My first thought when seeing the Adidas Terrex Speed Ultra shoes was ‘they look stylish!’. These are shoes you can proudly wear around town when you’re not out running. I tested the ‘core black/matte silver/solar red’ version, which is a beautiful colour combination, and other colour schemes aren’t bad looking either. They are comfortable for walking and make excellent street wear shoes. However, the main question is not how fashionable they are, but how do they fare as trail shoes, and on running long distances? Are they up to the ‘racing’ printed on their side?
The shoe design appears highly engineered. It includes a number of innovations from Adidas’ toolkit, and was developed with elite ultrarunner Tom Evans’s input. Tom Evans notably finished third at UTMB in 2022 and won many other international races (the list being too long to be included here), using shoes from the Adidas Terrex range.
The other immediate notable feature besides their good look is their light weight, which I could confirm on my kitchen scale. They are lighter than many other racing shoes from other brands within the same ‘light trail racing’ category. Adidas obviously had to compromise on the amount of materials used to get that to that result, therefore the shoes feel optimised about that. They are not overly generous on bounce, cushioning, and protection, and rather provide just the right amount of each.
Like many other Adidas shoes (designed for trail or road), the outsole is the product of a collaboration with tyre company Continental. The Continental rubber provides excellent traction, without feeling sticky to the ground. The lug geometry is shallow (with 2.5mm lugs) and with a rather dense treading pattern, reminding me more of a tyre (this is Continental, after all) than of a typical trail shoe. This is not an aggressive lug pattern suggesting that grip will be on the weaker side on muddy trails.
The midsole is made of two layers, with Adidas’ extra cushioned and soft Boost foam under, spanning the midsole from the heel to the middle of the foot, and Adidas’s denser Lightstrike foam above, covering the entire surface of the shoe and providing stiffness, bounce and energy return with less midsole volume. The overall midsole is stabilised within with a rigid part (Adidas’ Torsion system), however the shoe remains flexible. The midsole stack at 18/26mm (8mm drop) is on the thinner side, and the shoes feel close to the ground when running. The result is a comfortable and reactive ride, just lacking bounce in the forefoot to my taste, that I would have found useful when running uphill.
The upper is made of a light, flexible, meshed (therefore breathable) plastic material, with additional coating at the front of the shoes covering the holes in that mesh structure to prevent humidity and dust from entering the shoe when hitting the ground or running through grass. The overall shoe and the toe box are on the narrow side and overall ran true to size. The tongue is minimalistic, with its sides sewn to the upper with elastic fabric, providing a sock-like fit. There is a little padding under the tongue and at the heel for comfort and lock, again Adidas providing just the minimal amount of material to keep the overall shoe weight down. For the same reason there is no heel stiffener. This design makes the overall upper fully flexible and collapsible, without stretching to fit the foot however. It worked well for me overall, I did not experience any ‘hot spot’ or friction, the heel lock was effective and the fit was tight yet comfortable.
These shoes fall in the category of ‘you could forget you’re wearing them’. That is, until the laces keep coming untied. It happened to me several times, and it felt like a let-down by Adidas given the amount of engineering that had been included in other parts of the shoes, and given how easy it is to fix this issue by changing the laces. I went on using more sophisticated lacing knots – the laces’ length being on the longer side was helpful for that purpose.
I tested the shoes on a variety of terrain conditions over many outings of up to 3 hours each. Although the shoes felt stiff at first, they got more comfortable over time, suggesting longer outings and venturing into ultra-distances is unlikely to be an issue. The ‘ultra’ in their name is deserved.
My first outings were in and around London, on hilly, grassed and forested trails. As is often the case we had a fair amount of rain, and the trails were wet and muddy. As I had guessed after seeing the outsole for the first time, the shoes didn’t perform well in these conditions. The grip was weak, and perhaps due the treading geometry on the outsole, the shoes accumulated mud underneath quickly, turning a ‘shoe on mud’ run into a ‘mud on mud’ sliding exercise. Running hills hard then was out of the question. In addition, the gap within the outsole where the torsion system can be seen trapped mud and other debris. Although that lack of grip can be managed during training runs by being slower and careful, it is obviously problematic when speeding up and racing.
Fortunately, trails dried up around London allowing more testing, and I also had the chance to try the shoes during a trip to Florida – where the lack of hills to test the shoes is compensated by many hard-packed trails surrounded by lush vegetation, and at times on sandy ground. The good news was these shoes were great on such hard-pack, drier trails. They felt light, fast and nimble, and jumping around obstacles was fun. The shoes felt precise where foot landing accuracy was needed on technical paths with roots and rocks. I also noted their tight (yet comfortable) fit did not easily let debris in. They performed well on rocky ground, the outsole providing excellent traction, even on sand. Despite the midsole stack being thin and the absence of a rock plate I did not feel discomfort when running over pebbles and other uneven surfaces. My surprise was how well they also fared on road, bringing a fast and comfortable ride. They were reactive shoes with just enough cushioning and bounce. Road running shares many characteristics with hard packed trails, it was logical these shoes would perform well on both.
Overall the Adidas Terrex Speed Ultras will be a useful addition to my summer racing toolkit once the trails dry up. They delivered well on mixed terrain, which is often the case in trail races or just for a home-to-road-to-trail run. And they unlike many other trail shoes in the market, they are good looking ones.
Review by Julien Cazorla
