La Sportiva Vertical K Review

A preview of the La Sportiva Vertical K.

By on August 1, 2011 | Comments

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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 running 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.

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.

Bryon Powell

Bryon Powell is the Founding Editor of iRunFar. He’s been writing about trail running, ultrarunning, and running gear for more than 15 years. Aside from iRunFar, he’s authored the books Relentless Forward Progress: A Guide to Running Ultramarathons and Where the Road Ends: A Guide to Trail Running, been a contributing editor at Trail Runner magazine, written for publications including Outside, Sierra, and Running Times, and coached ultrarunners of all abilities. Based in Silverton, Colorado, Bryon is an avid trail runner and ultrarunner who competes in events from the Hardrock 100 Mile just out his front door to races long and short around the world, that is, when he’s not fly fishing or tending to his garden.