The adidas Ultra Boost ST replaces the Adistar Boost as the premium support shoe in the adidas line-up. The sample we saw (pictured above) has adistar boost embossed on the shoe. The catalog reads Ultra Boost ST. We can only guess what the box will have on it (for example: the Oregon 10 had Oregon 11 on the shoe, but Oregon 10 on the box and in the catalog). But let’s get back to the shoe.
The Ultra Boost ST basically adds a bit of stability (support) to the Ultra Boost, you know the shoe that was stupidly billed as the greatest running shoe ever. Runners know there is no such thing as the greatest shoe, but we all have our favorites. And much to my chagrin, I really like the Ultra Boost, but still hate the advertising.
There are three things I love about the Ultra Boost: 1. 100% Boost midsole. There is something special about the full Boost midsole, more so than the Boost/EVA combination of other adidas Boost shoes. It is forgiving on impact. Not soft per se, but it does dissipate shock really well and man does it return energy. Although it’s somewhat heavy, I prefer the shoe for slightly faster days or standard runs, but not for easy days. On easy days, I want something I can settle into, whereas the Ultra Boost is always itching to go faster. 2. Primeknit upper. It is as comfortable as my favorite socks (Balega). The Primeknit has a great stretch quality to it that hugs my foot really well, and in my opinion, is more comfortable than the Nike Flyknit. 3. Supreme flexibility. The one-piece outsole with cutouts throughout allows the forefoot to flex like a slinky.
There are two things I dislike about the Ultra Boost: 1. Super shallow toe-box. It is so shallow, I thought I was going to have to go up a size. I didn’t and the length is fine, but I was concerned my big toe might poke through. However, after 120 miles there are no signs of wear. 2. Midfoot plastic cage thingy. Other than adding weight to the shoe, I don’t really know why it’s there. Sure, it allows the shoe to have laces and it does secure the foot, which is needed because the Primeknit will not do that on it’s own, but it seems oddly out of place.
So why all this talk about the Ultra Boost? As I mentioned, the Ultra Boost ST is essentially the Ultra Boost, save for the fact that the Boost midsole is engineered in a multi-density fashion to minimize excessive pronation. It also has an odd looking piece of material on the medial side of the midsole to suggest the shoe has support. But it is more for show; the function is coming from the multi-density Boost midsole.
The Ultra Boost ST does carry over the three elements I enjoy in the Ultra Boost. It addresses the two things I don’t like. The toe-box is a not as low and the plastic cage thingy is replaced by a fabric cage thingy. The toe-box change is welcome, but I think more work needs to be done to execute a cohesive look and feel in a midfoot wrap feature. There are also two other changes of note: 1. The upper pattern changes slightly just after the toe-box to add a touch of support to the forefoot fit. 2. While the outsole pattern is very similar to the Ultra Boost, it is filled in on the rear medial side to aid in stability, and the rounded points of the Ultra Boost outsole have been flattened. I do not expect the changes to make the two shoes feel all that different, and if that’s the case, the Asics Kayano is about to see a worthy competitor.
Preliminary Tech Specs
Stack height: 32mm heel, 24mm forefoot, 8mm heel-toe offset
Weight*: 11.1 oz (men’s size 9), 9.8 oz (women’s size 7) *Provided by manufacturer