Vibram FiveFingers KSO

This is a heads-up on the size discrepancy for the different models of Vibrams.

In the process of ordering a pair of these for a friend, I ended up with an extra pair that otherwise would of been too small for her. This experience was good in that I was able to see for myself the difference in sizing convention Vibram uses for the KSOs and Flows versus their Classics and Sprints.

Vibram's size chart says I am a 41 in Classics/Sprints and a 40 in KSOs/Flows.

I own a pair of 41 Sprints and they are a *tad* larger than "fits like a glove" - pretty much perfect but with a little bit of give.

I tried on the 40 KSOs and they fit like a skin-tight glove. The 41s, in comparison, were WAY too big and my toes came out of the pockets easily.

I haven't tried on a size larger or smaller in the Sprint model so I am not sure what the fit difference there is but I was surprised that the difference in the KSOs was so noticeable; I totally expected for the recommended size 40 to fit the same way as my 41 Sprints do.

Edited to add on April 14, 2010

I realized I hadn't actually mentioned what I thought of the KSOs so I thought I'd do so now that I've had my pair for a year and a half.

I have worm my KSOs extensively in the time I have owned them and they are my favorite of my three pairs of FFs (the other are the discontinued Surges and a pair of Sprints). The strap and mesh combo help to keep my feet in completely and with no sliding around, even better than the strap arrangement of the Sprint model. I have worn these over all kinds of terrain: lawn, long grass, dirt trails, mud, gravel, sand, mountains, snow, ice, wood chips, sticks, leaves, asphalt, and even volcanic (pyroclastic) terrain and they are still my favorite shoes.

Some highlights:
• The shoe itself is very lightweight and I feel much more agile wearing them.
• The mesh does a good job of keeping most debris and grit out (though not as good with deep sand)
• KSOs dry out pretty quickly even after being soaked through.
• Worn a LOT & only now showing signs of wearing soles totally through after 1.5 years

I also accidentally poked a hole in the top of one of the shoes early on but the hole hasn't gotten any bigger, so despite the possibly flimsy looking appearance, the materials are more durable than you'd think.

Last weekend I wore these while out geocaching in the snow (I'd forgotten my boots). The temperature was in the high 30°Fs and the snow was compressed and crusted over so I didn't really sink in. At first my feet FROZE (as expected) but to my surprise (even having had extensive experience running in these in winter) I found that as long as I kept moving briskly, my feet warmed right up, even having been totally numb (note that I was also wearing a pair of Injinji toe socks with them at the time). I don't recommend these for heavy/sustained outdoor winter use by any means, but I wanted to use this example to point out that though your feet may feel cold initially, it is amazing how fast they warm up. This is probably due to the fact that when you wear FFs, you are actually using all your foot muscles, so they are working and creating heat.

Another commenter pointed out that they just wear these for daily stuff. I, too, wear mine for daily stuff - especially so. I find that I usually get pain in my knees if I have to walk around some big department store or Costco or something if I wear regular shoes. But I don't have any pain if I wear my FiveFingers. While outdoor activities sometimes require me wearing boots (snow, standing around in wet, cold weather), I find that when I'm doing general or indoor things, I nearly always wear my FFs.

Lastly a note on running/walking on asphalt or other manmade surfaces. A lot of people complain about how it hurts to run around on concrete and the like - this is obvious. However,  research shows that when you run barefoot and strike the ground properly with the front/ball of your foot you actually strike the ground with less impact and less shock to your joints as when compared to cushioned running shoes and heel-striking. The impact is a bit more noticeable in your metatarsals when running in hard surfaces in FiveFingers but you don't put NEAR as much stress on the rest of your legs. :)

Unlike most people buying these shoes, I'm not a runner or fitness enthusiast. I've just been having lots of trouble with regular shoes hurting my feet. The biomechanics of the VFF seemed right, so I thought I would give them a try. I'm an atypical user of this product. I wear my KSO's daily as my primary footwear, to work, shopping, and just about every other activity that isn't foot-threatening. I've been wearing them daily for more than a month now.

I initially purchased the size 43 based upon the instructions from Vibram, and found they fit "like a glove". Since my right foot is slightly larger than my left, it was a very firm embrace. Unfortunately, "fit like a glove" soon turns into "get my feet out of these things". It felt like my foot was being squeezed all day. Moving to a size 44 solved that. Be certain your foot has a bit of room in the size you pick. People with long toes need to watch this closely.

Comfort is a mixed bag. The shoes feel very natural as long as I am on my feet and moving. The initial discomfort caused by using new muscle groups passed quickly, and my feet are gradually "toughening up" so that extended walking on hard surfaces (sidewalks, etc.) isn't much of a problem any more. Today I walked about a mile to lunch and back on sidewalks without any discomfort.

I really notice the shoes when I am sitting. I still haven't gotten used to the feel of the separated toes, and I find myself constantly wiggling my feet to relieve pressure points caused by the separation. They aren't hurting my feet to the extent that other shoes did, but they aren't comfortable to the point that I can just forget them. But as I said above, activity almost immediately causes this to disappear.

Build quality is a mixed bag, too. The soles are holding up very well, even though I work in a downtown environment and do a lot of walking on concrete/asphalt along with the usual downtown debris. The uppers, however, seem to be very fragile. I scuffed the top of the big toe 3 days after getting the shoes, which left a hole in the material. Hopefully a bit of care will prevent more holes, but the fact that it wore through so easily worries me.

As for design, I think they would have been better off if they had made a 4-toe shoe, and allowed the last two toes to share a compartment. Most of my comfort issues and all of my difficulty putting the shoes on (it's still not a "just slip it on" move) come from that area. From a function standpoint, it would have made a better shoe. However, from a form standpoint it would have just added that much more oddity to a shoe that is already an attention grabber.

Update 2009-06-08

I've been wearing these daily for almost a year now (excluding about 4 months during the winter), and my experience has not changed much at all. The comfort level is the same, and unfortunately I have never gotten used to the feel of the individual toes to the point that I don't notice them when sitting still. I have also noticed that the seams between the uppers and soles can be uncomfortable over extended periods, but not enough to lessen the overall rating.

Regarding their longevity, they have held up extremely well. I have seen no real effects of wear & tear, even with regular washing. I now have 2 pair, and both have held up well. The hole I put in the big toe of my first pair is still there, but it hasn't grown appreciably with continued use.

Regarding fit & finish, Vibram has some work to do. The second pair I received has noticeable glue smearing around the seams in several places. Also, even though the two pair are the same size (44) according to Vibram, the actual fit is quite different. The second pair is noticeably looser and more comfortable than the original, even though they were purchased less than 2 months apart. It raises some quality control issues, and makes buying a new pair a bit of an concern - will I get a pair that fits well or not?

With practice it has become much easier to put the shoes on. Getting the little toe into the shoe is no longer a struggle, but it's still one of the more challenging aspects of this shoe, both for convenience and for comfort. Also, I have noticed that my little toe has a tendency to pop out during more active use, and it's very hard to fix without removing the shoe.

Overall, I'm still very happy with the shoes, and continue to wear them for all of my daily activities.