Robbe: The way things are going, the EPA will have to start regulating shoes if the carbon trend keeps up. Following Nike’s resounding success of the Vaporfly 4%, HOKA has responded with the Carbon X, a lightweight but well-cushioned shoe with a carbon fiber plate that acts as a propulsion source for that extra boost during tempo and race scenarios. The carbon fiber plate in the midsole is sandwiched by CM Betty Fly foam on the top and EVA foam underneath.
The shoe also features an amplified rocker design and a light and airy mesh upper, with a lightweight Lycra tongue gusset and a cored mesh tongue for superior breathability. At 8.7 oz. for a size 9 it’s not the lightest shoe in the carbon plate space, but its extra weight is offset by its speed technologies.
Straight up, there’s a lot going on with this shoe, some good, some bad, some just different.
Coach Dave: One of the greatest movies ever was The Hunt for Red October. If I owned a Hollywood studio, I could make a movie out of my hunt for a HOKA road shoe, red or otherwise. I’ve never found one I’ve liked, and I’ve run in them all. Including the new Carbon Rocket, which, unfortunately, shredded my foot (the plate was far too firm).
Nevertheless—publicity events and Jim Walmsley records aside—I was excited to at least give the Carbon X a try. No doubt it was marketed well, and in this shoe review game, you’ve got to give everything a chance.
(Side note: while I’m not a HOKA road fan, I really enjoy their trail shoes, including the EVO Mafate, Torrent, and Challenger ATR5. All well within my wheelhouse for endurance running in the dirt. All firm and not a biomechanical marshmallowy nightmare.)Shop HOKA Carbon X
Coach Dave: When I try a shoe, my first impression is based on the slip-on feel, not looks. To me, that’s where the initial excitement or disappointment begins. The Carbon X goes on so smooth. Looks-wise, I’ll admit I was originally a bit skeptical by the loosely designed upper, but it molded my narrow foot well. The lacing was premier and the mold on my foot was locked and loaded. If it’s going to be a rocket ship, it’s gotta mold your foot!
This shoe can roll, plain and simple. My first sesh in it was a 10-mile progression run closing the last 4 miles in 6:00, 5:50, 5:40, 5:35. For this washed up, pushing-40 coach, I was damn hyped about it! The carbon fiber plate is not giving you the overly firm feeling underfoot like the Carbon Rocket did. It’s mellowed out. It’s smoother and works with the foot better. It’s gently explosive if I had to make up a term. Combine that with Pro Fly layered on top of the plate and yeah, this shoe can get righteous.
If you are looking for the soft squishy HOKA with no speed or quick transition rate (like most of their road shoe), look elsewhere.
It’s firmer, so you need to like shoes that have snap. But it rides that balance between firmness and comfort. This is the perfect shoe for half marathon or marathon-paced segments of long runs, steadier long runs, road ultra, Fartleks, and progression runs. It will struggle at interval pace or repetition pace due to high stacks. I’ll get into that in a bit. Running feels effortless in this shoe, which I guess is the overall goal, right? Easy cruiser days flow, too.
Robbe: I’m going to reiterate some of the same things that Dave has covered. The upper is exceptionally light and breathable, and it does have a good lockdown. I initially had the same thoughts as he on the “extra fabric” but it turned out to be fine, with just the right amount of room in the toe box. It’s a great summer shoe. The cushion is there, in pretty much just the right amount to give it long-lasting comfort.
Speedwise, the carbon plate pops. The times I did push the pace I definitely felt the pickup and I was plenty okay with it. As you’ll see below, most of my running was during very slow, long run paces, so you should defer to Dave when looking for the best opinion on speedier runs.
Nevertheless, this is undeniably a fast shoe with more-than-adequate cushioning.
Meaghan: My first step into this shoe had me excited. The rocker is overtly obvious, I’m talking tiny-rocking-chair-under-your-foot rocker, that propels you forward. It’s apparent the second you slip them on. I know all the chatter is about the carbon plate and if it’s a Vaporfly 4% equivalent (spoiler alert: it’s not) but that meta-rocker geometry? I’m here for it.
True to HOKA, the Carbon X is a maximally cushioned shoe. The carbon plate is sandwiched between two slabs of foam, the top layer for comfort and the bottom layer for performance. Even with the super stiff carbon plate, these shoes felt comfortable out on the road. I tend to land on my heel and the plate had me rolling right through to toe-off.
The fit is perfect. These shoes accommodate my wide feet and the minimally-designed upper provides everything you need and nothing you don’t. It’s breathable, light and locks down the foot.Shop HOKA Carbon X
Coach Dave: Remember a few years ago when there was a break-in period during the failed barefoot running phase (i.e. you had to slowly work into a New Balance Minimus to transition)? Well, there’s a break in period for maximalism.
I guess I just can’t handle it. I just don’t run maximal enough (not a big biomechanical believer in it). While this shoe is absolutely amazing, I pay the price for running in it. Just like the recent Rincon, I was banged up bad in my hammies and glutes. While the X definitely keeps me fresher during a run compared to other HOKA road shoes, I pay the consequences after. I’m 65 miles into the shoe and I leave every run a bit sorer and inflamed.
The only other negative is that the shoe cannot transition well at faster speeds. I find this shoe will struggle at 5K or on the track for a Vo2 session. It’s dialed in for longer distance workouts and races. Just like Nike has shaved off stack height on the upcoming NEXT%, HOKA could make this an even more versatile weapon by doing the same. Make it feel the roads a bit more. My legs would appreciate it.
Robbe: Okay, so I admittedly have not run in many rocker-style combined with carbon plate and light mesh upper shoes. This is certainly the first shoe I’ve run in with all of those technologies combined. The result was… confusing.
I wore those for over 30 miles, over the course of several runs in the 8-14 mile range. I’m training for a trail race, while also doing heart-rate training, so I was moving slow. These are not meant for moving slow. My shortened stride kept me at the front of these (at least I feel that’s what was going on), where the plate is kind of cantilevered for that propulsion. I wasn’t really experiencing that roll-through that the shoe intended, and as a result, my calves were doing a lot of work and felt pretty beat up. Like I said though, this isn’t really a knock on the shoe since I wasn’t using it in its intended way.
The upper provides little support, and as with other HOKA models, I just can’t get a good feel for the road. As a result, I felt unsteady taking turns and actually rolled or almost-rolled my ankles on a few occasions.
The other thing is that the carbon plate is shaped in such a way that it’s “designed to split and curl under the lateral toes which allow for resupination,” which just felt weird to me, like I was being forced into a gait I didn’t want. Maybe this is a good thing in the long run, but I couldn’t get used to it.
Meaghan: I don’t have many negative things to say about the shoe. I don’t think it’s a Vaporfly 4% replacement, but these shoes fell into my lap as I was heading into taper. I did use them for my final long run with MP segments and I was not feeling fresh. I’m not blaming the shoes, but I’m also not seeing the magic.Shop HOKA Carbon X
HOKA ONE ONE Carbon X Conclusion
Meaghan: I’m a fan of HOKA and I’m a fan of the Carbon X. In fact, as I am writing this review I realize I’ve already put over 40 miles on them, just in the past couple of weeks. I don’t see the Carbon X as my race day shoe, but I will wear them for easy runs, all day long.
Coach Dave: Overall, this is a great shoe—if you can handle it. Also, a big shout out to HOKA for coming correct in a Nike-dominated industry right now in terms of design and innovation. It’s $180 bones. Yes, less than the Vaporfly, but still an investment.
It’s fast, so fast. But leaves me cautious to use it more often because of its post-run effects. I have no issues with other speed shoes (i.e. Skechers Performance Razor 3, Adios 4, Reebok Run Fast, even Fast Pro). For the doubters out there: I’m training smarter than I ever have in my life. It’s not my running.
So that leaves me with a dilemma. I’d rather run healthy than obsess about why I can’t wear a shoe.
Only changes would be to reduce the stacks and level this baby off a bit. Make it even more of a weapon! It may allow a lot more people to run in it. If you are a HOKA head, or can handle the maximalism movement, you are going to rock this. If you’re on the fence or don’t have the legs for maximalism, stick with what works. It won’t be worth the investment for it to sit in the rack.
Robbe: I like what HOKA is doing here. They’re showing they can play with the big boys, but within their own lane. It’s important to note that at their core, these are a HOKA. That said, by trimming some of the typical HOKA-ness away and trading it in for speed, they’ve opened themselves to a different type of runner—the fast road runner.
I don’t think the shoe is perfect (I’d love a rocker-less version), but if you’re into the rocker-with-carbon style, I think you’ll find this shoe will kick some serious ass for you. And even at $180, it’s still 30% cheaper than the ASICS and Nike style iterations. Get yours at Running Warehouse using the shop link below.Shop HOKA Carbon X
Robbe is the Senior Editor/Review Manager for BITR. He lives in Baltimore with his wife and two sons and runs with the Faster Bastards when he’s not MAF training. His favorite race distance is the marathon and his favorite beer is anything but Blue Moon.