfly Speed Upper
A lateral view of the Inov8 Trailfly Speed.
The Inov8 Trailfly Speed’s upper is light and soft with ample toebox space — more than I would get in some Altras. I truly felt like it was the Topo Terraventure 4’s doppelganger, which is my race shoe, although with some key differences from top to bottom. The Trailfly Speed’s upper is noticeably more minimal and fly-like.
What I really appreciate about the upper is its relaxed feel, breathability, and nearly invisible overlay protection system. It is transparently there, but not overly done or inflexibly fortifying. The upper is created from one piece of material, which I learned is called an air mesh. Overlaying the mesh along the toe and heel are thicker plastic structural pieces — enough for support and protection, but still flexible. Along the medial and lateral sides of the upper, the thermoplastic protection thins mainly for abrasion and upper integrity. Keeping this shoe on the lighter side is fundamental for its swiftness.
The tongue may be the most cushioned part of the shoe. It sits snuggly and is a welcoming pillow under one part of the shoe that seems to come as an afterthought, the laces. As experienced with another Inov8 model, the laces seem below the mark given the totality of the shoe design and purpose. The slender flat design and slight recoil of the material cautions the wearer to retie several times to achieve an exact fit. However, once accomplished, the security is there, and it isn’t something that warrants too much concern. I will also recognize that the laces go through a tongue tab to keep it firmly in place. Perhaps it was the trails and conditions in which I trained, but the tongue and lightly-padded heel effectively fit around my upper foot and lower ankle so that I never worried about debris intrusion. It was a non-issue.
Inov8 Trailfly Speed Midsole
A medial view of the Inov8 Trailfly Speed.
As with most midsoles, the Inov8 Trailfly Speed midsole features a sandwich of materials working together for support, comfort, and rebound. The Trailfly Speed combines its PowerFlow Pro midsole with a Meta-Shank rockplate, topped with a 6mm nitrogen-infused TPU Boomerang insole.
My feet aren’t new to the insole, since Topo models have been using beaded technology for bounce comfort, and water shedding, which I have grown to appreciate and welcome to my running experience. The bounce is just noticeable, but not at the expense of ground feel, since the overall midsole is thin, with a low stack height compared to most trail shoes on the market.
However, my feet never felt vulnerable over a variety of terrain — pavement included. The PowerFlow Pro midsole is also a shock absorber, but super light to help runners hit high speeds. The rockplate takes a less rigid approach, but protects, nonetheless. I realize a midsole like this isn’t for everyone, but in the context of high turnover, hard trails, and hard running, this is a delicious midsole sandwich.
Inov8 Trailfly Speed Outsole
The outsole of the Inov8 Trailfly Speed.
One of the main claims to fame for Inov8 are their Graphene Grip outsoles, as seen on the Inov8 Trailfly Speed. They are superbly grippy and durable. Herein, the outsole doesn’t overwhelm the shoe’s design and purpose. The Trailfly Speeds have 4-millimeter multi-directional lugs, adequate for the hard and fast and most trail environments. They have other models that are undoubtedly more suitable for muddy conditions. After considerable mileage, there remains little wear on the outsole, and I am excited to push them into late fall and winter training.
I have predominantly run on granitic soils over the last several weeks, with some technical volcanic trails in the mix. Where the rubber hits the trail, there has been surety and confidence while running up, down, and across the trails. I also run in VJs, and like the Inov8s, the outsole technology and grip have markedly outshined other shoes claiming extraordinary grip. The grippiest outsoles, however, tend to run poorly on hard and pavement surfaces, but herein, and as experienced with recent VJ models, designers have softened the rubber for more flexibility to allow for a smoother pavement-to-trail transition ride.
Inov8 Trailfly Speed Overall Impressions
A top view of the Inov8 Trailfly Speed.
The last couple of weeks, along with the Inov8 Trailfly Speed, I had several other pairs of shoes to test, while also training for a 100-mile event. The Trailfly Speed joined the arsenal of shoes like a champ and rose to the top for tempo, threshold, and hill workouts. It was reassuring that they ride and feel like the Topo Terraventures while in motion — although a little lighter and closer to the ground. One of the best things about the shoe is the minimal and natural design, promoting foot function and strength. Having them as a staple in my rotation minimized any drastic underfoot stress after any high-volume training weeks.
Post my long endurance events this season, I am eager to test the Trailfly Speed on either a challenging and technical trail marathon or 50k course — just the right distance for this speedster or a shoe. The anatomical fit, wide toebox, and dialed in underfoot design with top-of-the line materials make it ideal to run fast without trepidation and with confidence. The Trailfly Speed — aptly named, aptly inspiring.
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Call for Comments
Have you run in the Inov8 Trailfly Speed? If so, what did you think?
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