Earlier this week, I received a pair of Vibram EL-X LS and I wanted to share my thoughts on this highly-anticipated shoe. Why is it highly anticipated? Because the “EL-X LS” that’s available in youth sizes right now is what will be available in all sizes come 2014 as the KSO EVO. If you recall for the post about them earlier this year, the KSO EVO replaces Vibram’s most popular shoe, the very versatile KSO. It features a speed lace system that is similar to the Bikila, Spyridon, and KMD LS, which allows for easy entry and a snug fit and the KSO EVO’s thin sole provides excellent flexibility and ground feel. Like I said, the “KSO EVO” is scheduled to be released in Spring 2014 and isn’t officially available yet.However, if you fall within a narrow range of sizes, you can pick up a pair right now! That’s because a model called the “FiveFingers EL-X LS” was released in youth sizes earlier this year. Indeed, the EL-X LS is available to buy online (See: Zappos, which actually has them on sale). Since some youth sizes overlap with adult sizes (up to a men’s 42) and I fit these sizes, I was able to pick up a pair even though the adult-version EL-X LS or “KSO EVO” won’t be available until 2014. The FiveFingers KSO EVO is officially “out” and for sale as of mid-February 2014! Save for differences in color and available sizes, the EL-X LS is the same exact shoe as the upcoming KSO EVO! For the purpose of this review and since I’m no youth, I’ll be referring to the EL-X LS as the “KSO EVO” for the rest of the review. Again, they are the same shoe just different sizes. Full review and photos after the jump! Background: this review was written after running 30 miles on asphalt (in freezing Cape Cod weather!) and 40 treadmill miles, mixed in with some gym work, including weights and an automatic rock wall. My other Vibram shoes include the Bikila LS, KSO Remix, KSO TREK, and EL-X. I have relatively flat feet and wear a size 41 for all Vibrams. For additional sizing reference, I also wear a size 41 for Vivobarefoot’s minimalist offerings.


What's under your Christmas tree this year?
What’s under your Christmas tree this year?
The KSO EVO may be the best toe shoe Vibram has ever offered. It carries on the lofty name of its predecessor in style and vastly improves upon the EL-X that it’s based on. No other shoe in the lineup strikes such a perfect balance between weight, flexibility, and stability. The KSO EVO has replaced the EL-X as my “go to” shoe for just about anything. Vibram uses initializations for the naming of some of their models. In the case of the KSO EVO, the name is meant to signify an evolution (EVO) of the original KSO (keep stuff out); a shoe that aims for versatility as an “all-around” model that can fill multiple roles, including running on both roads and trails and for cross fitness. In addition to the naming fun, this shoe is also known as the EL-X LS, where EL-X stands for “Entry Level Crosstrainer” and LS stands for “lace system”.

vs. FiveFingers EL-X

The FiveFingers EL-X in black on the left; EL-X LS (for Youth) / KSO EVO FiveFingers in blue on the right.
The FiveFingers EL-X in black on the left; EL-X LS (for Youth) / KSO EVO FiveFingers in blue on the right.
As you can see from the photos, the KSO EVO is more of an evolution of the EL-X than the original KSO. It can be best described as an EL-X with added features for a more secure fit, both in the heel and the around the foot. For more information on the EL-X, please check out Justin’s initial review! The major differences between the KSO EVO and EL-X are:
  • The welcome addition of Vibram’s speed lace system
  • Added structure around the heel for a tighter fit
  • Before the KSO EVO, I would have said that the EL-X is the best in the FiveFingers lineup, followed by the Bikila LS. However, the KSO EVO trumps both shoes by being a near-perfect combination of the security of the Bikila LS and the weight and ground feel of the EL-X.
While the EL-X is the featherweight of the vibram lineup at 4.23 oz for a size 43, the KSO EVO is only a shade heavier at 4.9 oz. By comparison, the Bikila LS can almost be considered heavy at 6 oz and even the Seeya LS clocks in above the EVO at 5.07 oz. Overall, the KSO EVO is the second lightest shoe in the Vibram lineup.

The Upper

The KSO EVO features the same polyester stretch mesh upper as the EL-X and the Seeya. More breathable than the coconut active upper used in the Bikila LS, the stretch upper in the KSO EVO is very comfortable and fits like a glove (well, my foot anyways). Because the KSO EVO has such a breathable upper, I would not recommend it for cold weather fitness activities. Of course, that didn’t stop me from running six miles each day in 25 degrees, but the original KSO, Bikila, Spyridon, KMD, Flow, Maiori and Lonta all provide better insulation for the cold. In addition to the stretchy mesh upper, the KSO EVO also features the same “painted on” rubber first utilized in the EL-X to add a little structure to the shoe and keep it tight on your foot, but these painted sections hinder breathability in the sections of the mesh where they are present. Unlike the EL-X, which has nothing else but the mesh+painted rubber combination to keep the shoe on your foot, the KSO EVO has the addition of a lace system to maintain tightness and does not rely on the the painted-on for security, so its usage seems redundant and inhibits breathability. It may also cause hot spots, which I experienced on my instep where there is some of the painted-on material (near the Vibram logo). This went away after a few runs, but it was quite the initial annoyance. I had a similar experience with the EL-X and I think both shoes just require a little bit of a break-in period to eliminate any hotspots or tightness due to the non-breathable rubber material. Overall, the upper for the KSO is very breathable and comfortable, but I did experience a short-lived hotspot on my instep, which rubbed some of the unnecessary(IMO) rubber material on the shoe.

The Lace System

The addition of speed laces to the EL-X base dramatically improves the functionality and fit of these toe shoes.
The addition of speed laces to the EL-X base dramatically improves the functionality and fit of these toe shoes.
The KSO EVO features the same closed-loop bungee and velcro strap as other LS shoes for FiveFingers (minus the Seeya LS and Speed, which have traditional laces). With the lace system, the the KSO EVO should be able to accommodate a wider range of foot shapes, including those with flat feet (like mine) and high arches. I also found that the KSO EVO does not look quite as “strange” as the EL-X because the lace system and tongue of the shoe makes it a little taller, where-as the EL-X is a very low attention-getting shoe. I find the lace system that Vibram uses to be far superior to traditional laces. There is no need to tie and knot floppy laces; just grab the bungee, dial in the right fit, slap the plastic but onto the velcro strip and you are good to go! If there was any issue that I found with the lace system is that the opening of the shoe and tongue is not as large as other Vibram LS shoes. Whereas I am able to quickly slip into my Bikila LS, the KSO EVO requires a bit of a struggle to get into it at first, but it becomes easier as you break in the shoe. In addition, the reinforced leather portions of the shoe around the collar and heel are not stretchy, so that also makes it a little more difficult to get the shoes on. Overall, the lace system is absolutely perfect for finding a perfect fit for a variety of feet. You will wonder why you bothered with velcro or traditional laces in the past.

The Sole

The KSO EVO sole is the same as the EL-X, the most minimalist FiveFingers sole available.
The KSO EVO sole is the same as the EL-X, the most minimalist FiveFingers sole available.
The KSO EVO has a similar sole to the EL-X. They are both part of the “max feel” category from Vibram, alongside the women’s Alitza. They all feature a zig-zagging, sliced up Vibram rubber sole that provides good traction in a variety of surfaces and is miles ahead of the smooth sole of the original KSO. With the “max feel” line, Vibram has truly put itself back ahead of other “barefoot” shoes in terms of flexibility and ground feel. The KSO EVO has a “max sole thickness” of 4.7mm which includes a 2mm EVA foam insole in the figure and something like a 2.7mm Vibram rubber outsole. The EVA compresses pretty quickly and will begin to mold itself to the shape of the bottom of your foot after running just a few miles, making the overall stack height of the shoe even lower as a result. With such thin soles, both the KSO EVO and EL-X are very floppy and you can roll them up in any direction with a single finger. You can even roll up one shoe and cram it into it’s opposite (but not, like, evil version), if you so choose to. While all vibrams allow you to flex your toes up, only the EL-X and KSO EVO (and the KSO Remix) allow for you to flex your toes down, which is an amazing feeling and a testament to how thin and flexible the shoes are.
Flexing the toes down in the KSO EVO is not a problem!
Flexing the toes down in the KSO EVO is not a problem!
Ground feel with the KSO EVO is fantastic. You can feel every little thing as you run, including tiny pebbles and even the stems of leaves as you jog to your heart’s desire. The sole provides just enough protection, while maintaining a near-barefoot experience. Because the sole is so thin, it can help you figure out proper running form and technique. By comparison, when I run in my Bikila LS shoes, I definitely notice that I can land a little harder because of the extra padding that the Bikila has over the KSO EVO. I will caution that the KSO EVO may not be a good choice for those who are looking to transition into minimalist running as its thin sole does not allow for a lot of room for error in running form. If you heel step in the KSO EVO, you will hurt yourself. Something like the KMD or Bikila may be better suited for anyone planning to make the transition from bulkier shoes to Vibrams, while the KSO EVO is more of a shoe for barefoot enthusiasts looking to hone their barefoot technique.

The Heel

The KSO EVO has a much improved heel structure compared to the EL-X.
The KSO EVO has a much improved heel structure compared to the EL-X.
The single best improvement the KSO EVO made over the EL-X (aside from the lace system) is in the heel fit. Vibram greatly enhanced the sections that wrap around your heel to make the KSO EVO a fantastic shoe for running and making sharp turns. In the comparison photos between the EL-X and KSO EVO, you can clearly see that Vibram added additional height to the heel and structure to the “wings” on either side of the heel (See this photo), which really hugs the back of your foot and completely eliminates the heel sloppiness you may experience when running with the EL-X or Seeya. When running with the EL-X, I was constantly reminded of the heel as it moved up and down with every step (luckily, no hot spots ever developed). Despite that issue, the shoe was adequate for running in a straight line at moderate speeds, but the EL-X was definitely a let down if I ever had to quickly move around. With the improvements found in the KSO EVO, I can confidently run and make turns as quickly as I please. The lace system and the heel “wings” are a perfect combination for security, stability, and a glove-like fit with the KSO EVO.


I have not had enough time with the KSO EVO to assess the durability of its upper or sole, but I’ve run about 100 miles with the EL-X and it’s held up perfectly with zero issues and the sole has yet to show any wear. By comparison, my pair of Bikila LS have–all things considered–held up very well after about 750 miles, but they did sprout a small hole on the inside of the big toe, which I was able to patch with some shoe goo and about 40% of the treading has worn away around the outer toes and the ball of the foot.


It seems furry friends almost always like toe shoes.  This guy is no exception.
It seems furry friends almost always like toe shoes. This guy is no exception.
Vibram has really outdone itself this time around. I was initially skeptical when I heard that they were replacing the beloved KSO with the EL-X-based KSO EVO. All of the skepticism was swept aside after I went on my first run with them. The KSO EVO strikes a balance between the fit and security of the Bikila LS, the heel tightness of the KMD, and the thin and flexible sole of the EL-X. The improvements Vibram made on the EL-X were absolutely fantastic and it has become my new favorite running and gym shoe. My only regret was that the KSO EVO was not available in black at the time of writing this review. If you are a Vibram fan, you have to give the KSO EVO a try. It is “out” for sale now and runs $90 MSRP. Also, for the curious, you can see all 2014 Vibrams for sale here. PROS
  • Excellent groundfeel
  • Very lightweight and flexible
  • Super Secure fit
  • Breathable upper
  • Possible hot spots that will go away after the break-in period
  • Vibram Funk persists