Asics Gel Kayano 25 vs Kayano 24 Running Shoe Comparison Review

by Sportitude
30 May 2018

Fresh off the shelf, Josh reviews and weighs up the Asics Gel Kayano 25 running shoe against its predecessor the Asics Gel Kayano 24, demonstrating the differences for 2018.

Whether you're hitting 5km a week or 30km and beyond, this latest evolution of Kayano deserves worthwhile consideration when tossing up options to support an overpronating running style.

It features Asics' innovative cushioning systems; FlyteFoam Propel and FlyteFoam Lyte to fly over the pavement, alongside other key changes to the fit, midsole and outsole configuration.

Check out the full review with transcript below.

Hey guys, Josh from Sportitude here today with our shoe review video.

The Asics Gel Kayano 25 has just landed in the warehouse and we're pumped about this shoe. I've been lucky enough to have a pair for about six weeks now. I've done a few runs in them to get a bit of a feel for them and I ran in the 24s as well.

From my own personal experience, I'm going to tell you about the features that have changed from the new 25 versus what we're used to from the 24. It's going to take a while so go make yourself a cup of tea and let's get stuck in.

I'm going to hold up my slightly used 25. I've been on two 5km runs, nothing over the top, just to get a feel and read on this specific shoe.

I can tell you right now at home that the new 25 has got a new outsole configuration and midsole configuration. There's a slight tweak in their arch support, and there's definitely tweaks in the upper and in the heel counter.

They don’t want to recreate the wheel because change is a bit scary and too much change can put a few people off. They’ve stuck to the integrity which has made this shoe a very iconic shoe, especially here in Australia.

I'm literally going to start from the bottom and we're going to work our way up. I'm going to show some feature differences between the two as we go through this video.

I've got the 25 in my hand. We've got a pretty aggressive outsole in the sense that it looks like there's a fair bit of traction and grip in comparison to the 24.

Asics have kept what they've called their Guidance Line. You can see that line on the outsole that comes through the middle of the shoe and curls around to the forefoot. Same thing for the 24 to the 25. The differences are mainly in the thickness of the outsole rubber.

The 25 outsole configuration has more depth in it. Roughly to the naked eye, there's 1mm - 2mm extra rubber on the outsole. That will not only provide extra durability underneath but a wee bit of cushioning too. The extra rubber provides a little bit of impact guidance when your foot hits the ground.

All of these features are linked together, so I'll continue speaking about the outsole. The 25 has three flex grooves through the forefoot.

Remember this shoe is designed for the overpronator, the runner that comes down whether it be on heel strike or midstance, and rolls in over that arch and loads up that first big toe on toe-off - so pronation, arch rolls in. Essentially that's what this shoe is engineered for.

Underneath the shoe, there's an encapsulated piece which sits between flex groove one and two. That alone gives that toe-off extra durability. That rubber holds the outsole together and gives the foot extra support when you're toeing off. I wouldn't rely on it, but it provides a little bit of extra support.

Let’s compare it to the 24. Again, three flex grooves, same as the 25. However, between flex groove one and two there's no encapsulated rubber. As you can see as I bend the shoe, there's a more flexible outsole configuration. That being said, it doesn’t mean the 25 is going to be stiff, because I'm going to start talking about the midsole now.

Let's get cracking on the midsole. A fair bit has changed but I'll stick to the basics first - stack heights. For the men's Kayano 25 we're running with a 22/12 offset, so 22mm in the heel, 12mm in the forefoot and a 10mm heel-to-toe gradient. In the ladies however it's 24mm/11mm, so there's a 13mm heel-to-toe gradient.

This has been debated for a considerable amount of years. I personally think Asics and a couple of other brands out there are doing a great job in splitting the engineering between men's and women's. Our musculoskeletal system is quite different so it's vitally important they tweak the shoes to suit specific runners.

That slight difference in offset is vitally important and it's good to know they are considering the biomechanics for men's and women's and putting it into the right shoe.

Moving onto the midsole we'll talk about the cushioning system. Asics have got a two layered midsole essentially. They've got a new system which is called FlyteFoam Propel and FlyteFoam Lyte.

I'll talk to you about FlyteFoam Propel first. It's probably easier if I hold the men's shoe because it's split between the two colours, you've got white and then you've got the blue.

FlyteFoam Propel is this blue layered midsole that sits on top of the midsole at the back around the heel and it becomes thicker as you come down to the forefoot. FlyteFoam Propel is a more responsive FlyteFoam from their range.

FlyteFoam Lyte is the white section at the back. It's designed for a heel striker, so you want your softest foam between the two at the back half of the shoe. The white foam comes around through the outsole and as you can see in the medial side, it's white as you come around.

It does change densities when you get to the arch support. It's not identified anymore but we'll get to that in two ticks. That is their lightest and softest foam between the two. It gives a fair bit more cushioning.

The cool thing about the FlyteFoam Lyte is that Asics have a good story behind it. There's quite a bit of natural waste that goes into the engineering of that FlyteFoam Lyte.

They’ve told us it’s made up of about 40% of organic fibres which has been pulled from sugarcane waste. We talk about brands being more environmentally friendly and Asics are happy to put their hat on that and say "yes, we are".

That’s the cushioning systems. Asics wouldn't be doing their job if they didn't put in Gel cushioning somewhere, so of course they've got that visible Gel in the back half in the heel strike zone. It splits the two FlyteFoam components so that Gel cushioning gives your foot a bit of impact protection when it hits the ground.

They still have their forefoot Gel which sits right underneath your first metatarsal joint, however on the Asics shoe it doesn't actually say. Usually when you pick up an Asics shoe there's a bit of a process map, where they have their cushioning etc. Usually they'd have Gel written on the forefoot, side or lateral side just to let you know there's forefoot Gel.

They haven't done it this year but don't be alarmed, it's there. That's the midsole in terms of the cushioning component.

Let's talk about the arch support now. DuoMax arch support in the 25 versus Dynamic DuoMax in the 24. The main difference between the two is the DuoMax support from my understanding is lighter. There's no real over the top benefit for going for Dynamic DuoMax over traditional DuoMax.

DuoMax in the 25 is a little bit lighter and covers a little bit less of the shoe. It's hard to tell with the naked eye. Again, Asics and other shoes gone by have used different coloured foam densities to identify where specific support sits. You're just going to have to trust me on this one.

On the 25 it runs right through to where the white foam sits. The DuoMax doesn't come into play on the FlyteFoam Propel. It sits on the FlyteFoam Lyte midsole component and slightly angles down to the forefoot.

The reason they've been able to do that and take away the Dynamic DuoMax is because they have the FlyteFoam Propel which is a more responsive midsole. What they’re trying to achieve is a slightly more responsive connection between your foot and your midsole and what we call the braking zone.

You've got the impact zone, then the braking zone is that phase of your running gait when you're trying to slow down the movement of the foot before it gets ready and prepped to toe-off.

By having the responsive midsole that sits on the forefoot layer you can slightly shave away the amount of arch support after that braking phase, utilising the performance of the midsole to get your foot in a stable position to get ready to toe-off. Very clever by Asics to do that, you can reduce the effect of an arch support system by using different densities of midsole to create that effect.

There's a lot to talk about. Hopefully some of this is sinking in. If it's not please add a comment in this video at any stage and myself or one of our support team will get back to you as soon as we possibly can.

Midsole moving to the upper. I’d like to talk to you about the fit of the shoe because that is critical. For those of you that might have watched the 23 versus 24 video, there was quite a bit of change to the fit of that shoe.

23s were quite narrow and shallow through the forefoot. 24s made them a little more generous. The 25 is again a little more generous through the forefoot.

In terms of the shape, we found with the 24 it still came to quite a point through that forefoot, although Asics created a bit more depth in the upper.

There was an issue with some runners finding the forefoot pinching too much through that toe-off phase. Remember we still want our foot to be able to splay and disperse that shock on toe-off. We don’t want to be cramped and tight inside the shoe, that will cause problems as we keep running.

In the 25 we've got a new engineered midsole so naturally they’ll put it on a different platform when they press this midsole. They’ve made it a fraction wider potentially, but I haven't got my ruler out and measured that.

Asics have been able to create a slightly more rounded forefoot, but not to the point where we're talking a box shaped forefoot. It has a little more to offer in the volume and the platform support when you're toeing off. 

I do like the 24 and 25. Personally, the first thing I noticed as soon as I put my foot in the 25 is that I could lift my toes a little bit, there's wriggle space and I thought 'this is kind of nice, I like this'.

I usually like a secured fit on my foot, but I did like the freedom of the 25 through the forefoot, so that’s one feature they've changed which is noticeable in the first fit of the shoe.

The upper has just a little bit of underlay support. After the navy mesh there's a couple of speckles of red. That's the underlay system which runs underneath the breathable mesh which connects to the midsole.

Asics are concentrating on getting the support from the ground up or under your foot down, however the upper will hold you in as best as it possibly can.

When you go for that midstance phase those underlays which are connected from the midsole to the eyelets of the shoe lacing system gives the foot extra hold and stability when you're running so they don’t fall off or move off that platform.

We've got a slightly wider toe box, we've got the underlays which they had in the 24 as well. You can see the yellow lines are a bit more visible in the 24, the underlays on the medial side. It comes into play again in the 25, just slightly more hidden.

The 25 has a nice amount of depth in the navicular region. That's a critical part in the overall fitting of the shoe. You never want a shoe that is too tight in the navicular region.

When you go from impact to breaking, your foot can sometimes pitch and stretch up and therefore we don’t ever want to be restricted through this region. It can create all sorts of issues.

Put your hand up at home if you get pins and needles when you're going for your run. We all have, more often than not.

Being too tight around the navicular region or if the lacing system is too tight or too shallow with the engineering of the shoe, it can minimise the blood flow down to your toes and back.

Going for an hour run or 10 minutes into a run, if it's too tight you get that pins and needle effect. Stop, loosen your laces and you start to question the overall fit of the shoe.

It's nice and deep though the navicular region which is great, still getting that support though.

Just coming back, we've got the external heel counter which Asics do a great job with. Looking at the 24 versus the 25, from the rear angle of the shoe they have that external device which sits around the shoe, then on the medial side they look very similar in regard to how much real estate that back half carries and the support that actually entrusts.

As you come through to the lateral side it's almost the same configuration. Where they’ve tweaked it is to create a slightly better fit in the base of the heel with the new 25s. They don’t have this crossbeam which was sitting in the 24. The crossbeam is there to give the foot a little more stability when it came down to the ground.

Instead, the 25 almost have an internal capsulated heel counter. The external device is doing the job of holding the foot in, but the light blue lines and navy blue lines at the rear of the shoe indicate the internal extra support device that's slightly giving the shoe more support when it comes down to the ground.

When your foot hits the deck, you want the midsole to do the job of impact guidance from the base up as you come through midstance.

But if your foot or your calcaneus, the base of your heel is moving around when your foot hits the ground going through the midstance phase, it can cause all sorts of delayed onset issues as you go up your shins, your knees and your hips.

You really want your calcaneus to be nice and solid when it hits the ground. That’s the effect of this external heel counter device.

All in all, I really like the new update. There's always been a difference between the GT-2000 and the Kayano. There's subtle differences, sometimes it's been harder to explain than others depending on the year and the models coming out.

With the 24 and the 25 there's quite a split, obviously with the new GT-2000 6 which is still on the market, having that FlyteFoam midsole. But now we're looking at the 25, there's never been such a big difference between the Kayano and the GT-2000.

The Kayano 25 fits like a true Kayano shoe should. I mean that because Kayano runners are probably running consistent speeds, long distances and are out on the road for a considerable amount of time.

If you’re a runner that likes to run 5, 10 or 15km a week that’s still OK, you can use the Kayano. If you're a runner that is really hitting the pavement quite hard, you're out there 30km plus a week and running at consistent speeds, the Kayano is a really nice shoe because it offers a consistent feel the whole way through the shoe.

Now, if you’re a runner that wants to vary speeds and look at doing tempo runs etc., you're probably not going to like the performance of the 25.

The reason being, and I've said this for the 24 versus GT-2000 review as well, is because they're a slightly heavier shoe, not like a gumboot but slightly heavier. For the speed tempo runs it's not going to feel as light and responsive on your foot as the GT-2000 for example.

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There we have it guys, until next time happy running and we'll see you soon. Take care.