The Evolution of the KSO
The new KSO EVO is a new and improved version of Vibram FiveFingers’ (VFF) original KSO, which stands for “Keep Stuff Out”. It has a newly designed upper with a speed lace and tongue as well as an all new outsole. Is it a better minimalist shoe than the original? Read on to find out…
Price: $90.00 USD
Width: Narrow to Wide
Sole Thickness: 4.7 mm
Drop: 0 mm
Weight: 3 3/8 oz or 94 g
Insole: None included
Sizing: 36–42; Full sizes only
Category: Minimalist Sandal and Casual
Comfort & Fit
The KSO EVO is wonderfully comfortable. This shoe fits very much like a glove for your feet. The toe pockets fit my stubby toes perfectly and the speed lace clamps the shoe down for a snug fit for narrow to wide feet. The lace also has a lock to keep it in place and a bit of Velcro to keep it from flapping around. The faux suede material collar opens much wider than the previous model to allow a wider range of foot widths to get into the shoe. The collar is also minimally padded providing a very smooth edge around the ankle. The tongue is slightly padded to protect the top of the foot well from any binding of the laces. Although the seam is quite thick where the tongue attaches to the upper, it has never bothered the top of my feet nor caused any blisters, even when soaking wet.
There is no removable insole but there is 2 mm of EVA between the outsole and the anti-microbial Drilex footbed.
Barefoot Feel & Function
With a total sole thickness of 4.7 mm, this model has a middling thickness for VFF but still very thin for the minimalist market. The Max-Feel outsole design is fabulously flexible and easily bends around any ground contour. It has a grip depth of about 2.5 mm so even very small rocks can be felt underfoot. The outsole rubber is quite sticky and provides more than enough traction for any man-made surface and dry natural surfaces.
Weighing just under 100 grams, they feel like snug socks rather than shoes. Feet function naturally with the glove-like fit and flexible outsole.
The upper is made of a polyester mesh with plenty of airy holes for breathability, a faux suede around the collar, tongue and at the heel, as well as a rubbery material overlay on the toe pockets and in strips in strategic areas across the top and sides of the shoe. Although the mesh isn’t as widely spaced as the Vi-B, the upper functions wonderfully at keeping stuff out and allowing sweat to escape. Although not water resistant, they do allow water out of the shoe as fast as it goes in. In addition, they work great at creek crossings because they keep the stones out while not causing any blister issues while soaking wet.
There is no break-in period for these shoes and if they get dirty, they are easily machine washed and air dried.
The outsole is 3.5 mm thick and made of the same XS-Trek rubber compound as the Vi-B, which is advertised to offer “30% more adherence to smooth surfaces than previous formulas.” Despite the pictures on the Vibram website at the time of this posting, the outsole pattern is the same as the Vi-B with longitudinal grips rather than horizontal ones. Vibram has informed me that the pictures of the outsole will be updated shortly.
As there is also 2 mm of EVA underfoot, the KSO EVO doesn’t have as much ground feel as the Vi-B, but there is still plenty of flexibility to easily bend around ground contours and rocks. As the KSO EVO is a more versatile shoe with its enclosed upper compared to the ballet flat-inspired Vi-B, I can understand why a minimum of extra cushioning might be quite welcome to most customers, especially if using them for wet and rocky adventures.
There is no arch support designed into the shoe allowing feet to function naturally whatever the terrain you wear them on.
The overall quality of the materials seems excellent and other than the smallest visible glue marks at the toe pockets, there are no manufacturing flaws in the review pair. The upper mesh has squares of rubbery material attached to the tops of the toe pockets, which I suspect is an effort to increase the durability of this high-wear area while still allowing maximum flex in the material, in addition to their being a nice design detail. This same rubbery material also crosses across the top of the foot and along the sides, and likely aids in structural stability and upper longevity. It’s a great improvement over the original KSO and will likely allow the EVO to last longer with heavy use.
I like the look of the new KSO EVO far better than the original model. The laces look sharp, function better, and more comfortably than the original Velcro strap. The rubbery material overlays also add style in addition to structural and material durability. The faux suede lends a look of quality and improves comfort. All the improved design changes seem to increase the KSO EVO esthetics as well as either comfort or durability. I am thoroughly impressed with the changes and find this new model a significant improvement over the original.
The KSO EVO is offered for men in red/black, blue/black, and all black and for women in grey/pink and (thankfully) all black as well.
If you like the least amount of shoe between your foot and the ground no matter what the adventure, the KSO EVO might be the minimalist shoe for you. With less than 5 mm underfoot, you will feel plenty of rocks but also be able to easily bend your feet around the smallest of ground contours. With their glove-like fit and excellent lace attachment, these shoes are great for anything from errands around town to trail hiking to creek crossings. They have good breathability allowing them to be used as an effective minimalist running shoe as well. As I am the sort of person who likes as much ground feel as possible, I know that I am going to get PLENTY of use out of the new KSO EVO.
At $90.00 USD, the KSO EVO is priced at the low end of VFFs and the minimalist market overall. Considering their improved durability and extreme versatility, this is an excellent value for an all-purpose minimalist shoe.
I bought my first pair of minimalist shoes in May of 2008 and they were a pair of original VFF KSOs. They introduced me to the world of minimalist footwear and changed my life. The KSO EVO is the new and improved model and VFF created a shoe worthy of being the successor of my beloved first pair of minimalist shoes. They “Keep Stuff Out” better than the original but they also fit and stay in place better, are easier to get on, have far superior traction, and will likely be longer lasting. They look nicer, too (although I’m more about function over fashion with regards to my footwear). If you only want one pair of minimalist shoes or are looking for a great “first pair”, the KSO EVO is a wonderful model to include in your minimalist footwear toolbox.
To order or find out more about the KSO EVO, check out the Vibram website.