Shoe Review: Kinvara 3 vs Kinvara 4

If you keep up with Saucony, you might have heard that the Kinvara 4, the updated version of my beloved Kinvara 3s, was recently released.

Do I already have more running shoes than I realistically need right now (ie, more than zero) in the rotation? Maybe.

Are there already three fresh pairs waiting in boxes above my closest? Perhaps.

Am I not still at least a couple of weeks away from being able to do any activity that requires running shoes? Fair point.

But. The fact that my excitement over new running gear has returned is significant in terms of my mental health, kind of like when you've been sick for a while & finally get your appetite back. It signals that I'm feeling optimistic, that I can anticipate having some potential use for running gear in the next few weeks.

Any time a new version of one of my favorite shoes is released, I always face the same agonizing choice. Do I...

1) Get myself a super cheap pair (or two) of my old, tried-and-true favorites, or...

2) Accept that the times they are a-changing and try out the new version, reasoning that, if I hate them, better to know sooner than later?

I was feeling extra bold the other night, I guess, because after a little internet bargain hunting, I found myself rejecting the tyranny of the 'or' and embracing the genius of the 'and.'

BOOM.

Saucony Kinvara 3

Saucony Kinvara 4

(Sidenote: While I was writing this, I was like, "Oh, I'll just add a link to the blog post where I reviewed the Kinvara 3's & talked about how awesome they were & how much I loved them." Then I realized I never actually wrote that post. So....sorry. The 10 second story: They're light, comfy, awesome, & I love them.)

Having both pairs is exciting to me because I've rarely had two versions of the same shoe to compare to one another directly, and when I have, it's usually been a brand-new pair of the new release and an older, slightly beaten up pair of the old version. That makes it really hard to objectively compare the two.

Obviously, it's going to be a while before I can do a real, true comparison on the road, but let's get the basics out of the way now & know that I'll have a "field test" comparison for you once I'm up and running again.

Construction:

First, let's get something straight: The Kinvara is NOT a minimalist shoe. It's not. Stop calling it that. This is a minimalist shoe. This is a minimalist shoe. Even this is sort of a minimalist shoe. But nothing with a sole nearly an inch thick under heel is minimalist.

Yes, it's on the lighter side, and yes, it has a smaller-than-usual heel drop. That makes it a performance shoe, NOT a minimalist shoe. Case closed.

As shoe updates go, the construction seems freakishly similar. We have for both shoes...

• Lightweight FlexFilm™ upper (if you've never touched a pair of Kinvaras, this stuff is actually pretty cool, like really really thin vinyl over really really thin mesh)
• 4mm heel drop
• Semicurved last (= perfect for the neutral supinators among us)
• A high-abrasion EVA midsole with a pretty traditional thickness (high-abrasion EVA is a lightweight outsole alternative to heavy carbon rubber)
• Outsoles of mostly blown rubber (white, lime), with a few tiny triangles of carbon rubber (pink, purple - for traction, maybe?)
• Decoupled & beveled (forward-angled) heels
• Memory foam heel pods (I don't know what this is, but supposedly they both have them)

Looking at them side by side makes the similarities even more obvious:

As for the differences:

• While both have a 4mm heel drop, the K4 is 1mm closer to the ground (22mm heel / 18mm forefoot) vs the K3 (23mm heel / 19mm forefoot).
• The beveling on the K4 is ever so slightly more dramatic
• The K3 uses a material called ProGrid (which I think is what most of Saucony's shoes use) in the heel, while the K4 uses something called PowerGrid, which is supposed to be a bit lighter. According to the marketing copy, it also "offers even smoother transitions and an improved overall ride."

K4 comes in slightly lighter for size 7.5. Is this because of the PowerGrid / ProGrid difference? For what it's worth, this pair of K3s weigh in exactly the same as my older pair.

• Re-designed upper (with the exception of the heel counter which I will discuss below, I think this was mostly just cosmetic)
• A subtle difference in profile. This is the biggest visual difference I see. If you look at both from the side, you can see that the K4 curves upward through the forefoot / toe more dramatically than the K3.

I'm really curious about this change. Any shoe gurus out there have any theories?

Fit:

So obviously I can't run in these guys yet, but I did put one each foot & do a little walking / trotting up & down the hallway. As far as I can tell, the fit is identical. Not just "pretty close," but absolutely freaking the same. Both shoes are 7.5 & feel exactly the same size. The width feels the same through both the heel & toe box. The upper seems to fit the same way.

There was only one noticeable difference that I felt while walking around in them, and that was that the heel counter on the K3s felt slightly taller, which gave the sensation of my heel sitting slightly deeper in the shoe. A shot of both shoes from the back confirmed this.

A small but noticeable difference.

Feel:

I have read a few things here & there with people talking about the K4 being OMG soooooo much cushier or soooooo much stiffer or waaaaaah why did you ruin my K3s, but I have to say that as far as that goes I really could not feel a single difference in terms of how the shoes felt.

And I tried. I tried stepping different ways, flexing my foot different ways, landing on my heels, landing on my forefoot...There really just was no difference whatsoever in terms of cushion, stiffness/flexibility, or responsiveness. Of course I have the advantage here of comparing two brand-new shoes, side by side straight of the box, and I wonder how much of people's perceptions about this are influenced by 1) what they remember the K3 feeling like or 2) what their old, broken-in K3s feel like.

Granted, I haven't actually run in the K4s yet, so we'll see if that changes my mind in a few weeks. (Update - You can find part two of my Kinvara 3 / Kinvara 4 show-down here.)

• Have you tried any version of Kinvaras? Thoughts?
• If you're a die hard Kinvara fan, have you tried the 4s yet?
• Has anyone else done an A / B comparison? I would love to hear your thoughts!