La Sportiva Vertical K Review

In a radical departure from its recent models, La Sportiva has designed the Vertical K ($115), a radically light, extremely flexible trail racer that still runs like a shoe (in a good way) that will debut in Spring 2012. When I say radically light, I mean 6.5 ounce (185 gram) light. As for flexibility, I can easily tuck the toe into the heel and tortionally wring it with easy and through a wide range of motion in both the heel and toe. This is the kind of shoe that would make a La Sportiva team member or a fellow trail running editor jealous. How do I know that … because I saw it happen in the couple days since I received my pair.

La Sportiva Vertical K
[Please leave comments asking questions about the Vertical K, as I’ll be adding to this review as I log additional runs.]

Morphodynamic Midsole/Outsole
Last year, I previewed La Sportiva’s Morphodynamic technology. In short, the technology combines an ultralight, highly absorbent midsole material with an undulating outsole covered with sticky rubber. I enjoyed both Morphodynamic models, the Quantum and the Electron, but couldn’t help thinking that this technology had a sexier application in a trail racer. With the Vertical K, La Sportiva has gouged out lateral grooves that significantly reduce the amount of heavy rubber used in the outsole. (FYI, outsole rubber is the densest portion of a running shoe.)

La Sportiva Vertical K outsole
The lateral grooves, which correspond with the troughs in the wavy outsole, and the accompanying lack of rubber greatly add to the shoe’s flexibility. The only trail shoe in my extensive collection in the same league of flexibility was the New Balance Minimus Trail.

As with all of La Sportiva’s Morphodynamic shoes, the Vertical Ks lack a rockplate. The principle behind the MD midsole is that it’s soft and deep enough to absorb pointy obstacles, such as rocks and roots, that rockplates normally protect against. Be aware, that if you’ve run in either the Quantum or Electron, the Vertical K provides less push-through protection than these other models due to its thinner midsole and rubber-free areas in its outsole.

In another departure from the Quantum and Electron, the Vertical K features small lugs, akin to those on the Skylite and Skylite 2.0, that are overlaid on the wavy outsole. While I’ve not had a chance to test the shoes on mud and snow, these lugs shoe greatly improve the shoe’s performance in such conditions.

It’s worth noting that the outsole is made with FriXion XF rubber, the stickiest rubber this climbing shoe manufacturer uses its trail shoes. Having loved the tack of the less sticky Quantum and Electron, I can’t wait to go run more rocks in the Spiderman-power granting Vertical Ks. I know which shoes I’d take on a fall road trip to southern Utah’s redrock country!

For those who care about such things, the Vertical K has a 4mm heel-to-drop with an 18mm heel and 14mm toe height.

Upper
The Vertical K has a one piece structural upper that fits snugly, but with remarkable comfort. Playing with the upper in your hand you’d think it wouldn’t provide enough support, but that’s not the case at all. In a test run, it firmly held my foot in place. Although I’ve yet to go long enough to really put the shoe to the ultimate test, the lack of any primary focus of support in the upper could be a huge advantage in that it wouldn’t put bothersome pressure on any particular point on the foot. The seamlessness of the one piece upper will similarly reduce the chance of foot irritation. I admit to struggling to put the quality and fit of the upper into words. I’ll sum it up generally as saying that the upper is something you’ll want to slip your feet into and test for yourself.

La Sportiva Vertical K upper
According to La Sportiva, the one piece upper that “eliminates the need for a tongue.” However, the lacing area actually includes a tongue-like wrap that comes from the outside of the shoe and, on its unattached side, slips under the laces and into the instep portion of the upper.

There is a heel counter… if you count something that extends no more than an inch above the midsole a heel counter. That counter is asymmetric, wrapping two inches around the outside and three inches to the inside of the shoe.

There are three layers of toe protection ranging from a very lightweight overlay at the widest to a small rubber toe cap extending from the outsole. I’d describe it as minimal, but adequate.

The Vertical K features a scree gaiter covering the laces similar to La Sportiva’s Crosslite and Skylite models. This lycra piece wraps around the entire upper and is considered a gaiter protecting the entire shoe, but its primary use is certainly over the lace area.

Speaking of the lace area, this is one aspect I’ve had trouble with other La Sportiva models with lace covers. With those other models, I struggle to tighten the lowest laces by pulling the upper laces. In fact, I’ve cut the lace guards off some of my shoes. However, I have no such difficulties with the particular combination of thin laces and eyelet system of the Vertical K. Well done, Sportiva!

Call for Comments?
What do you think of La Sportiva’s Vertical K? Please feel free to leave a comment with any question you may have about the shoe.

There are 85 comments

  1. Ken

    The 110's definitely tear up my heel as well, there is a giant seam on the lateral side of the heel that I've been ignoring through 4 pair of 110's. I've finally had enough of the 110, I'm moving on. I'll be pretty hesitant about buying any NB shoes in the future, there are just too many design and quality issues. I've lost all confidence in NB.

  2. Ben

    RMS,

    Thank you very much for the Superfeet Black idea. I too have been in minimal shoes for some time now, and found the Vertical K's stressed my feet on long mountain runs more than I'm used to. Actually, they seem more flexible than my NB Minimus. Strange, given the increased cushion, but a real phenomenon nonetheless. Going to head to REI to pick up some insoles asap. Again, thanks for the tip!

  3. Eric Payne

    I'd like to follow up after some 6 months of using these shoes.

    The Vertical K's are still my go-to shoe, and I only venture away from them if I expect to experience terrible mud or have swollen feet. The most recent test was Hardrock, where I used these for the first 61 miles, then switched to La Sportiva XCountry's for the remainder of the race. Hardrock threw everything at my relatively new Vertical K's, and I had no complaints whatsoever about them. From smooth singletrack, to mushy and marshy areas, to steep and loose scree descents, to terrible babyhead jeep roads, I had no reason to switch shoes. After about 16 hours on my feet, my feet had swollen enough to cause my toes to start to bunch together and cause hot spots on my toes. I switched out for the roomier toebox of the X-Country and never looked back. If I had Vertical K's a half-size larger, I probably would have used them for the rest of the race.

    The moral of the story is that the shoes are fantastic. My main complaint is that the foam is a bit too soft, and seems to flatten out and allow rocks to poke through after only 200 miles or so, making for painful runs. Since there is no rockplate, I wind up finding myself wanting a newer pair, which could be an expensive proposition if it weren't for my pro deal, and perhaps that would be enough to cause me to look for another shoe…

  4. Simon Desvaux

    Hi Bryon,

    what do you think of using those shoes for the 'Diagonal des Fous' 170km with 10, 000m total climbing and same for descent. lets say i buy two pairs of shoes and change them after 50miles?

    1. Bryon Powell

      Hi Simon,
      I'll admit that I'd never consider wearing the Vertical K for any long ultramarathon, particularly one on such rocky terrain. However, if you train in the shoe a great deal and your feet are strong enough and rocks don't bother your feet, you could be fine.

  5. rms

    I'll follow up here that the Superfeet Black have become part of this shoe to me, acting as both arch support and as rock plate. This is a reversal of most trail shoes, which put the rock plate near the outside of the sole, and cushion on the inside. The effect is that the soft sole can wrap around rocks for grip, while the hard plastic of the insole gives confidence when impacting heavily on rock edges. It's still a pleasure putting them on for shorter distances.

  6. Phil M

    I don't understand why people call these narrow – they seem to run normal width, but very short. By the time I sized up a full Euro size to get a little toe room, they were downright wide. My feet are not narrow, but are low-volume. Typically, LaSportiva fits me very well. But, the stretch and wider cut of the upper mean I get a lot of movement on technical terrain. It's not a huge deal, but this squishy shoe doesn't cut it for me on technical, sidehilling terrain.

    For more typical hiking trails which are flat underfoot but steep and rough, I'm a big fan. These are lighter on my scale than Inov-8 X-Talon 190s (205g vs 215g, size 42.5 VK, 8.5US 190), but have way more cushion. My first real run in them was a 15k trail race with a long, rocky descent, and they kept my feet very happy striding out down that.

    Despite the weight, durability appears to be excellent. I took them running, hiking and scrambling over sharp Teton rock and they didn't get a scratch. They were also awesome on snow on that trip.

    So while they are not a quiver-of-one for me, they are the best choice for more terrain any of my other trail shoes. Only on very long days or very technical terrain do I switch to Raptors or X-Talon 190s. Unfortunately for my Vertical Ks, I do mostly long days and/or technical terrain, so they mostly get used for races and speed missions where I'm shaving grams from my kit.

  7. Eric Payne

    Do Black Superfeet change the fit of the shoe at all? I'm getting a pretty good fit right now, and fear that I might lose a bit of space by putting in a different insole.

    Can anyone else confirm that these work as a solid rockplate like RMS says? My main gripe with these shoes is that after around 150 miles, my feet get really sore from rocks below. The thinnest insole I can find to offer rock protection would really extend the life of these shoes..

    1. rms

      The hard plastic portion of the superfeet only extends forward to mid-foot, with the rest a tough but more flexible pad. I wish the hard plastic extended farther to protect the ball of the foot, which still will take a beating, but it's a major improvement over stock, regardless. I wore them again at Silverton 50k this past weekend, with a very rocky and steep 2nd half, and finished with slightly bruised balls of the feet but no other issues, and still love them. The integrated gaiter is pure genius: No other shoe I've ever worn keeps out dirt like this, and stows the laces to boot.

      The insole does take up room in the shoe, so I use my thinnest socks with plenty of lube all around the toes; sockless might be even smarter, though I've never tried that. In the MT110 I use thick drymax maxprotection socks, but those won't fit in VKs. The tight fit is a good thing in these shoes, they are a full inch shorter than Montrail Bajadas, which means less tripping and more nimbleness, with no toebump problems.

      Take all this with a grain of salt, as I'm a mid-pack guy, but I could wish a VK revision to slightly stiffen the forefoot, to reduce squirming and increase protection under the ball. On rocky terrain I find myself trying to land mid-foot or backwards, where I know the superfeet 'rock plate' is, which is not a good thing. If you checked Bryon's preview of the Helios
      http://www.irunfar.com/2012/08/best-trail-running
      They indeed will be adding a rock plate. This version looks to move to a more standard upper, which I don't like. The integrated gaiter and soft slipper forefoot in the VK upper is a major selling point for me, though the under-lacing padding could be tweaked to reduce the laces cutting into the top of the foot as it swells.

  8. koolaid

    These shoes look absolutely amazing, thats why I bought them. The only con is if your a heavier person the notched outsole feels bumpy on the bottom of foot. I replaced the extra thin insoles with some thicker ones and it seemed to help with the discomfort.

  9. Kymberly

    Hi, I have a high instep and often need to " build up " the inside of the inner sole to allow me more comfort is it possible with these ? They look great tho' I will have to track them down and get a hands on feel to them.

    Thanks for the great review

  10. Thecozz

    Hello,

    I tried to verticle Ks on yesterday loved the overfit. I do lots of road running, new to trail running.

    I actually had to go up one full shoe size for these to fit? form 9.5 to 10.5. width was great even in the 9.5 but short in the toe box. I guessi am wondering how much space is optimal to have from the end of your toes to the front of the toe box?

    thecozz

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