Wednesday, May 01, 2019

Hoka ONE ONE Carbon X Review: Maximal Cushion with Carbon Propulsion

Article by Sam Winebaum

Update: Read our nine tester full in depth review of Carbon X HERE

Hoka ONE ONE Carbon X ($180)
Initial release color. I tested an all white prototype
The Hoka Carbon X will be “introduced” on May 4th at a special race in California. Several Hoka elite athletes will be chasing world road 100K records in the X. 

Update: Jim Walmsley breaks the world 50 mile record in the Carbon X with a 4:50:08, 43 seconds better than the prior 1984 record by Bruce Fordyce, 

And the Carbon X was a totally appropriate running shoe for the quest.  It is a light 8.5 oz / 241 g, maximally cushioned (32mm heel / 27 mm heel) long racer and trainer with a propulsive carbon fiber plate. I have extensively tested the X, running over 70 miles and two long races in them.

“The Carbon X embodies everything that has made HOKA such a popular and quickly-growing brand,” said Gretchen Weimer, Vice President of Product at HOKA ONE ONE. “Combining premium performance engineering, an extraordinary weight-to-cushion ratio, and a user-friendly geometry and ride, this shoe is designed to empower athletes the world over, and to help them feel like they can fly.” ​
The  carbon fiber plate is embedded above the thick rubberized foam outsole (the first line up from the bottom in the picture above where the blue midsole starts). In addition to the carbon plate, it features an aggressive Metarocker and Hoka’s active foot frame construction which embeds the foot in the midsole.

The Carbon X will be available at May 15th with other select retailers coming June 1st. My pair was an all white pre production prototype. The first release color, the same for both women’s and men’s sizing, is below with more colors to drop in July and August 2019.

Many will immediately seek to compare it to the Nike Vapor Fly.  While they share carbon plates and lots of cushion for a racing shoe, they are very different beasts. Whereas the Vapor Fly can be thought of racing shoe that can be trained in, the Carbon X for most of us will be a training shoe that can be raced. Incredibly well cushioned, in a softer and slightly bouncy way with in the mix the carbon fiber plate pop, it is very broad and stable on the ground. It has a very thin and comfortable overlay free upper. Its  thick rubberized foam outsole has proved exceptionally durable with over 75 miles on the counter to date.
Its stiff carbon chassis provides stability, an easy going rocker powered ride and a fairly gentle non harsh propulsive feel at all paces, except maybe very fast paces for me given the high stack of soft foam and the rubberized foam outsole. 
 I have been testing a Carbon X prototype, top to bottom all white, for more than a month. Nobody, literally nobody, has noticed them or asked a single question about them. Cool camouflage!

I have run more than 70 miles in my prototype, including a 20 mile Boston tune up race, easily done at 8:04/mile pace with minimal soreness the next day. and none during, and the marathon itself, a disaster for me due to allergies and in no way due to the shoe.  

Several of us at RoadTrailRun will be testing for our multi-tester but here is my take.

  • The most runnable and comfortable maximally cushioned road shoe I have tested to date.
  • Ultimate, long run, heavy mileage softer shoe, and for many (including me) an ideal most paces daily trainer. All paces from very slow to tempo are easily and smoothly accommodated in a bouncy soft yet smooth and steady steady way.
  • In no way a mushy chore to run despite the supreme cushion.
  • Very stable platform for such a big stack height, or for any shoe for that matter 
  • Very comfortable, breathable, super light and roomy upper with surprising hold, if it fits.
  • Noticeable carbon plate pop and stability, especially at the forefoot, although muted by the cushion above and below 
  • Very durable outsole; very minimal wear from the rubberized foam outsole at 70 plus miles.
  • Very ow volume and narrow feet may be challenged by the fit, especially at midfoot and heel.
  • Heel hold down low could be improved via a more effective sockliner, hopefully to come with production.  
  • Not as dynamic and responsive as I would like at faster than marathon to half pace racing, but then again Hoka has the Carbon Rocket for that.
  • There is a lot of substance in cushion stack and platform width but weight is up there for the racing game due to the use of an EVA foam and not an exotic super foam, albeit a light lively flavor of EVA

Official Weight: 8.5 oz /  241 g
US M9 Proto Sample: 246 g / 8.68 oz (glued in removable thin contoured sockliner)
                         252 g / 8.89 oz (supplied thicker sockliner with glued in removed)
Stack Height: 32 mm heel / 27 mm foretoot, 5mm
$180. Available May 15 at June 1 at other select retailers.
Watch our YouTube Review 

First Impressions and Fit
The initial fit with the prototype glued in thin sockliner was a challenge at half size up from my normal.  Hoka sent along a more conventional, albeit still thin pre production sockliner. Removing the glued in sockliner and substituting allowed me to run and race with Salomon Long Run socks (medium thickness) with their silicone foot strips with no issues, zero blisters, irritation or pressure, ever. The production sock liner will be different and lightly glued in. I will be receiving a true to size pair with production liner. 

The upper is very thin, pliable and soft with no overlays. It is similar in texture to the Reebok Floatride Run Fast but a bit more pliable. It is completely unlined whereas the Reebok has a thin liner.

Those expecting a locked down race shoe fit will not find it here. Soft, roomy, but well enough held, this is an upper designed for long distances on the road in hot and/or wet conditions. The fit was comparable to the very first original baby blue Vapor Fly albeit here we have a thinner more pliable (and breathable) upper. Narrow, very low volume feet may be challenged but with a thicker sockliner or socks or potentially sizing down a half most should be OK. Note there is also no toe bumper or stiffener whatsoever upfront beyond a very pliable underlay

I won’t comment on the all white look expect to say that no one even noticed or asked me about the shoe in my “secret” testing and racing. The production launch colors will make the stack look less massive with the blue and white contrasting layers.

The upper is a very light, dense weave, very pliable, single layer, non stretch engineered mesh.
Similar in materials, the mesh is thinner and considerably more pliable than the original Vapor Fly’s upper and clearly less dense and three dimensional than Nike’s Flyknit in the more recent Vapor Fly. The mesh is most similar to the Reebok Floatride Run Fast and Pro uppers although, unlike the Fast’s, it is unlined. It is an incredibly comfortable upper on the foot and I think perfectly suited to its ultra road mission.
The thinly padded tongue has a raised grid pattern below a non slip outer material with a thin soft, stretchy mesh backing on the foot.
There is a very thin, highly breathable stretch bootie connecting tongue to midsole. The tongue, lacing, and upper work quite well, despite their seeming lack of any structure to hold the foot to the broad mid foot platform with the rear active foot frame midsole sidewalls certainly assisting.
The heel and achilles collars is lightly and softly padded. 

In this area we see the only “overlays”, actually stitched in threads connecting lace up to the heel.
The toe box has has a very thin very pliable underlay at the toe bumper but otherwise is completely overlay or even inner mesh lining free. The front foothold is excellent and totally pressure free if roomy.
This is one highly breathable, drainable, non water absorbing upper. I dumped lots of water on my head at Boston and never had that squishy shoe feel or any sense of a gain in shoe weight. Note the light coming through the unlined upper and even the stretch bootie in the photo above.
There is a very minimal heel counter but there is one. It is vertical at the rear ,about an inch wide, and stiff for the first inch or so then has a softer stiffener above.
The rear clearly uses Hoka’s active foot frame for hold and stability as the midsole rises around the rear with the foot sitting down in the shoe.

I played with various sock liners to improve the bottom of the rear heel hold at the sides just ahead of that vertical narrow heel counter. It seems there is a bit to much room width wise there for me and a sock liner with a more pronounced cup worked best. I hope the production liner is such a liner.

Midsole and Outsole

The midsole is light compression molded EVA with 66% of the stack above the carbon plate. The carbon fiber plate is located just above the first line (change in midsole color to blue) up from the outsole in the photo above and seem to sits approximately 15mm above the ground at the heel and is at 10mm towards the front.  It curves up under the lateral toes to prevent re-supination

The plate location is lower at the heel and higher at forefoot than in the Vapor Fly where the plate curves down from heel to forefoot in a spoon shape. On the run, the X carbon fiber plate location results in both a softer heel and forefoot feel for the Carbon X and a somewhat flatter lower drop feeling ride when the 5mm drop vs. 10 mm for Vapor Fly is also taken into account.

Hoka describes the PROFLY X cushioning and propulsion system (midsole and foam outsole) as:
Carbon X uses more resilient foams  (than other Hoka’s such as Clifton). It has  a strong compression set. This makes the feel very responsive and supportive, and should hold its shape better in the long term. Higher specific gravity means that it is not the lightest weight Hoka foam, and as a result it also doesn’t feel as soft/mushy. Rubberized foam (highly resilient) is used as the outsole with the carbon fiber plate changing how impact causes the foam layers to interact.
The full length carbon plate is located just above the thick rubberized foam outsole and is seen through the cavity just ahead of the heel. Mid and forefoot strikers should be very pleased with the geometry as should moderate overpronators. Heel strikers, such as I am,need to focus on landing further forward with a slightly more pronounced forward lean or drive to keep off the heel.
The outsole is an injected rubberized foam.
I varies in thickness which I measure as approximately 15mm at the heel thinning to about10mm up front just behind the final toe off outsole which is somewhat thinner yet.
The wear of the outsole has been remarkable. It is barely scuffed in high wear places, with no visible loss of thickness beyond the dot pattern after 70 miles of fast pace running.
Note that the center areas above had no outsole pattern. I do wonder if the completely unworn rear bevel area is overly long and adds to weight and if its mass far to the rear contributes to slowing transition off the heel.

Grip is excellent in large part due to massive on the ground full contact.
The platform is wide and stable front to back.
Heel landings say on steep downhills are remarkably well cushioned yet stable with no bottoming out.
The contrast with the Vapor Fly’s heel is striking and while I am fine on smoother level roads in them, on steep downhills or uneven pavement the Vapor Fly is nowhere near as stable.
And seen from the bottom one can clearly see a wider heel landing, more filled in mid foot and somewhat narrower forefoot in the X. The pluses of the Carbon X geometry are considerably better stability and support but more weight and a somewhat less dynamic overall ride and toe off propulsive sensation.

First, no one will ever complain the Carbon X doesn’t have enough cushion for heavy mileage at pretty much any training pace. There is tons of well controlled softer cushion here with a fantastic mellow sinking, bounce and some spring. I say bounce and spring as the foot clearly sinks into the soft foam, meeting first the stiff plate and then the rubberized foam to provide a pleasant feeling with a muted (by the stack above and thick outsole)  yet quite decisive energy “return”.

The 5mm drop is not flat feeling (as in the 1mm carbon plated Carbon Rocket) or with a pronounced sense of heel height then plunging to the toe (Vapor Fly). I did feel that the midsole/outsole foam softness in such a thick stack, or maybe the weight and width of the rear beveled area, or possibly the near the ground location of the plate, or the wide midfoot platform geometry or some combination had me lingering on the heel longer than I would like in a half marathon type racing shoe. More midfoot to forefoot strikers will likely not notice this. This said, the ride was sublime for all forms long run training, soft enough, energetic, stable with a super well cushioned yet dynamic.

The forefoot is soft and incredibly plushly cushioned but also stable with muted snap from the full carbon plate. While I never had  tired or sore feet on any run, I found the forefoot a bit soft and plush for my tastes as when the pace picked up to my half pace of around 7:30-7:40/ mile pace things were not as snappy as I would like with the feeling  of a more soft very stable bounce than quick response.

One can sense the snap provided by the plate but due to the cushioning above and below there is never also a sense of abruptness or firmness in its interaction with the rest of midsole and outsole.

There is also not as pronounced a forward sinking sensation as in the Vapor Fly where one sinks all the way down to its plate and then to a sharp toe off. There is clearly a more cushioned forefoot feel here when compared to the current Vapor Fly, with testing of the %Next with additional forefoot foam to come. There is a sense of a forward compression of the midsole then spring from the plate and rebound from the rubberized foam outsole. 

Despite the stiffness of the shoe, there is not the usual Hoka need to use a very pronounced knee drive to move off the rocker.  This said the ideal paces for the shoe for me were tempo to marathon pace, as while stable and dynamic at those paces the softness starts to catch up with the need to toe off fast and decisively as the pace quickens.

Conclusions & Recommendations
The Carbon X was created for elite Ultra road racing. It provides a unique blend of soft, bouncy, very plentiful cushion, stability and carbon powered propulsion. It has proven a very fine longer than half racer for me but its real strength for me is as a heavy mileage, anything but the fastest tempo paces, light weight trainer. Recovery runs, daily mileage, long runs at most all paces are gobbled up with ease by the X. The soft high heel stack and 5mm drop tend to start to have me lingering at the heel at faster paces and the forefoot could be a touch firmer. I do wish for a touch more drop overall or slightly firmer midsole foam.
Carbon X has a very comfortable, minimal, pliable, thin, single layer upper. It does not have the usual race snug shoe upper. It is airy and roomy yet is decently supportive. This upper is ideal for summer heat and long run foot swelling as well as wet conditions as I found almost no water is absorbed and drainage is excellent. Never any blisters, arch bite, pressure or irritation of any kind beyond a touch of lace bite using thinner socks in my half size up from normal pair.
The fit is quite voluminous. High volume feet should be very happy in this upper. Note the height and room when stuffed with paper in the photo above. Not to worry the upper wraps the foot very well if you don’t have a low low volume foot, but again with a more "comfort "as opposed to snug performance fit. Very low volume feet may struggle to fit and may need to consider sizing down a half size or using slightly thicker socks.  There are no overlays and stiffening way up front to get in the way of toes. Overall at a half size up, I found the fit appropriate for the long, long run purpose of the shoe but would be happier at true to size.

The smile and comfort factor is huge with this shoe. It is one of the finest, most fun and most comfortable, top to bottom. trainers of recent years, if not ever, for me. Very decently light for their maximal stack at around 8.5 oz , soft and easy running, they shine at slow to tempo paces for me so as intended ultra paces. The outsole durability has been outstanding to date indicating a long long run life in the X. And, as they firm up over time I suspect their shorter racing performance will improve. If you are seeking the ultimate in light weight super cushion and comfort, with the snap and stabilizing influence of carbon in the mix, the Carbon X is a great new option.
Sam’s Score 9.80/10
My deductions are for “shorter” racing distance performance and fast pace use. As a do anything trainer they would yet closer to a 10. I deduct for heel and forefoot softness and muted or delayed responsiveness at marathon to half and faster paces, they are just a bit to forgiving, and for weight. A bit less stack overall, a closer to the foot carbon plate at the heel, more drop, or a slightly firmer or non EVA more energy returning foam in the mix (but not as firm as Carbon Rocket’s) or a combination would move the X into Vapor Fly racing territory.

Vapor Fly 4%
Original July 2017 Blue (RTR Review)
The very first 2017 Vapor Fly was softer and bouncier than subsequent versions such as the Obsidian color for me and is  closest in cushion feel to the Carbon X. Its roomy, if somewhat thicker upper, is similar in fit to the Carbon X with slightly better heel hold. The Vapor Fly’s narrower midfoot platform and broad upper made it feel like the foot was collapsing to toe off and that was a great feature to drive down and forward to take advantage of the plate.  I do miss the 10mm drop of the VF in the Carbon X at faster paces, where along with the plate closer to the heel the drop helped drive the foot forward and down to toe off. The OG VF was truly outstanding for racing marathons all the way down to 5K for me, but I would pick the Carbon X for a hilly course such as Boston due to its stability on the hills or rough pavement and for later marathon race miles if you tend to end up back on the heels when tired.. This said, while some train in Vapor Fly they don’t hold a candle to the Carbon X when slower paces, for me 8:30 to 9:20 minute miles and slower are in the training mix as their heel landing is narrow and unstable in comparison. While not the ultimate racer as the VF has proven to be for many, the Carbon X is for me the ultimate, super cushioned performance trainer.

Flyknit (RTR Review)
The Flyknit upper is effective but has a far more performance oriented snug fit than Carbon X. Not a shoe I would train in, or be happy in with swelling feet in summer heat as I would be in the Carbon X. Considerably firmer than the original Vapor Fly the newer Vapor Fly, while still magical, it is far less comfortable or easy to push fast than the original.  

Nike Vapor Fly %Next  
I haven’t yet tried the %Next but suspect with its increased forefoot cushion stack and 2mm lower drop at 8mm it will feel  closer to Carbon X than prior Vapor Fly upfront. It’s Vaporweave upper echoes the thin upper of the Carbon X but it is unclear to me as of yet how pliable it is. Clearly it weighs considerably less and it also seems likely it will be less stable at the rear than Carbon X.

Hoka One One Carbon Rocket (RTR Review)
The Carbon Rocket is Hoka’s elite road racing and marathon shoe with carbon fiber plate above a rubberized outsole so a very similar construction. It  feels considerably firmer than Carbon X, yet I find it also incredibly well cushioned and easy on the legs. It weighs almost an ounce and a half less than the  X. It is on narrower platform with a firmer dual density midsole with an overall lower stack which is 26mm at the heel, 25mm at the forefoot, so 6 mm lower at the heel and 1mm lower up front. I has a somewhat thinner 8mm rubberized foam outsole with some rubber patches. Rocket has a 1mm drop vs. the 5mm of the X.  I found the Carbon X heel height feel to be only slightly higher than the Rocket’s, likely due to the Rocket’s firmer midsole and patches of heel rubber. Some of our testers found it “flat” feeling and firm. I personally did find it different but a very fast and very easy on the legs shoe and ran distances up to 15 miles in them. Its very thin upper is clearly a more speed performance oriented fit while in no way being uncomfortable. I prefer Rocket’s upper for racing and just barely X’s for training It comes down to preferences. If you like a softer bouncy more training focused ride the Carbon X, if you prefer a firmer highly responsive Carbon Rocket

Hoka One One Rincon (RTR review)
The Rincon is considerably lighter at 7.1 oz. It is somewhat firmer and not as springy as it has no carbon fiber plate. It actually flexes, a first for me in a Hoka whereas X is entirely stiff and rocker based. If you like a very well cushioned ride in a shorter race capable shoeor  for faster training paces in a Hoka Rincon makes a good pairing with X, with X the big mileage and slower days shoe.

Skechers Performance Ultra Road 3 and Max Road 4 Hyper (review soon)
Both Skechers Ultra shoes share a similar maximally cushioned softer ride with the Carbon X. I have wear tested the Max Road Hyper and it is the shoe I might put closest to the Carbon X. While it does not have a carbon fiber plate for that distinctive dynamic pop off the forefoot or quite the downhill and overall stability of the X, its Hyper Burst foam midsole is plenty stable, very well cushioned with a more springy lively feel inherent to the foam itself with the midsole a single layer with a more conventional outsole.

Pegasus Turbo (RTR Review)
Also soft with similar heel cushioning feel the Turbo is not nearly as stable front to back and has a soft kind of formlesst feel. Its awkward upper is not nearly as comfortable, especially upfront. Despite Zoom X foam which has more rebound feel in the Turbo the return is poorly “managed”, Carbon X all day any day for me in the soft faster trainer category.

New Balance Fresh Foam More (RTR Review)
The More is maximally cushioned but considerably firmer in feel. Also a very stiff shoe its geometry seems to lack an effective rocker in comparison to Carbon X. I would call it more responsive in feel but not nearly as much fun to run daily as the Carbon X. Its upper can be challenging for lower volume feet, more so than the Carbon X’s for me as it less pliable.

Update: Read our 9 tester in depth review CLICK HERE

Reviewer Bio
Sam Winebaum, Road Trail Run Editor and Founder
Sam is a 1:38 half marathoner on a good day and didn't mind at all going into his 60+ age group in 2017. He has been running for 45 years and has a very dated marathon PR of 2:28. Update: maybe he can still run fast as he clocked at 1:35 recently and last year a 3:40 Boston Marathon qualifier, surprising him.  He runs 40 miles per week along the New Hampshire Seacoast and on Park City, UT trails, clocking test runs in well over 80 different shoes per year.
The product reviewed was provided at no cost. The opinions herein are the authors'.
Comments and Questions  
Welcome Below!
Please Like and Follow RoadTrailRun
Facebook:  Instagram: @roadtrailrun
Twitter: @RoadTrailRun You Tube: @RoadTrailRun
RoadTrailRun receives a commission on purchases at the stores below. 
Your purchases help support RoadTrailRun. Thanks!
The Carbon X is now available at the stores below 

RUNNING WAREHOUSE (6/1 Strong Stock Availability)
USA  Men's HERE  Women's HERE
Europe  Men's HERE  Women's HERE
FREE 2 Day Shipping EASY No Sweat Returns

Men's and Women's HERE
Join VIP Family and get Free Shipping and 15% in VIP Benefits on every order, details here


Anonymous said...

I just bought a Napali 2 for daily trainer. This is just perfect for faster/race day

geomaz said...

Wow!!!! What an amazing shoe guys!! First of all, I would like to thank you very much, for the super review!

Although I red the comparisson between the max road burst 4, I would like to aske you wich one is the fastest and more cushioned of the two. I am interested for marathon race. My pace is 7,5 / mile. Are you planning to have an other review (except the initial) of the maxroad 4?

Thank you very much, again awesome people at roadtrailrun!!

Sam Winebaum said...

HI geomaz,
Thanks for kind words! While I have run a lot in Max Road we are not yet authorized to publish our full review. In addition to me several other RTR testers will be running the Max Road. At that time we will more closely compare.
Sam, Editor
Sam, Editor
Thanks for reading Road Trail Run! See our page with links 100’s of in depth shoe and gear reviews HERE. You can also follow RoadTrailRun on Facebook, Twitter, YouTube and Instagram where we publish interesting run related content more frequently as well as links to our latest reviews.
Shopping through links on articles help support RoadTrail Run and is much appreciated!

Reza Saputra said...

Very interesting. I can see the use of these shoes for 24h track races.

Ville said...

Hi I have never used Hoka trainers. How you would size this if I am US8 in Boston and Adios, US7.5 in Peagus Turbo and US8 in Zoom Fly Flyknit and Epic React?

Thanks :)

Anonymous said...

Hi Sam.

any rumours or whistle out there from HOKA that they'll do a trail version of Carbon X ?? Hahahaha.
surely there's a prototype somewhere in camouflage like yours...Hahaha.. well hidden and are testing by some ultra trail runners out there :-)


Danny Yeo.

Sam Winebaum said...

Hi Ville, I would go 8 but must first ask why you sized down in Peg Turbo with its low toe box stripe?
Sam, Editor

Anonymous said...

Hi Sam.
How would you compare the fit of the Carbon X compared to the Bondi 6. I know the comparison isn’t obvious, but my rather low volume foot seem to fit that shoe, and it to should have a roomier fit.

Thanks for a great review.

Thomas from Denmark

Nick J said...

Thanks for the great article! Apologies if this has been covered elsewhere, but whats the word on the durability of this shoe as compared to the Nike vaporfly 4%? The Nike is obviously fantastic but I think a lot of people just can't drop $250 or so for a shoe that only has a life of around 100 or 150 miles or so (or so I've read online). With the understanding that the X is primarily a road racer, could this also function as a performance trainer and last upwards of 300/400 miles or so without losing much of its designed effectiveness?

Sam Winebaum said...

Hi Thomas,
Thanks for kind words! Haven’t run Bondi since v1. Tricky question. I think that you would be OK at True to size. Potentially but doubt he at half size down as the upper is so pliable. Sam, Editor

Ville said...

Hi Sam,

Thanks for your answer :)

For Pegasus Turbo. I don't know, it just felt longer shoe than other shoes for me. With 40.5 I have slightly more toe space than with Epic React in 41. I have about thumb width length there with Turbo.

Perhaps Turbo is just slightly wider, so it accommodates my foot better. My feet are semi-wide from the front with a narrow heel.

Oliver said...


I've asked someone one the Stryd facebook page who said after 600km the vaporfly still felt better than any shoe he owned. I've also seen a youtuber talking about running 1000km in a vaporfly without issues. It seems like the degradation could be pretty dependent on your running (perhaps your weight to shoe size ratio has an effect?). While I don't have them myself, I think the 100-150mi use is not necessary

Oliver said...

Hi Sam,

I'd be interested in hearing your thoughts on how it compares to the Zoom Fly Flyknit!

I love those - ran my first HM in them a couple weeks ago. My time was 1:31 to give you an idea of the paces I'm running. The Zoom Fly felt amazing my whole HM, but I hate how it feels on my normal run days.

I would love a shoe with a similar snap and ride to the Zoom Fly, but one that feels great at slower speeds. I'd been planning on treating myself to a pair of Vaporflys for a Fall HM where I hope to podium, but these feel like a more practical purchase.

Sam Winebaum said...

Great first HM time Oliver! Great questions. I find Carbon X considerably more cushioned in the forefoot and somewhat softer. A great combination could be Carbon X for most training except maybe fast workouts, VF for HM racing. That’s how I plan to pair!

Oliver said...

Thank you for your response, Sam. I really like the quality of your reviews and the multi-tester format.

Aaron said...


Thanks for another great review!

If you could only buy one, which would it be....Carbon X or Rincon?

Sam Winebaum said...

Carbon X but price difference must also be considered. Sam

Sam Winebaum said...

Thank you Oliver! Sam

David said...


Please help me with sizing on the Carbon X. Hoka sizing puzzles me a bit. I am a 12 in the Tracer, Hupana, and Clifton 3; 12.5 in the Clayton and Napali; and shockingly a 11.5 in the Mach 2. So, what would I be in the carbon X? Thank you. David

Sam Winebaum said...

Hi David,
Do you have a narrow low volume foot? The Mach 2 upper is if memory serves the least structured of the bunch you mention. Why did you size down there? and as described in the review the Carbon X has no overlays etc... I might guess 11.5 maybe 12 but not 12.5.
Sam, Editor

David said...

I sized down on the Mach 2 b/c I first ordered the 12.5 . . . it was so huge (I mean flippers!) that I thought it was an aberration. So I returned to RW, and ordered both an 11.5 and a 12. Clearly the 11.5 was a better fit and I now have 300ish decent miles in them including a 1.44 half marathon with my daughter. If anything I'd say they are a bit narrow but still plenty of room in toes. Very odd. The Claton 2 in 12.5 are as good of fitting shoe as I have ever had in both length and width. Thank you.

David said...

Sam, I'm just checking to see if you saw my response to your question. Perhaps I am an anomaly on the Machs. Thanks.

Jim Lukanich said...

I was sitting across the isle from you on the bus to the Boston Marathon start. So now I have the answer to the mystery white shoe you were wearing. Nice review. I hope your day went well. Mine not so much. :)
I am glad I was able to find your site. Really good reviews.


Jim Lukanich

Ville said...

Hi Sam,

Ordered Carbon X in US8 and enjoying it very much. I could probably be more comfortable in US8.5 for the longer runs. I actually think this US8 size is slightly shorter than my Pegasus Turbo in US7.5.

Maybe my feet are just super weird I don't know. But I definitely think the sizing lengthwise on Carbon X is smallish.

David said...

Sam, Just an update. I have been running in size 12 Carbon X. The good news is that they feel GREAT, the bad news is that they may be just a tad short. We'll see when I go long (6 is the most so far). I continue to be puzzled by Hoka sizing.

Sam Winebaum said...

Hi David,
Thanks for the update! I would be cautious about sizing up. You might try thinner socks? That front toe bumper is very minimal so has some give.
Sam, Editor

Ville said...

Hi David,

Do you also find Carbon X slightly short compared to the same size in Nike and Adidas for example?

Michael Busch said...

I am enjoying the shoes but was wondering if anybody had any issues with "hot spots" on the balls of their feet. My left foot/shoe is fine but my right foot, ball of foot, just behind the big toe is getting a bit tender towards the end of a 6 mile run. I can't tell if the front is too roomy, if the shoe might be too narrow, or ? I want to use them for mile first 20 miler this weekend but probably should do a few more shorter runs first to see if I can get the right shoe dialed in better. If I can't, the shoes might have to go back, even though I am really enjoying running in them.