HOKA Carbon X
photo: Adam Chase

HOKA ONE ONE Carbon X Review: 100 Mile Rundown

HOKA's Carbon X is the “Chutzpah Shoe” of ultradistance road running: Aggressive and punchy, an audacious companion for long, stable, cushioned yet efficient efforts.

HOKA Carbon X

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The Rundown

Stack Height:

When a friend asked my thoughts about the HOKA Carbon X, he referred to them as the “Chutzpah Shoes.” After putting 100 miles on them, I decided that was an accurate moniker. The impudent, trampoline-like meta rocker shoes roll and spring with a sort of squish-pop action that propels the foot’s natural roll-through in a fluid, stable manner. The cushioning and flow provide a snappy confidence to help pick up the pace and get you quickly to your toes.

While a bit much for shorter races, the Carbon X is well suited for a marathon, an ultra—such as Jim Walmsley’s 50-mile world record set at the shoe’s impressive launch—or the hilly 55 miles of Comrades in South Africa, where HOKA athlete Sage Canaday will soon be giving them a go.

photo: Adam Chase

The Specs

7.2 oz. (W), 8.5 oz. (M)
5 mm
30 mm/25 mm (W), 32 mm/27 mm (M)
A softer foam (new PROFLY X) sits on top a 1.5mm carbon plate that rests over injected rubberized EVA.
Injected rubberized EVA (lower midsole layer)
Single-layered engineered mesh with cored mesh tongue

100 Miles In: The Review

The challenge in testing the Carbon X for 100 miles was that, because they function, feel and perform better at a faster clip, they demanded that I pick up the pace. This was a good thing, though, as the reward was better training.

The Carbon X is a racing shoe, and as such, isn’t designed to withstand much more than 300 miles. The exposed midsole, lacking any outsole rubber, showed wear even after 100 miles.

HOKA Carbon X sole
photo: Adam Chase

That said, the Carbon X defies common racer notions with its comfort and cushioning. The shoe a not a “flat,” given its amplified rocker design and stability platform that helps move the foot to toe-off effectively, regardless whether you land fore-, mid- or rear-foot. The carbon plate follows the foot’s natural curve and transitions fluidly with the gait cycle, providing a welcome springiness, especially at a sub-7-minute-mile pace and on descents.

The HOKA marshmallowy dual-midsole materials provided a novel impression of loading and releasing, with the carbon exaggerating that sensation in a welcome manner. It was hard to tell exactly why the Carbon X came together so well at a quicker pace, but it may be that a higher cadence translates to less contact time so there was a quicker transition and less depression into the midsole layers.

Runners who have had trouble with HOKA’s forefoot fit will welcome the wider forefoot platform and more accommodating toe box than we’re used to seeing from the brand.

With no outsole, the Carbon X is certainly not intended for off-road running, but the carbon plate served well for underfoot protection on the few trails of the testing. HOKA has said the brand is exploring “other applications” of the carbon plate and it will be interesting to see how that eventually makes its way to market.

photo: Adam Chase

There’s The Rub

The Carbon X is rather difficult to get your foot into because of the floppiness of the fabric heel that lacks enough rigid structure to serve as a shoe horn. While this would be a big minus to triathletes transitioning after the cycling leg, it isn’t a deal breaker for runners because the heel fit and hold are fine in action.

Once on, the shoe felt rather snug and secure, except the lacing, which tends to want to come undone, even when double tied. The weight is fine for ultrarunners, marathoners or even half marathoners who want cushioning and performance but the shoe runs too heavy for shorter distances.


The Carbon X is essentially HOKA’s ultra version of Nike’s 4% Vapor Fly. Note, however, that HOKA has been exploring the max-cushioned, rockered space since the company’s inception and brings their own take and expertise to the concept. What Nike brought to the marathon, HOKA now brings to longer road racing in terms of efficiency and functionality: Call it chutzpah.

The carbon plate sandwiched between layers of soft upper foam and harder lower EVA provides a unique midsole that cushions and propels, especially at faster paces. At $180 for what will be 200–400 miles of racing, the Carbon X is fairly priced, given design and expensive materials that went into the shoe and knowing that it will help you power through several ultras or marathons with comfort and speed.

From PodiumRunner