K-Swiss K-Ruuz Shoe
View Image Gallery


An extremely lightweight racing flat.


An integrated "quick lace" system of some sort.


A solid racing flat for shorter distance races up to 70.3 distance.

Detailed Review

Lightweight shoes typically suffer from the same plague. Remove enough cushion to get the weight down light enough to be a racing flat and comfort goes out the window. Right? Not so with the K-Swiss K-Ruuz. It is a racing flat, so no, it's not a super cushioned thick soled marshmallow that you will want to wear for daily running. However, this featherweight of a flat packs a good bit of cushion into a 6.5oz package.

We have used the K-Ruuz for a wide range of race distances. We've done everything from sprints to 70.3 distance races in this flat and it has been a good performer for us. However, we opted for a little more substantial shoe (the K-Swiss K-Ona) for Ironman distance racing. We like the fact that the K-Ruuz seems to have found a good balance between weight and comfort.

The minimalist design of the shoe seems to help with overall running form. Maybe it's just because the shoe isn't heavy in the cushion department but the design seems to promote good form. With such a thin sole you will certainly be able to tell the difference when you are crash landing with a heavy heel or if you are landing with a nice efficient foot strike.

The K-Ruuz has been quite comfortable for running sockless in our tests. We have run several half marathons in these shoes sans socks. The place that may potentially cause some people trouble is where the Flow Cool strip is sewn above the toes. If this area could be heat welded (or put together in another way) to eliminate the seams that run on either side of the toe instead of stitched it would be a nice improvement. They are not as barefoot friendly as some of the other shoes in the K-Swiss lineup but we have had good luck with them.

The K-Ruuz seems to run a tad big in our experience. You may be able to size down a 1/2 size especially if you run bare down there (the feet, get your mind out of the gutter).

Breezy! Ventilation is definitely not something this shoe lacks. It has the K-Swiss Flow Cool System, which basically incorporates a bunch of perforations in the toe and the heel of the shoe.

The upper of the K-Ruuz is made completely of a mesh type material so the whole shoe really breathes very well. Something you are sure to appreciate in hot weather racing.

The K-Ruuz also has plenty of drainage holes in the sole. K-Swiss incorporates this into several models in their shoe line.

We like it. It's seems to be an often overlooked feature with other shoes. Why carry all that extra weight of sweat and water from aid stations if you can give it an escape route...we're just sayin'. Another nice feature from a T2 standpoint is the built in heel loop. It's made of a pretty soft material and it's attached to the back of the heel so it doesn't rub like some of the other shoes with integrated heel loops that we have tested.

At a mere 6.5oz the K-Ruuz is one of the lightest flats that you can actually stand to run in for any length of time.

Price Range
The K-Swiss K-Ruuz is right in the heart of the price range when compared to other racing flats.

TriBomb Bottom Line
A featherweight shoe that packs a serious punch when it comes to performance.


Manufacturer's Website