Vibram Five Fingers KSO [Keep Stuff Out] — the Definitive Guide
The KSO at a glance —
- "KSO" stands for "Keep Stuff Out" due to it having a mesh covering over the top of the foot.
- The KSO retails for $85 for both Men and Women.
- Best-selling model for men — particularly all-black KSOs.
- Used mostly for running and hiking, but is the "do anything and everything" Vibram model.
About the Vibram Five Fingers KSO
Straight from Vibram: the Five Fingers KSO features "A non-marking 3.5mm Vibram TC1 performance rubber sole is razor-siped for a sure grip, and a 2mm EVA midsole enhances plating protection and comfort."
The "razor-siped" rubber sole on the KSO is the standard, original VFF sole (same as with the Classic, Flow, and Sprint models). Razor siping is just little jagged cuts that expand when the Vibram rubber sole is bent or flexed. This can increase surface grip on many surfaces. That said, the standard VFF sole can be slippery in muddy conditions due to the lack of cleating (See the KSO Trek if you want a cleated sole)
The KSO's upper covers the foot up to the ankle preventing debris from getting inside the shoe. Of the standard soled Vibram models (Classic, KSO, Sprint, and Flow), only the Flow and KSO cover the top of the foot.
The KSO's 2mm of midsole is a distinguishing factor as compared to the Sprint and Classic, which have no midsole, and will reduce, if only slightly, the barefoot feel as compared to these models.
Finally, the Vibram Five Fingers KSO is secured to the foot by a single hook-and-loop system with a nylon strap that goes around the heel and is tightened via a velcro strapping mechanism on the top, instep of the foot. With only one velcro point, the KSO's attachment method is simpler than both the the Sprint's three-point and the Flow's two-point velcro attachment system. The primary drawback of this method is that it can cause wear in the nylon strap where it folds on either side of the foot.
- Covered, strapped design makes the KSO perform well in high-intensity applications, including watersports, while keeping out debris.
- The KSO looks more like a "shoe" as compared to Sprints or Classics.
- Can function as the only Vibrams you own, doing just about anything you can throw at them.
- Covered top makes putting them on more difficult; the difficulty is usually reduced with practice.
- Covered top can reduce breath-ability, making your foot warmer than with the airier Sprints or open-topped Classics.
- 2mm of additional EVA as compared to Sprint or Classic models will reduce ground feedback.
Vibram Five Fingers KSOs can be used in virtually any application imaginable. They have been used for wear in moving water, for trail running as well as running on concrete or asphalt, for many fitness activities including weight lifting/training, climbing, hiking, biking, walking, etc. Others use them casually or for travelling. The VFF KSO is the jack-of-all trades Vibram Five Fingers model as depicted in story and photos in the many, many user stories and experiences running, hiking, traveling, below.
Men's KSOs are available in the following color combinations:
Women's KSOs are available in the following color combinations:
Detailed KSO Vibram Five Fingers photos:
Check out the definitive guide to sizing Vibram Five Fingers. Having perused that document and figured out your size, there are certain noteworthy considerations for the Vibram Five Fingers KSO:
- Your size in KSOs may not correspond to your size in other VFF models, particularly Sprints and Classics. If you know your Sprint/Classic size, KSOs should size one down, though this is only a rule of thumb and your mileage may vary.
- Generally, you should not need to size up to wear five-toed socks with the KSO.
- If you have a high instep, you should give special consideration to trying on a pair of KSOs in person to insure proper fit. Some color combinations have been found to run tightter than others — specifically, the all black KSOs seem to be more snug on top of the foot. The same concern would apply if you have larger ankles.
Cleaning and care:
Machine-washable but air dry. Advanced stench may require white vinegar soaks or oxyclean treatment!
Modifications and other considerations:
- Fortify your KSO hook and loop straps in style using the Marley Mission tape mod.
- Make your black KSO Five Fingers dressy by blacking them out.
- Keep your pants off the ground (the hems of your pants at the heel) when wearing KSOs using S-Biners
- Got webbed toes? Turn your Five Fingers into Four (or three or whatever) Fingers
- men's Vibram Five Fingers KSO review at Birthday Shoes
- women's Vibram Five Fingers KSO review at Birthday Shoes
- 1200 miles in review of KSOs at Rambling Outside the Box [Running centric review]
- 900 miles and 350 miles reviews of the KSO at Red Rocks, Blue Sky [Running centric review]
For more KSO reviews, check the comprehensive Five Fingers reviews list here.
Where to buy
Vibram Five Fingers KSO User Experiences and Photos
Below are listed Vibram Five Fingers KSO user stories and reviews. Each link leads to a separate post written by a KSO user about their experiences with the KSO model. Stories cover many of the things VFFers are doing in their Vibram Five Fingers KSOs. Click around and see what you could be doing in the full-coverage barefoot alternative KSO!
- Run a 100K race in KSO Five Fingers with Leif
- Run a 100km Trail Race in Singapore in Vibram Five Fingers KSOs with Bernard
- Run a 10K Race with a Smile on your Face in KSO VFFs with Ronald
- Run a Thanksgiving Gobble Run 10K in 5 Finger KSOs with Haley
- Run a 5K race in KSO VFFs with Bob
- Run your personal best in a 5K race in KSOs with Jocelyn
- Run and Joggle the Philly marathon in KSO Five Fingers with Joe
- Run your first marathon in black KSO Vibram FiveFingers with Chad
- Run a Vegas half marathon in Five Finger KSOs with Jawa
- Run a half-marathon in KSO V5Fs with Alan
- Run a half-marathon and make friends in KSO VFFs with Bien and Ben
- Run the San Antonio half-marathon race in KSO Five Fingers with Tyler
- Run your first half-marathon in New York City in KSO Five Fingers with Ben
- Set a PR running a half-marathon race in KSO Five Fingers with Lynn
- Run the Baltimore half-marathon race in Vibram Five Fingers KSOs with Chris and Bien
- Run a 5.5 mile road race in KSO Five Fingers with Brandon
- Run a 5 mile race in KSO VFFs with Ryan
- Run in the snow in Vibram Five Finger KSOs with Jeff
- Run cross country in KSO Five Fingers with Courtney
- An Urban Race / Scavenger Hunt Run in KSO VFFs with Jenn
- Run trails in Houston in KSO VFFs with Eric
- Trail run the San Pedro River Valley in black KSO Vibram 5 Fingers with T
- Trail run in KSO VFFs with Michael
- Running in KSO Five Fingers is Cake with Luau
- Hike Brazil in KSO Five Fingers with Josh
- Hike to the South Arete Summit in VFF KSOs with Maria
- Hike the Incline in Colorado in KSO V5Fs with Steve
- Hike Eastern Oregon in KSO FiveFingers with David
- Hike the Canyons in FiveFingers KSOs with Josh and Barrett
- Hike upstate New York with Ben and M-Cheezy
- Hike to the highest point in New York (Mount Marcy) in black KSO Vibram Five Fingers with Axel
- Hike Newfoundland in KSO Five Figners with Noah
- Hike about Bethabra Park in North Carolina in KSO Five Fingers with Calvin
- Fly through security no questions asked in KSO Five Fingers with Justin
- Frolic around Indonesia in KSOs with Erik
- Honeymoon in Mexico in KSOs with Levi and Linz
- Forge Mountain Streams in Maui in KSO Vibram Five Fingers with David
- Swim in natural Hawaiian pools in KSO V5s with Erin
- Explore the Great Wall of China in black KSO Five Fingers with David
- Walk around Beijing, China in Five Fingers KSOs with Ben
- Travel around the Southwest United States in KSO Five Fingers with Kim
- Photograph Berlin in KSO Vibrams with Brian
- Enjoy Fiji in FiveFingers KSOs with Kevin
- Enjoy Jamaica in KSO Five Fingers with Justin
- Shop an Afghanistan market in black KSO VFFs with John
- Vacation in Canada in black KSO VFFs with Piz
- Enjoy a day at the Casino in KSOs with Sandra
- Tour Turkey in KSO Vibram Five Fingers with Javier
- Take a road trip up the California Coast in blue camo KSOs with Sal
- See Norway through your KSO VFF-clad feet with Mark
- Get married in the dunes in KSO Vibram Five Fingers with Jason
- Walk on air in FiveFinger KSOs (skydive) with Bobby
- Tandem Skydive in KSO Vibram Five Fingers with Phillip
- Power lift (Squats, Dead lift, etc.) in KSO Vibram Five Fingers with Tim
- Mountain bike Austin in VFF KSOs with Lou
- Whitewater rafting the Ocoee River in KSO Five Fingers with Patrick
- Be a billionaire presenter in KSO V5Fs with Sergey Brin
- Play on the playground in KSOs with Erik
- Rock out on the bass with your band in KSOs with Ian
- Lead tours around Barcelona, Spain on Segways in KSOs with Edgar
- Wall Crawling / Indoor Climbing in KSO Five Fingers with Carl
- Juggle five balls at once in Five Finger KSOs with Joe
- Appear on a Barcelona Radio Talk Show in KSOs with Edgar
- Grab the family to go find a Christmas Tree in KSOs with Alan
- Give your feet a rest after climbing to the top of Castleton Tower in KSO with Bob
- College is hard. Relax after class in black KSO VFFs with Derek
- Yoga moves - headstands - in blue camo KSO Five Fingers with Jawa
- Go to a Dallas Cowboys Football game in KSO VFFs with Adam
- Attend a Penn State in KSOs with Sandra
- Teach mechanical engineering in black KSO VFFs with Jawa
- Go fishing in KSO Five Fingers with Shawn
- Go to work in black KSO Five Fingers with Kevin
- Comedy and improv in KSO Five Fingers with Rocco
- Play kickball in Five Fingers with Justin