Shoe Review: HOKA ONE ONE Carbon X

The HOKA ONE ONE Carbon X running shoe

The HOKA ONE ONE Carbon X already broke the world record for 50 miles—and it’s coming for your personal records, too.

HOKA debuted its newest racing shoe in early May during Project Carbon X in Folsom, California. At the event, a group of elite ultramarathoners wore the Carbon X shoe in an attempt to break the 100K world record. No one topped the official 100K mark in the central California heat, but ultrarunner Jim Walmsley broke the 50-mile record with a time of 4:50:09 in the middle of his run.

Now, the shoe is ready topple your best times.

The HOKA Carbon X derives its performance from a minimal, lightweight construction and a curved carbon-fiber plate that gives the shoe an amplified rocker shape and noticeable pop during toe off. In this review, we dive into the technology behind HOKA’s new racing shoe, the fit and how it performed for our testers.

Here’s what you need to know about the new HOKA Carbon X:

Tech specs

  • Price: $180
  • Drop: 5 mm
  • Weight: 7.2 oz, women’s size 7; 8.7 oz, men’s size 9
  • Category: Road racing, neutral
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A used pair of the HOKA ONE ONE Carbon X running shoe

HOKA Carbon X Fit and Materials

From the sole to the upper, HOKA tuned the Carbon X to be an ultra-cushioned, featherweight long-distance running shoe.

On top, HOKA kept things simple: A single layer of engineered mesh wraps around your foot for a streamlined fit.

The mesh doesn’t provide much structure to the midfoot and forefoot—when you take your foot out, it has a tendency to collapse. But the breezy upper keeps the shoe’s weight to a minimum: a men’s size 9 only weighs 8.7 ounces, and a women’s size 7 is 7.2 ounces.

To give the shoe some shape, HOKA embroidered the shoe with stitching that grabs the top eyelet on each side of the shoe and wraps around the heel. There’s no heel counter, but the stitching helps lock down the midfoot and heel. None of our testers felt their heels slip around whether they were logging easy miles, cruising during long runs or hammering 1,000m repeats on well-groomed trail. In fact, one tester set out on a hard (and hot!) long run with a less-than-ideal cinch (she says the shoe didn’t feel tight at all), and she still says her foot felt secure the whole time, and she didn't experience any blistering.

Another one of our runners with high-volume feet says he has to wear the thinnest socks he has to avoid adding extra girth, but none of our testers with average-width feet had any problems.

HOKA punched six lace holes up each side of the shoe for a standard lacing pattern. An empty seventh at the top to lets you customize the fit.

Elite ultrarunners line up for the beginning of the HOKA ONE ONE Carbon X Event

HOKA Carbon X Ride

While the streamlined fit makes the shoe feel like a typical racing shoe, the zippy ride and protective cushion make it stand out.

HOKA coaxed a ridiculously smooth ride out of the shoe by sandwiching a curved carbon-fiber plate between two layers of cushy foam.

The plate adds a couple of noticeable characteristics to the Carbon X:

  • Stiffness. The carbon-fiber plate makes the shoe rigid, which made it more stable on top of HOKA's signature stack of cushioning foam
  • Smoothness. Paired with an exaggerated rocker shape in the midsole and outsole, the plate gives the Carbon X a silky smooth roll from heel to toe

One tester says it gives you the protection of an everyday trainer and the boost of a speed shoe.

“It has a rare combination of the low-to-the-ground feeling and responsiveness of a racing flat and the protectiveness of a high-cushion shoe,” he says.

The HOKA ONE ONE Carbon X uses a carbon-fiber plate to add pop

The protection comes from the Carbon X’s two layers of midsole foam. HOKA used its PROFLY X foam above the carbon-fiber plate to give it a soft landing and a rubberized foam beneath the plate for a better response.

All that foam provides ample protection against hard pavement and debris. It doesn’t have the same squishy feeling as other HOKA running shoes, like the Bondi 6 or Clifton 6, but it’s not supposed to.

“The Carbon X is lightweight and fast on the flats and uphill, and super-high cushion on the downhill, especially in the heel,” one tester says. “I was running fast on irregular trail surfaces from gravel to grass to dirt and felt stable and efficient.”

Our testers love the Carbon X’s inherent stability. HOKA built the shoe with a wide footbed and flared midsole that provide a stable platform to land on and push off from. Thanks to the width, the shoe feels confident in any situation.

There’s no outsole rubber to give it extra grip (or any extra weight), but none of our testers noticed any problems with their footing on dry pavement or hard-packed trails.

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The Carbon X is a dazzling debut for HOKA.

It’s a speedy, lightweight racing shoe that feels cushioned enough to be an everyday trainer. We love its minimal upper, clean design and straightforward laces.

But the Carbon X really shines on the road. The shoe feels quick and smooth, and it gets a significant boost from the carbon-fiber plate that propels you forward with each step.

Still not convinced? Don’t sweat it. Fleet Feet's return policy means you can test drive your shoes and gear without risk. If you’re not happy with the way your gear performs, looks or fits, we’ll take it back within 60 days. Plus, you’ll get free return shipping on all orders. That's our Happy Fit Guarantee.

By Evan Matsumoto. Evan played many sports growing up but didn’t go pro in any of them. Now, he’s the digital copywriter for and editor for the Fleet Feet blog where he writes about different foam densities and engineered mesh uppers.

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