Every time I try a new shoe & it doesn't work out, I go back to my trusty Kinvaras, and though they are far from perfect, I can't deny that running in them gives me a feeling like coming home. Sure, it would be nice if it had just a LITTLE less cushion and the toe box were just a BIT wider (something I found myself acutely aware of after a few runs in the Altras & 'Drifts), but in general, I find that when I run in the Kinvaras, whether for three miles or twenty, I don't think about the shoes. They're comfortable, fit my foot really well (except for the toe box thing), and let me keep up good form without too much work, and that's not doing too badly as finding a solid running shoe goes.
So, as terrified as I am of suffering another major injury, it seems like marathon training (particularly when the base is not good) is a great time to stick with what works, even if it's not perfect. Obviously I haven't been going through tons and tons of shoes lately, but I recently I finally got down to two pairs of Kinvaras, one that's getting on in miles & will need to be retired soon, and one with ~150 miles on them, so it seemed like not the worst idea ever to have another couple of fresh pairs on hand.
But what, ho! No sooner had the thought of purchasing more Kinvaras crossed my mind that I received an email from my local running store that the Kinvara 5 had recently been released. Seriously??? I feel like the 4's have barely hit puberty and now they're being closed out at rock-bottom prices to make way for The New Hotness. Kinvara fans, should you stock up on the old model, or embrace the new one and get it over with
for another year?
This seemed like a GRAND setup for revisiting last year's Kinvara 3 vs. Kinvara 4 head-to-head challenge. You're welcome.
Here we have two brand-spanking-new pairs of Kinvaras, version 4 on the top and version 5 on the bottom, size 7.5B:
As you can see, many aspects of the shoe's construction have remained the same, as they did from the K3 to the K4.
In theory, the stack height & heel drop (22mm heel/18mm forefoot) are the same. (To me, the K4 feels juuuust a touch lower to the ground, the same way it did compared with the K3, but I don't have calipers so I can only go by the specs Saucony provides.)
Although the bottom of the sole is slightly different (see below), by & large the outer sole is built the same way & with the same shape. Both are built on a semi-curved, strobel last (perfect for the neutral supinator, AHEM) and feature a high-abrasion EVA midsole with a pretty traditional thickness, decoupled & beveled (forward-angled) heels, a Memory Foam heel pod (I still don't know what this is) & a material called PowerGrid in the heels.
Kinvara 4 on the left; Kinvara 5 on the right.
There are definitely a few differences as well:
1) As mentioned above, the K5 has additional carbon rubber (which they call XT-900) on the middle outer edge (blue) as well as very slightly more in the toe area:
2) The tongue and heel collar area have been radically changed. Instead of the FlexFilm™ used on the K3 & K4, the K5 uses a much thicker, plusher material called HydraMAX™.
At first, this change felt a little weird. Because the HydraMAX is so plush, my heels sometimes feel like they don't really settle securely into the heel counter at first. A few minutes into a run, though, I get used to it and it doesn't bother me.
3) Most of the upper is made of a "new, more flexible and durable lightweight mesh material" that feels stiffer/sturdier than the K4. (I have read in a few reviews of the K4 that some folks did not like its upper material & had issues with it cracking and tearing over time. I never had this problem with my K4's & liked it just fine.)
4) Pro-Lock lacing feature. Two small pieces of material with lace holes that are actually connected to the sole itself, not the upper, the idea being that using these holes will cause the shoe to hug your foot more securely.
I agreed with RunBlogger about this feature--if you lace up pretty tightly, you can feel this doing something, but it causes the upper to winkle in weird ways, and honestly, if I tried to run with my shoes laced that tightly, I'd lose circulation.
The specs state that the Kinvara 5 should weigh in at exactly the same as the Kinvara 4, and this is indeed what I found:
BUT. It is worth pointing out that the pair of K4's I used for last summer's K3/K4 comparison--same size & everything--weighed in at 6.4 oz, and a year & many miles later, they still do. (At this point I got worried about the consistency of the scale, but after weighing all the shoes several more times on different surfaces, the numbers never changed. So I don't really know what to tell you about that.) Both pairs of K3's I've weighed (also 7.5B) both consistently also weighed 6.6.
Kinvara 4 on the left; Kinvara 3 on the right.
As far as sizing, the K5's seem right in line with the 3's & 4's. I've always worn a 7.5B comfortably, and that size in the 5 feels exactly the same length-wise.
Width-wise....Well, here's where things get a little weird.
Back when I got my first pair of Kinvara 4's & wear tested them against the 3's, I kind of felt like they were just a *touch* wider in the toe box. Not dramatically, but just enough to slightly prefer the 4's. When I read reviews of the 4, though, just about everyone mentioned that the fit seemed a bit snug, particularly in the toe box, and for some people the difference was noticeable enough that it was a deal breaker for them. This was incredibly puzzling for me, because my experience was almost the complete opposite.
I haven't really thought about it much since then until I put one of these new pair of K4's on one foot and one of the K5's on the other. The difference was undeniable, though; the K4 felt narrow, particularly in the toe box, and the K5 felt a little wider.
So obviously, out of curiosity, I had to go back to that pair of K4's I compared the K3's to last summer.
Old Kinvara 4 from last summer on the right foot (your left);
brand-new Kinvara 4 on the left foot (your right).
Old Kinvara 4 on the right foot (your left); Kinvara 5 on the left foot (your right).
Again, the difference was unmistakeable. The old K4 is noticeably more spacious than the new one, particularly in the toe box, and feels about the same as the K5.
And it's clearly not just in my head:
I really don't know what to tell you about this. I might be tempted to say that a couple hundred miles of wear over the course of a year has "punched out" the older K4 a bit, except that I had the same impression of it when I first put it on last summer. If K4s have been feeling a bit snug for you, though, it's probably worth trying on a K5 at the same time, because you might find there's a little more room.
With the exception of the width issues described above, the two shoes felt exactly the same on my feet when I first put them on--same level of stiffness, cushion, stability, etc. I first took them out with one on each foot, and with the exception of the width in the toe box, it was difficult to discern any real difference. I thought the K5 might feel different because it just sort of looks like more shoe, but it weighs the same & feels the same, so maybe that's just in my head.
I've since run several times in the K4's, the K5's, and in one of each, and my initial observation holds: it is very, very hard to pinpoint a real difference besides the width. With one on each foot, I was aware for the first few minutes of how the heel collars feel different--the plush HydraMax of the K5 vs the lean, light FlexFilm of the K4--but it didn't take long for even that to fade into the background.
In terms of the stuff that I think of as the "ride" of a shoe--flexibility, cushioning, ground feel--they feel basically the same. The 5's apparently have a material in the midsole called Powerfoam "to create a cushioned and responsive ride," but if it makes a difference, I was unable to detect it.
So there you go. I wish I could remark on the durability of the two shoes, but since I am a) not running that many miles yet and b) rotate my shoes a lot, it'll probably take a while to get to that point. All I can really say on that point is that I have worn Kinvara 3's into 500+ territory without any trouble. At that point there is definitely a difference in the cushioning that you can detect if you put an old shoe on one foot and a new one on the other, so I generally stop wearing them for long runs after about 300 or so. But 4-6 easy miles around the neighborhood? I can wear a hole in the outsole before they start feeling uncomfortable. And mud stained, blood stained, & faded though they may be, even the uppers are still in perfect working order. So we'll see how far I can take the 4's & 5's.
I hope that helps!