Last year’s model had a tight midfoot fit with the medial stitched-on tape rubbing against the foot. None of that is experienced on the Inspire 12. The tongue padding level hasn’t changed, so all of the fit improvement comes from cleaning up the inner sides.
Like many Mizuno’s, the Inspire 12 has an extremely broad tongue, which keeps it from sliding sideways despite the lack of a sleeve. And how exactly does a wide tongue help?
Tongue slide happens when it moves into the empty space between the foot and the upper during runs. A wide tongue fills up the gaps beforehand, so there’s no sideways space for the tongue to slide. Hence, it stays put, more or less.
The new laces are so much better on the Inspire 12. They feel extremely smooth and soft to the touch, and have a bit of an elastic quality to them. The heel portion fits identical to the Inspire 12, no change there.
Coming to think of it, the heel fit experience is very similar across most Mizuno models, be it the Creation, Prophecy, Inspire or Rider. All of these adopt a similar approach to counter molding, padding and choice of material, with predictable results.
Reflectivity isn’t much of a thing on any of the Mizuno shoes. There’s a microscopic Runbird logo on the heel which happens to be reflective, which is good as not having any.
Mizuno has an entirely different approach towards interpreting the motion control or stability shoe concept. Instead of inserting a medial post made of harder foam in its midsoles, it simply alters the design of its wave plate.
On the lateral side, the Wave plate has mellow profile with a gentle wave shape. On the medial side, the Wave design turns much more aggressive, featuring exaggerated troughs and crests. This is meant to make the inner midsole much more resistant to compression, and thus turning it into a motion control design feature.
It wasn’t always like this. Around 20 years ago, Mizuno had a quite a few shoes with traditional medial posts. Like the 1997 Mizuno Mondo Lite or Sumo Trainer, both of which had firmer, dual density midsoles. A year later, Mizuno released the 1998 Wave ST, along with another traditional dual density running shoe called the Mizuno Stratus.
Over time, Mizuno has stuck to using the Wave Plate, variating its use to accommodate models from the neutral and support category. So in terms of design execution, the Inspire 12’s wave insert is the same as the Inspire 11’s treatment. Ok, as a standalone component the two Wave plates aren’t exactly the same, and one will discern minor differences in the molding detail.
A casual glimpse might not reveal much, but the truth is that the Inspire 12 comes factory assembled with a slew of new updates. Lift the removable insole, and you’ll notice that the fabric lasting of the Inspire 11 is substituted with a foam kind.
The insole itself does not change. It is still soft molded foam, and the textile covering still comes with the luxurious hand feel recognizable by Mizuno loyalists.
The Wave plate is sandwiched between two layers of foam; the white midsole on top, and a colored lining beneath it. The red colored foam below the Inspire 12’s wave plate is much softer, while the upper white foam has firmed up, but not by much.
The softer red foam gets a new name, changing from last year’s combination of ‘SRtouch’ and U4ic to ‘U4icX’. Nonetheless, both are just compression molded EVA foam variants. By the way, U4ic is an abbreviated word-play on ‘Eu-phor-ic’.
The Inspire 12 modifies its foam stacking arrangement around the heel center. On the Inspire 11, the heel had a relatively evenly stacked design.
A lot happens under the Inspire 12’s forefoot. The outsole is still softer blown rubber, yet the geometry changes quite a bit. The Inspire 11 had three flex grooves and smaller pieces of rubber mounted on EVA foam, separated by generously exposed channels.
The Inspire 12 switches to larger outsole slabs, cuts down on one flex groove and actually increases the rubber thickness. This is another area responsible for the Inspire 12’s weight increase, along with the strobel switch and additional upper layering.
The rear-foot outsole retains the use of harder X-10 rubber in a horse-shoe shaped layout, and like the Inspire 11, rear-foot strikers will find the shoe noisy on harder surfaces.
And what does all of these changes do to the Inspire 12’s ride manners? Logically, a softer foam lasting and lower midsole heel should result in an all-around increase of softness, correct?
Wrong. Cushioning softness goes up but it isn’t evenly distributed. Moreover, the cushioning experience also depends on what you’re doing with the Inspire 12. If you’re just trying them on at the store or walking around, you will have a different opinion than the one you’d have when you actually go running in them.
The Inspire 12’s ride experience versus the Inspire 11 can be broken down in three parts. The first part relates to the change in the lasting material below the insole.
By switching to foam instead of fabric, the first layer of cushioning becomes softer. This is something you’ll feel when you’re wearing the shoe for the first time, or walk around in them. There’s more squish just under the foot, a sense of increased foam layering. Let’s leave this here for a moment.
The second part of the ride experience concerns the forefoot. One might think that a thicker blown rubber outsole will increase cushioning softness, but the reverse ends up being true here. Surprisingly, the Inspire 12 is actually firmer than the Inspire 11. And why?