I have been seriously enjoying my KSO Vibram Five Fingers — my second pair. The "KSO" is an acronym that stands for "Keep Stuff Out." I had previously purchased and reviewed Vibram FiveFinger Classics back in May 2008, and as a result, John from KayakShed had gotten in touch and graciously sent me a pair of the "Taupe/Palm" Vibram Five Fingers KSOs. That color combo is more of a "grey/green" with gray rubber Vibram soles, as you can see here fresh out of the box (For all KSO colors, see the definitive guide to KSO Vibram Five Fingers):
Design Differences — The difference between the Five Fingers KSOs and the Five Fingers Classics (Here is a picture of the Classics)is that the KSOs have an ankle-sock-like elastic seal, fully cover the top of the foot (these two work to keep stuff out of the inner parts of the VFFs), and are secured via a velcro strap that tightens over the top of the foot. The strap runs behind the heel, which allows you to tighten up the KSOs at the back of the foot, as well. This design makes for an all around snug (and quite comfortable) fit.
Another point of difference to the Classics is that the Classics use an elastic band/bungee cord that can be cinched and tightened at the heel. On the plus side for the Classsics, this design allows for a minimal amount of foot coverage and makes the Classics the easiest to put on — sort of like the "flip flop" of the Five Fingers line-up. Unfortunately, when cinched, the band on the Classics can put pressure on the front top of the foot, which may be irritating on longer periods of wear (Again see the Classics picture for reference).
The primary drawback to the KSO design, which is unavoidable, is that the covered top forces a smaller entry point for your foot, making navigating toes into toe holes trickier. Having said that, after probably ten "wearings" it became easy to put the KSO Vibram Five Fingers on, and of course, the benefit to having a more cumbersome entry point is that the KSO design affords greater security on the foot. Once your KSO Vibrams are on your foot, they stay on — Keep Stuff Out, Keep Vibrams On!
Some have asked me if the KSOs are hot — they are not. The mesh covering seems to breath well and the regular Five Fingers fabric is ultra-thin.
Functionality — All of the typical FiveFinger benefits you find with the Classics apply to the KSOs and then some. That means you can run, sprint, play, workout, jump, etc., in the KSOs just like the Classics. Like any FiveFingers, KSOs afford the freedom of effectively being barefoot but with the added protection of a thin, non-supportive-but-protective, flexible Vibram rubber sole. Thanks to the more robust velcro-based tightening mechanism, the KSOs inspire confidence — moreso than the Classics when running sprints or dashing up or down stairs. Whereas the Classics sometimes feel like the heel might flip off, the KSOs (and the Sprints for that matter) are completely locked onto your feet.
As for the "Keep Stuff Out" part of the KSOs, they work pretty well—mind, they could have really gotten nasty on the ankle seal by employing a beefier elastic band, something akin to what cycling socks use. However, this would have been overkill for many, considerably less comfortable, and would have impaired the improved stylishness.
Style — Here I model the KSOs, note the turn in the middle (I know, I should be a professional foot model!):
Herein lies perhaps one of the greatest benefits of the KSOs over all other varieties of Vibram Five Fingers: they actually look more like normal footwear — particularly when worn with pants. Of course, they are still FiveFingers, which means that everyone will still be staring at your birthday shoes thanks to the articulated toes. But the full-foot covering of the KSOs makes them much more palatable from a style standpoint, and I have frequently worn mine around town. This, in combination with the added security provided by the KSOs, that makes the KSO model the number one selling VFF — particularly for men. And of the color combinations, VFFers everywhere love the KSO Five Fingers in black.
I actually love my Classics and probably get more "wear time" in them than the KSOs due to their ease of entry and overall maximized minimalist feel (See my detailed thoughts on why the Classic Five Fingers are awesome here).
What can you do in KSO Vibram Five Fingers?
Just about anything. KSO Vibram Five Fingers are the "do anything" Vibram model.
Go hiking. Run a marathon or a 10K. Mountain bike or attend a football game. They're good in the water, too. This hardly scratches the surface of what you can do in KSO Vibrams. For 70+ user-based photo stories, take a look at the comprehensive page dedicated to KSO Five Fingers.
Sizing — Generally, KSOs size one down from Classics and Sprints though in my case, I actually wear the same size across both KSOs and Classics. You might have guessed it, but sizing VFFs is tricky. I recommend consulting the sizing methodology Vibram provides, which is covered in great detail at the birthdayshoes wiki, so make sure you consult it and get the right Five Fingers size! It's also useful to consult before going into a retailer as often times the employees don't know the nitty-gritty complexities on sizing VFFs (and there are differences between genders -- a M40 isn't the same as a W40 and women's sizes, which men can wear and vice versa, generally are slightly more narrow).
Conclusion and Summary — Simply put, the KSOs provide:
- more versatility than any other VFF. The KSO can do anything the Classic or Sprint can do and much of the same things the Flow can do (it's just less warm),
- a solid tightening method via the velcro strap, which both inspires confidence and is comfortable, and
- the full-foot coverage makes the KSOs more stylish (particularly with pants). This seemingly trivial difference is actually very important because more stylish VFFs make you much more likely to wear your birthday shoes out in the world at large. More wear means freer, stronger, healthier, and happier feet. And that's the whole point, right?
So even though they are around $10 more than the Classics, I think the KSOs are worth the added expense for most individuals — particularly if you are going for functionality more than comfort. You can get them at KayakShed here.
See our post on "Barefoot Running Shoes" to see where KSOs fall on our Barefoot Running Shoes Continuum.
Questions? Comments? Be sure to leave feedback below!