Adidas Adizero Ubersonic 4.1 review

As one of Adidas' leading tennis shoe series, we believe that the Ubersonic 4.1 is going to match well with players who:

• want a speed-oriented shoe for all-court play
• enjoy a snug fit of a one-piece bootie-style upper
• like the idea of a sustainable tennis shoe that comes with recycled materials

We foresee that players with wider feet are going to struggle quite a bit with the Adidas Ubersonic 4.1. Not only while wearing it but even while putting it on! In our opinion, these folks will be much better off with the New Balance FuelCell 996 v5.

And if you despise the feeling of wet socks on a summer day, we recommend a better-ventilated ASICS Solution Speed FF 2 or the Nike Vapour Pro.

When we first saw the transparent paper-thin mesh on the Ubersonic 4.1, we thought its ventilation capacity would blow our socks off! And yet, and yet... On the court and in the lab, this material left us wishing for more.

Equipped with a smoke-pumping machine, we filled the shoe's upper with smoke and observed the way it passed through the fabric. Interestingly enough, the smoke was coming from all over the shoe's upper and not only through the toebox or the tongue area (as is often the case).

We also hovered the shoe's half-cut upper over a bright light to check for any dominant ventilation holes. We didn't find any but the semi-transparent material explained the evenly distributed breathability of this shoe.

Curious to investigate this unique fabric, we looked at it up close through our microscope.

Its thin yarns are made of recycled materials and are very densely intertwined, forming a texture that is much sturdier than it looks. But unfortunately not as breathable as we had hoped.

These days, there is still a bias that sustainably made products are of inferior quality to the common ones. But Adidas turns that around with its "high-performance yarn" which is made of Parley Ocean Plastic and recycled polyester. In addition, there is a protective Adituff overlay in the most abrasive area of the toebox (also recycled).

Knowing how little effort it takes to tear a hole in a tennis shoe upper, we grabbed our trusted Dremel to test the limits of this Adidas shoe. With the speed set to 5K RPM, we applied the tool's sandpaper tip to the toebox at a consistent 3.2N pressure for 12 seconds.

Despite the visible damage that our Dremel left on the toebox, the tool failed to critically harm the upper material! The Adituff toe drag guard served its part very well, earning the Ubersonic 4.1 the highest score for toebox durability: 5 out of 5!

Looks like this Adidas shoe is not only reinforced on the outside but also quite abrasion-resistant on the inside!

Its inner mesh lining didn't look anything special but when we applied our Dremel to it for 4 seconds, it revealed a pretty durable nature.

The scuffing on the heel lining turned out to be merely cosmetic and didn't allow the tool to drill through the padding. On a 1-5 scale, where 5 is the most durable, we gave it a solid 4.

The Adidas Ubersonic 4.1 features a surprisingly soft, even tacky rubber. Based on our durometer measurements, it comes in at 73.4 HC which is way softer than the average tennis shoe rubber (by 17%).

Although it gives the benefit of grip, it makes us concerned about durability.

Turning back to our Dremel, we went full force on the shoe's outsole. With the speed set as high as 10K RPM, we held the sandpaper tip against the rubber for 22 seconds. We also applied the same pressure (3.2N) for consistency.

Luckily, the result wasn't as bad as we expected given the softness of rubber. But it still proved to be more prone to abrasion than most other tennis shoes.

As our tread gauge showed, the dent in the outsole was 1.0 mm deep. That's a bit deeper than what we normally see. And there is no durability warranty either which is a bit surprising given the price of this Adidas shoe.

Measuring the shoe's outsole thickness with a durometer, we got a thicker-than-average reading of 5.0 mm.

No wonder Adidas threw an extra millimeter of rubber into the Ubersonic's outsole. It definitely needs that for prolonged life.

Given its speed-oriented design, the Ubersonic 4.1 doesn't feel clumpy or heavy on foot at all! We were able to move around the court effortlessly, never feeling halted or dragged down.

It's not the lightest tennis shoe in our lab either but it tips the scale at a lower-than-average weight of 12.3 oz (349g). If you want an even lighter option, try the ASICS Solution Speed FF 2.

Adidas managed to pack more cushioning into the shoe's heel without compromising the weight! Our hard landings felt very comfortable and supported in the Ubersonic 4.1.

The secret to that is 29.7 mm of midsole thickness under the heel. It's not more cushioned than the average but quite tall for a speed-oriented shoe.

The forefoot, on the other hand, comes in at 17.5 mm. This stack height is on the lower end of the spectrum, bringing the balls of our feet much closer to the court and making us more in control of the movements.

What we found surprising in this tennis shoe is its pretty drastic difference between the heel and forefoot stack heights. At 12.2 mm, it is taller than the average 10 mm and also taller than the typical 8-9 mm of speed-oriented shoes.

But this was not a deal-breaker for us by any means. In fact, it sort of encouraged our feet to lean forward throughout the game.

But if you expect a more intimate connection with the ground, try the New Balance FuelCell 996 v5.

Carried over from the brand's running shoes, the Lightstrike foam creates a wonderful experience in the Ubersonic 4.1! It is a one-density, full-length component that felt moderately plush underfoot while giving us a very welcome pop and bounce.

Pressing a durometer against the foam returned 21.6 HA which is a whopping 40% softer than the average across tennis shoes! But there is no need to worry about mushiness as the shoe comes with a stabilizing shank under the arch (more on that below).

On top of the Lightstrike, there is a well-padded insole. Our caliper showed 6.7 mm of thickness in its heel area which is slightly cushier than average.

Because it's not an Adidas Barricade shoe, we didn't expect much stability from the Ubersonic 4.1. But, apparently, Adidas decided that a lightweight shoe can have some stability in its life too!

The primary stabilizing element of the Ubersonic 4.1 is a stiff shank placed under the arch of the foot. It doesn't protrude outside or extend up on the sides but it did all the invisible work to prevent our ankles from rolling over in this Adidas shoe.

On a stiffness scale from 1 to 5, where 5 is the stiffest, we gave it a nearly maximum 4 out of 5.

Even though the shoe's platform proved to be pretty stable, we are not sure if players with severe overpronation will find its heel counter reassuring enough.

Pushing and squeezing it, we found the Ubersonic's heel counter more pliable than the average tennis shoe. We rated it with a below-average stiffness score of 3 out of 5. So, you may prefer the Barricade 13 after all if you aim for the highest level of stability.

A crucial aspect of every tennis shoe's stability is its amply wide platform and a lateral outrigger in particular. The Ubersonic 4.1 seems to be doing it all right as it made us feel so incredibly supported on forceful lateral movements.

Measuring the widest area of its forefoot, we got 110.9 mm. It is not wider than the average tennis shoe but certainly enough for our liking.

The same goes for the shoe's heel platform. Showing 88.4 mm in its widest part, the heel is just as wide as we would expect from a tennis shoe.

Players who prefer a more flexible tennis shoe that lets the foot bend naturally will appreciate the Ubersonic 4.1 a lot! Its shank only covers the midfoot and doesn't go under the forefoot which creates a nice breaking point for the shoe to flex as much as you need.

To back up our subjective experience with data, we conducted our in-house flexibility test. Once the shoe was fixed to the table, we bent it to a 90-degree angle and measured the amount of force with a force gauge. Turns out that this Adidas shoe only takes 20.6N!  That's 60% less than it takes a typical tennis shoe!

But if you do enjoy the propulsion that a stiff shank creates and find it beneficial for speed, try the New Balance FuelCell 996 v5 (120% stiffer than the Ubersonic!).

Even though we found that the Adidas Ubersonic 4.1 has a tackier kind of rubber, it can still slide quite well. We believe that it's due to the combination of sharper and smoother treading on the outsole.

The good old herringbone pattern accommodated our starts and stops blissfully.

If you are a medium-width footer like us who prefers a close-fitting tennis shoe, you will be happy with the Ubersonic 4.1.

But don't worry, it doesn't feel constricting but rather pleasantly snug. Measuring the widest part of the shoe's toebox, we got 101.0 mm on our caliper. That's a standard measurement across tennis shoes in a men's US size 9.

This Adidas shoe didn't put pressure on our toes either. There is a slight toebox tapering but no pinching or squeezing.

Using our caliper, we got 78.0 mm at the big toe mark. That's just the same as the average.

Given the shoe's sock-like bootie design, its tongue is fully integrated into the upper. This kind of setup is a love-or-hate one, really. If you tend to struggle with narrow collars when getting the shoe on, it's better to stay away from this one.

But on the bright side, heel slippage is non-existent here.

The lockdown on the Adidas Ubersonic 4.1 is quite secure as is. But with the extra eyelet, you have the option to cinch it up even tighter by tying a runner's knot.

Adidas went for a more sock-like feel in the Ubersonic 4.1. So, you won't find much plushness and padding in its interiors.

For example, the shoe's tongue comes in at 6.1 mm which is slightly thinner than average. Granted, we never experienced pressure or bites from the laces.

The Ubersonic features a much-needed fabric loop that aids in getting the shoe on. It definitely minimized our struggles with the narrow collar.

If you wish to take the Ubersonic 4.1 to the next level of comfort and add a custom insert, it is easy to do with the removable insole.