I haven’t tried that many carbon-plated shoes yet. Mainly because I’m not very fast, so some carbon-plated shoes are just not a good fit for me. I did try the Saucony Endorphin Speed before and I did like the foam in that one, but the nylon plate sort of killed my feet, so I couldn’t run that far in them. I also tried the Hoka Mach 4, which doesn’t have a plate in it, but it’s basically the plateless version of the Carbon X3.
I had heard good reviews of the Carbon X and X2 and since I liked the Mach 4 so much, I really wanted to try the X3. Both the Mach 4 and Carbon X3 have a 5 mm drop and both are responsive neutral shoes. And both are really lightweight shoes with the Carbon X3 coming in around 188 grams in the standard testing size and the Mach 4 being 192 grams, so not a big difference there.
Both have rubberized EVA outsoles, not the most durable type of outsole, but I guess real rubber would add too much weight to the shoe. The main differences between the Mach 4 and the Carbon X3 are the upper and the carbon plate.
The Mach 4 has a mesh upper, not very plush, but comfortable enough, while the Carbon X3 has a one-piece knitted upper. I still don’t really understand what shoe manufacturers see in one-piece knitted uppers. Is it a weight thing or what is it? Almost all the one-piece knitted uppers had a bad fit. The only one that I sort of liked was the knitted upper on the Adidas Ultraboost 22.
I’m not a fan of the upper of the Carbon X3 and I don’t really understand why they didn’t just use the upper from the Mach 4 or something similar to it. It’s quite a thick knit and it’s too big, there is just too much of it even though I am wearing my regular size and the same size as I had for the Mach 4. I’m wondering if I could have gone a size down, but not sure if that would have been an issue length-wise. Due to the thick knit and the amount of room in it, it is difficult to get a good lockdown and as so often with one-piece knit uppers the knit then folds in on itself when you try to lock it down tightly. Which for me is creating a hotspot on the top of both my feet.
Another difference with the Mach 4 is the stack height. The Mach 4 has a stack height of 27 mm in the heel and 22 in the forefoot, while the Carbon X3 has a 32 mm stack in the heel and 27 mm in the forefoot.
There is also a difference in the foam. The Mach 4 has a Profly midsole, while the Carbon X3 uses a ProflyX midsole. This means that the midsole foam in the Carbon X3 is more responsive but also firmer than the Carbon X2 and clearly firmer than the midsole on the Mach4. The carbon plate is the same as they had in the previous Carbon X2 version.
The Carbon X3 is more suitable for a variety of paces than some of the other plated shoes on the market. You don’t need to be a super fast runner to wear this shoe, which is sometimes the case with some of the other super shoes out there. It is therefore also more suitable for a range of different runners. I do like the midsole, although it’s a bit firm, it’s a quick, pretty comfortable, and quite a stable shoe thanks to the wide platform. I just wish they would have gone for a different upper, like the one they had in the Mach 4. That would fix the lockdown issues and would definitely help with comfort. Who knows? Maybe in the next version.
If you want to pick up a pair of Hoka Carbon X3 of your own (or another pair of new running shoes), head on over to Running Warehouse Europe and use the code HEART10 to get a 10% discount.