The Inov8 TrailFly delivers sole-satisfying comfort for miles. It’s not the fastest or the lightest trail shoe, but it offers stability, lots of cushion, and a protective rock plate. With these shoes, you can comfortably cover long distances on rough, rocky terrain.
Inov8 has a reputation for crafting shoes that respect the foot’s natural shape and movement. Their trail running shoe fits solidly within that vision. It offers a moderately wide toe box, low heel drop, and plenty of foot protection.
But the TrailFly truly stands out for its incredibly plush cushion. As the miles accumulated, I noticed the comfort from the sole becoming even more pronounced. It was a plush ride.
Who is it Good For?
- Wide Feet: The wide fit is uniformly sized – good for feet that are a similar width from toe to heel. Consider sizing up if you are between sizes.
- Technical Trails: Protective rock plate and incredible grip even on slick rocks.
- Long Runs: All about the cushion here to keep your legs feeling good for miles.
- Front of the Pack: These won’t be the fleetest shoes in your quiver, but they could be your go-to for long training days and adventure runs.
This trail running shoe is great for runners who love a comfy sole with a wide toebox.
Inov8 TrailFly Overview
The TrailFly immediately impressed me with its low-key color scheme. Here is a colorway designed for muddy trails. The grey would look fresh no matter what I encounter on the trail.
I explored rocky trails, unmaintained throughways, and gravel roads near me in these shoes. Although the heel of the shoe slipped often during my runs, the rest of the shoe performed admirably.
The medley of foams in the sole was impressive. I felt less fatigue in my legs and feet during my long runs.
TrailFly creates the full-squish experience through its beaded insole, comfortable midsole, and protective rock plate. TrailFly’s Boomrang insole is covered in small foam beads. Inov8 claims that these beads compress and return 40% of a runner’s energy with each stride. Tiny perforations in the insole allow air exchange and keep the feet fresh.
The Powerflow Pro midsole provides a stable base without dampening ground feel. This midsole is more cushioned than the TrailFly’s cousin, the TrailFly Speed. While firmer, the TrailFly Speed is lighter and faster.
The final factor in TrailFly’s magic cushioning is the rock plate that protects the forefoot from rocks and roots. It also provides more stability, even on unstable terrain.

The outsole’s rubber has been enhanced with graphene, which is 200x stronger than steel. The Graphene Grip is both sticky and durable. Inov8 claims to have produced the first sport shoe made with graphene in December 2017 and now offer many models with this composite rubber.
The extra tacky outsole felt reliable. I could trust the TrailFly’s tread even on slimy rocks and steep descents.
Inov8 TrailFly Specs
- Weight: 10.7 oz Men’s, 9.9 oz Women’s
- Stack Height: 6 mm
- Heel Drop: 18 mm
- 5 Colors
- Available in wide
- Available on Inov8.com for $92.50-$170
Quick Take
Pros
- Stable rock plate
- Sticky durable outsole
- Comfortable cushion
Cons
- Some heel slipping
- Runs small – size up
- Low rise heel collar
These shoes are not flashy but attractive. I love the muted color scheme. Many colors look lovely out of the box, but they become stained after a few muddy runs. The purple and grey colorway promises to maintain its new-shoe glow even after a few muddy puddles.
Inov8 TrailFly Fit
Inov8 TrailFly has a slight natural foot shape and a springy sole. The shoe runs small, so go up a size if you are between sizes. Also, select the wide fit if you have wide feet or anticipate swelling while running.
I tested the wide fit because my feet have a pronounced forefoot and a narrow heel. While this size was probably the correct one for me, these shoes would be best for a runner with a more consistent or traditional foot shape.
My toes filled the toe box. They were not cramped, as they would be in a traditionally-shaped shoe, and I had no discomfort or chafing while running. But because the toes used all the real estate the toe box provided, I suspect the shoe will show wear on the upper near my toes first.
The TrailFly’s upper is crafted from a flexible and breathable mesh. Overlaying the mesh is a parallel series of strips that tether the upper to the sole. The upper felt secure, cool, and comfortable.
The TrailFly’s thick tongue is attached to the upper. An attached or gusseted tongue prevents dirt and mud from entering the shoe and prevents the tongue from moving out of position. The plentiful padding allows runners to tighten their laces without increasing pressure on the foot.
While the upper and mid were locked-in, the heel slipped as I ran. I suspect the movement originated from two design factors: the shape of the shoe and the height of the heel’s collar.
While offering a wider toe box than many, the TrailFly had a more uniform size than other naturally shaped shoes, such as Topo or Altra. The Wide Fit’s heel was too loose for me, but it may be perfect for other runners.
Secondly, TrailFly’s heel has a low-rise collar. This sat on the wider, lower portion of my heel rather than higher on my narrower ankle. I tried a few different tying techniques to secure the ankle. It was like belting low-rise jeans. The situation improved, but things continued to slide down.
Given the amount of movement at my heel, I expected to develop a blister. But I did not experience any chaffing. This is a testament to the quality of the padded collar, which cushioned and smoothed the movement.
Given how it fit me, I think the TrailFly shape would be ideal for a runner with a uniform foot shape who wants a little more wiggle room in the toe.
Inov8 TrailFly Feel
The Trailfly felt well-cushioned when I laced up. Surprisingly, the cushioning became even more pillowy after running multiple miles.
While running on trails, I noticed the TrailFly’s graphene rubber outsole gripped a variety of terrain in both dry, wet, and snowy conditions. I felt confident navigating granite rocks and muddy paths.
Finally, I appreciate the 6mm drop on the TrailFly. A moderate-to-low heel drop (5-8 mm) is my preferred drop. Lower heel drops may improve running cadence and reduce heel striking, while higher drops may minimize stress on the foot and lower leg.
Inov8’s TrailFly reminds me of Topo’s Mountain Racer. The shoes both come from companies that value a natural foot shape. Both shoes have grippy outsoles, low heel drops, and nubby footbeds.
Both shoes performed well on technical terrain in damp and dry conditions. Mountain Racer uses a Vibram sole, while the TrailFly uses Inov8’s Graphene Grip outsole. The difference between the two outsoles was not obvious to me. Both were reliable in a variety of conditions.
In wet weather, I prefer Topo’s Mountain Racer. The Mountain Racer’s FKT insole provides rapid water drainage as well as rebound.
Topo’s Mountain Racer has a wider toe box and a more natural foot shape. It lacks a rock plate but protects the feet with a higher stack. The Mountain Racer has a 33 mm stack height, compared to TrailFly’s 18 mm stack height.
The Mountain Racer is also lighter than the TrailFly, weighing 8.5 ounces compared to 9.9 ounces. I suspect that much of the weight difference is accounted for by the rock plate. If you prefer a low stack with lots of protection, then the Trailfly is for you.
The TrailFly is a great running shoe if you have a traditionally shaped foot. If you have a wide forefoot and a low-volume foot, the Mountain Racer will be a great alternative. If your foot has a natural shape and high volume, consider the Topo Vista, which has a thinner upper than the Mountain Racer.
There’s much to love with this shoe: the plush insole, the sticky outsole, and the tough upper. I think these would be a great ultra-running shoe for the right foot. Just wish that foot were mine.
Similar Shoes to the Inov8 TrailFly
We’ve tested a few trail running shoes that feel similar, but different based on the brand fit:
- Topo Mountain Racer 4– Both lighter and higher than the TrailFly, the Mountain Racer has a wider toebox and Vibram outsole.
- Hoka Mafate 5 – While not as wide in the toebox, it’s a 5mm drop with cushion and traction that have made a name for this shoe in trail circles
- Altra Lone Peak 9 – One of the most popular wide toebox trail shoes with moderate cushion and a zero drop (for those ok with a little less traction the FWD Via 2 is 4mm and more cushion)
What’s not to love about a trail shoe that has incredible grip, a rock plate for protection and enough cushion to keep the legs feeling great on long days? We found a few personal fit issues, but think this is a sleeper shoe for many!Our Verdict
Who Tried It?
Becky Trudeau lives in New Hampshire and enjoys trail running in the mountains near her home. She has completed multiple half marathons, a mountain marathon, and a 50k with 7,000 feet of elevation. When not running, you may find her mountain biking, backcountry touring, cross-country skiing, or reading a mystery.


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