Adidas Terrex Agravic Speed Ultra review: conquering downhill

The Adidas Terrex Agravic Speed Ultra is a high-performance trail running shoe designed for downhill dominance. Built for long-distance races, the shoe boasts a lightweight build, a wide forefoot platform for enhanced control during descents, and advanced cushioning technology for superior energy return.

Despite its high price and a few sizing issues, its innovative features make it ideal for serious runners prioritising speed and agility on uneven terrains. With a combination of comfort, performance, and cutting-edge design, it is highly recommended for trail enthusiasts.

Want to know more? Read my full review below to see why the Adidas Terrex Agravic Speed Ultra is one of the best trail running shoes available today. Let’s dive in!

Adidas Terrex Agravic Speed Ultra review

Price and availability

The Adidas Terrex Agravic Speed Ultra, along with the Adidas Terrex Agravic Speed, was announced in April 2024 and is available to buy now directly from Adidas Terrex UK and Adidas Terrex US for a recommended price of £200/ $220 – AU price and availability TBC.

The non-plated Agravic Speed is less expensive (£150 and $160 in the UK and the US, respectively).

The asking price is steep, but not only a ton of R&D went into developing the shoes, but it’s also a ‘super shoe’ designed for racing and similar road running shoes are sold for much more (e.g. Saucony Endorphin Elite costs £280/ $275).

As you’ve probably noticed, even daily trailers are getting more expensive (e.g. Asics Gel-Nimbus 26 is £180/ $160), so £200/ $220 for top-tier footwear isn’t extreme (sadly).

Specifications

• Best for: off-road racing, especially fast downhill sections
• Tested weight: 290g/ 10.25 oz (men’s UK 10.5/ US 11)
• Drop: 8 mm
• Stack height: 42 mm (heel), 34 mm (forefoot)
• Lug depth: 2.5/3.5mm
• Cushioning: Lightstrike Pro
• Sustainability: contains a minimum of 20% recycled and renewable content

Development and purpose

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The design process that created the Adidas Terrex Agravic Speed Ultra started in May 2021, as it was explained to me and my fellow journalists in Herzogenaurach recently by Jeff Morris, Global Director of Innovation, adidas Outdoor TERREX.

At the time, renowned trail runner Tom Evans wanted to win the Western States 100, which inspired the development of a shoe to help him achieve his goal. After talking to Matt and other Adidas Terrex athletes (e.g. the fab Pablo Villa), the team narrowed their focus to creating a downhill shoe that mitigates the impact force of quick descent.

They also studied hundreds of other races and identified that the fastest runners dominated the downhill sections of races – clearly, a fast downhill shoe, or more like a trail shoe that enabled fast but controlled descents, could provide the upper hand to athletes who wore them on races.

Adidas took inspiration from its road running lineup, too, most notably the Adidas Adizero Adios Pro 3, which included borrowing the Lightstrike Pro foam and tweaking the shape of the shoe’s rocker geometry.

Speaking of iterations, one of the earlier versions of the Agravic Speed Ultra had ‘deceleration ridges’ under the heel. They didn’t work, so they shaved it off on location! Furthermore, the Energy Rods system was modified to better suit off-road conditions, which resulted in the removal of one of the rods.

One thing I found fascinating about the shoes and the concept as a whole is that it’s not just about performance. Sure, the Agravic Speed Ultra is fast, but Adidas Terrex paid attention to the shoes also delivering an experience so that you can feel fast in them. This might sound obvious, but trust me – someone who tested dozens and dozens of running shoes over the years – not all fast shoes feel fast.

Fun fact: ‘Agravic’ is an amalgamation of the words ‘anti’ and ‘gravity’ with a bit of an Adidas flair.

Design and construction

The Agravic Speed Ultra features a number of Adidas technologies, including the Continental Rubber outsole and the Lightstrike Pro foam.

The former can be found on most Adidas road and trail shoes. In the case of the Agravic Speed Ultra, it covers most of the outsole apart from a groove in the middle of the forefoot, possibly in an attempt to reduce the shoes' weight.

Another difference between the Continental outsole here and—let’s say—on the Adidas Adizero Takumi Sen 10 is the presence of lugs. The Agravic Speed Ultra sports a combination of 2.5 mm and 3.5 mm lugs, a bit shorter at the front and longer at the rear.

The Lightstrike Pro needs no introduction; it’s a lightweight foam that focuses on maximum energy return. Here, you get a big wedge of it underfoot, so much so that it would make the shoes ‘illegal’ to wear on World Athletic Approved races, where the maximum stack height limit is 40 mm (the Agravic Speed Ultra has 42 mm under the heel).

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The Energy Rods system has been modified and has a wider profile, running along the perimeter of the forefoot platform – you can see them poking through the foam on the lateral and medial sides of the foam. This platform is indeed expansive and feels both wider and longer than standard running shoes.

I’ll talk about this more below, but one of the most dominant features of the Agravic Speed Ultra is its rocker shape. The curve is intense, although not as sharp as some of the early prototypes of the shoes (see photos above). The rocker is most noticeable under the heels.

Finally, the upper is made of a fine, engineered mesh. It has seamless overlays to provide abrasion resistance and durable protection. Padding is minimal around the ankles, and there are no heel tabs, which makes it somewhat challenging to put on the shoes.

Performance and comfort

I went with my usual Adidas size with the Agravic Speed Ultra, which is half a size over my usual. To my surprise, the shoes felt (and still feel) a bit loose both around the heel and the toebox, which is a strange sensation for an Adidas shoe.

Most running shoe brands can be a bit hit-and-miss when it comes to fit, but in my experience, Adidas generally provides a consistent fit. Not this time! I wish I went half a size under with the shoes.

Once I managed to slip into the shoes, which wasn’t easy due to the thin material and the lack of heel tabs, I almost immediately started rocking back and forth. It almost feels like some foam is missing under the heels. The rocker shape also curls up aggressively at the front.

The forefoot platform is massive and provides a stable foundation for toe-offs. The upper tapers off towards to front, almost funneling your feet into the very front of the shoes upon descends.

The middle section of the foam provides even more stability; it almost feels like there is an oblong ball under your feet. The foam rim around the edge of the upper cradles your foot and helps contain it during fast turns.

How does it feel to run in the Agravic Speed Ultra? Magical. As expected, the shoes really shine during the descends. I was slightly apprehensive at first, not letting myself go hard, but after a few strides, I realised I was in good hands and really leaned into it.

Once you start speeding downhill, all the puzzle pieces fall into place: the heel construction, the forefoot platform, the shape of the upper, and the modified Energy Rods all work together to help you gather and maintain speed on the decline.

Of course, most of the features help you move forward even when the terrain isn’t on the decline. The lugs, in particular, helped me avoid faceplanting on one of my runs when I mistakenly tried to hold onto a slippery log to avoid a large puddle.

I also appreciated the foam cradle, which helped me keep my stride in check on uneven terrain. If only the shoes were my size so I could enjoy them even more! But even so, the Agravic Speed Ultra has been a lot of fun to run in already.

Verdict

The Adidas Terrex Agravic Speed Ultra is a very good trail running shoe. It’s tailor-made for fast long-distance races, and I hope it’ll have the same effect as the Nike Vaporfly did back in the day, namely enticing more beginners to try longer distances.

I am not suggesting you should sign up for the UTMB or the Barkley Marathons (not like you can, anyway). But there aren’t enough people enjoying trail running, which is sad, as it’s a very different environment from road races – in the best possible way.

What I like the most about the Agravic Speed Ultra is the innovation and House of Adi’s effort to advance footwear design. Sure, stuff like the Adidas Adizero Adios Pro Evo 1 is more novelty at this point, and the Adidas Adizero Prime X 2 Strung is more a revolution than an evolution, but the company is definitely trying to make a difference.

If you’re into trail racing, especially longer distances, and like running fast, the Agravic Speed Ultra is a no-brainer purchase. It feels like a niche product (i.e. fast downhill trail racer), but in reality, this feature allows you to become the fastest version of yourself overall. Highly recommended.

Also consider

Salomon Speedcross 6: Known for excellent traction, particularly on muddy trails.

Hoka Speedgoat 6: Offers maximum cushioning and a comfortable fit for long-distance runs.

Brooks Cascadia 18: Provides a balance of cushioning and support for rough terrain.

Inov-8 Roclite G 275 v2: Known for its durable grip and lightweight design.