I love racing flats. They’re like sports cars – light, fast, and sexy. As part of the Wattie Ink. Elite Team, and K-Swiss as one of our sponsors, I knew the K-Ruuz would be my go-to racing shoe. I had previously raced in the K-Ruuz 1.0. I liked it a lot. It was very, very light, very flexible, and very responsive. It was a great shoe, for me, for a half-Ironman distance, half-marathon, or shorter.
The K-Ruuz, now in version “1.5”, is still super light, super flexible, and super responsive. It weighs less than 6 ounces in a men’s size 9. I hate to use anything analogous to the “hanging arm test” of bikes, but you really notice how light it is when you pick it up. You also notice that there just isn’t a lot of shoe, but that is what I like about it. The shoe’s sole thankfully remains the same, retaining its quick, responsive feel. It retains its 10mm heel/forefoot differential. Considering the new Blade Light Run 2.0 now has an 8mm heel/toe differential to better facilitate a midfoot/forefoot stride, I suspect a future version of the K-Ruuz will have a lower heel. Others, who are used to training in shoes with a lower heel, may also feel like this is too much, at least on paper. The fact of the matter is that there isn’t a whole lot of shoe period. If you notice anything, it will be how little you notice.
The ride is extremely extremely responsive. It is also pretty firm. For a lot of athletes, it might be too firm, but whether you feel like you need more cushioning depends on your race and your individual preferences. For many athletes, this may be a great racing shoe for sprint and Olympic distance or for 5k or 10k running races. Lighter athletes with good mechanics may find it sufficiently comfortable for half-Ironman distance, half-marathons, or even Ironman distance and marathons. Many of the K-Swiss professional triathletes, including Tim O’Donnell, Miranda Carfrae, and the Raelert brothers race Ironman distance in the K-Ruuz. A lot of my Wattie Ink. teammates use the K-Ruuz for short course racing, but use the Kwicky or Blade Light Run for long course racing. I used the Blade Light Run for Ironman Texas, because I wanted more cushion for the marathon, but the K-Ruuz remains my go-to racing shoe for anything shorter. At what point you want more cushioning depends on you, your running mechanics, and the demands of your particular race.
Other features in the midsole include drainage holes for when you dump water on yourself or when race volunteers decide to douse you with water. The heel also has a bit of posting, intended for some support when your stride starts breaking down. It isn’t much though, and I would hardly consider this a stability racer. Finally, the K-Ruuz has a removable insole. If you are like me and you wear orthotics, this is a must, and it is a welcome feature that is missing from many of the current “minimalist” shoes.
The K-Ruuz 1.5 sports a completely different upper from the original version. It remains very light, with a lot of mesh and you can still see through it in a lot of places. K-Swiss has incorporated its Ion Mask treatment, which prevents the upper from absorbing water. It won’t keep water out of your shoes, and it won’t keep your feet dry, but it will keep your shoes dry and any water that goes in will drain out thanks to the drainage holes. K-Swiss also added its seam-free technology. This is not the soft sock-like lining that Zoot uses (which always reminded me of moon boots), but it leaves a little more room in the shoe for your toes. I cannot guarantee that you can run in this shoe and never get a blister. Everyone has a different foot and every shoe is just a little bit different. If you want to race without socks, it helps to train without socks first with a shoe like the Kwicky or Blade Light Run 2.0, which both lack interior seams as well. The rubber section over the toebox, which was the source of some major blisters for me, is thankfully gone.
Unlike most racing flats, the tends to run big. I normally wear a 9 1/2 or 10, depending on the shoe, and wear a 9 1/2 Blade Light Run 2.0. However, I wear a size 9 K-Ruuz 1.5.
These are racing shoes. Do not expect to get a lot of miles out of these shoes. Still, even if you wear them for your weekly speed workout and for racing they should get your through a season (or at least most of a season).
Below are some additional articles about racing flats and whether a racing flat is right for you
I love these shoes. Nonetheless, shoes, and racing shoes in particular, are highly individual. If you need a racing shoe with stability, the Saucony Fastwitch, Zoot Ovwa, or Brooks ST5 might be better options. If you want a stability racing flat with a lower heel, the Saucony Fastwitch is a good choice (it has a 4mm heel). If you want a neutral flat and you are dead set on a shoe with a lower heel the Zoot Kiawe (6mm heel), Nike Zoom Streak (4mm heel), and Saucony A5 (4mm heel) are all good options. If you want a softer feel and more cushioning you may want a shoes built more along the lines of a performance trainer or “distance racer,” like the K-Swiss Blade Light Run, K-Swiss Kwicky Blade Light, Saucony Kinvara, Brooks Pure Connect or Pure Drift, or the Brooks Launch. However, not all of these shoes may work well for sock-free running.