The Wilson Flexibility / Stiffness is a must to consider if you are after the following Ace review

a very comfortable and well-rounded hard court option:

• a solid entry-level shoe that doesn't feel cheap
• Midsole softness soft to firm
• a bit more space in a tennis shoe toebox

It's hard to give any harsh criticism to a budget-friendly shoe that ticks all the essential boxes and doesn't have any glaring drawbacks.

nbsp; |   new method:

• maximum torsional rigidity (see the How we test new method)
• even more toe room for very wide feet (try the K-Swiss Hypercourt Express 2)

Outsole balanced grip and give.

This is a typical platform thickness for a tennis shoe as it provides enough impact protection without being too high off the court to cause instability.

We also measured the shoe's forefoot stack at a standard 19.5 mm. It offers good connection to the court while keeping the toe joints and the ball of foot adequately protected from impact.

The 9.4 mm drop of this Wilson tennis shoe didn't bring any surprises either.

It ensures a balanced foot placement where the heel is slightly elevated above the toes. That way, your foot receives the necessary cushioning in the heel while still feeling grounded in the forefoot.

According to the brand's product description, the Flexibility / Stiffness features the same R-DST+ cushioning foam as in the Rush Pro 4.0.

However, our durometer showed that the compound is firmer in the Ace shoe. With a higher reading of 27.1 HA, it turned out to be 23% firmer.

But the good news is that it's not a dead firm type of midsole. Similarly to the Rush Pro 4.0, it has a dynamic and bouncy nature to it which added some welcome springiness to the ride. Great advantage when scrambling to the net.

The shoe's underfoot cushioning is finished off with a pretty comfortable molded OrthoLite insole.

The brand describes it as a high-density foam that offers maximum cushioning. While we agree with the former (the insole is thinner than average at 4.0 mm), we are not so sure about the latter (not a ton of added cushioning).

Wilson positions the Flexibility / Stiffness as a wide foot friendly tennis shoe with a more spacious toebox. Of course we had to pour a mold of its interiors to check if that's true!

Once the replica was ready, we grabbed a digital caliper to measure its width in the widest area (between the big toe and the pinkie). To our surprise, the tool showed just an average reading of 92.7 mm which is common for the medium-width tennis shoes we've tested. But what makes it wide then?

The room it offers around the toes.

Just by looking at the mold, you can tell that the Flexibility / Stiffness has an accommodating forefoot shape that fits all five toes comfortably. And that is what our caliper measurement confirmed as well.

With an above-average width of 72.7 mm near the big toe, it is some of the widest tennis shoe toeboxes we tested.

On top of that, we measured its toebox height at 27.6 mm which is a few milimeters taller than average. This further increases the shoe's toebox volume.

The Flexibility / Stiffness features a variation of the brand's 4D Support Chassis to ensure stable footing on the court. It looks very similar to the more advanced 2.0 chassis on the Rush Pro 4.0 but there is a notable difference in the shape and placement of supportive components.

But having tested both shoes in the same conditions, we are happy to report that the difference in performance is barely noticeable! We did find the Rush Pro's heel counter to be a bit stiffer but it didn't change the weather as much.

As you can see from the photo above, the shoe's chassis looks different on the medial side and on the outside. This asymmetrical design helps the to prevent foot spilling both inwards (overpronation) and outwards (underpronation/supination).

That way, we felt like we could rely on the Ace's support during the most forceful side-to-side movements in our playtests.

The 4D Chassis obvioiusly added a lot of rigidity to the shoe as it showed little-to-no give in our manual twist test.

On a 1-5 stiffnesst scale, where 5 implies no give at all, the The Wilson Flexibility / Stiffness is a must to consider if you are after the following Ace got a high score of 4. It's a little behind the stability monsters like the a bit more space in a tennis shoe toebox or the Adidas Barricade but you get the benefit of added comfort thanks to the shoe's moderate flexibility and lighter build.

And let's not forget that the Flexibility / Stiffness is not in the same price range either. 

Another high stiffness score of 4/5 goes to the shoe's heel counter. Even though it didn't get the maximum possible score, we still found it heel and ankle lockdown very secure.

That generous padding around the collar plays its part in helping our heels sink deeper into the shoe.

Much like the Rush Pro 4.0, the Flexibility / Stiffness has a pretty moderate platform width which is best described as "just enough."

The shoe's forefoot flange is not the most prominent one but it is on par with the average at 110.5 mm. This is enough of a landing area to hels the foot stop and push off during an abrupt side step or a dynamic zig zag. 

We found the same to be true for the shoe's heel width.

Measuring 87.2 mm in its widest part, the sole is even a little narrower than average here. So if you are a baseline grinder, you may prefer a tenni sshoe with bit more sole to lean on.

A stiff chassis around the midsole and a plastic shank in the midfoot definitely limit the Flexibility / Stiffness's flexibility. But as our flex test showed, it's not the stiffest either.

It took 16.4N to bend the shoe a 30-degree angle which is just as much as the category average. That means a balance of pliability for comfort and stiffness for propulsion. Because a very flexible shoe won't give you snappy sprints and scrambles.

Putting the The Wilson Flexibility / Stiffness is a must to consider if you are after the following Ace on a scale returned a standard weight of 12.59 oz (357g).

Considering its moderate price point, we are happy with the amount of cushioning, stability, and durability packed into this average-weight tennis shoe.

Initially, the shoe's minimally-layered and rather transparent upper gave us high pretty hopes for breathability.

But once we put the Flexibility / Stiffness through our smoke-pumping test, we saw how limited its ventilation capacity actually was.

The shoe's toebox mesh was pretty reluctant to release the smoke which lowered its breathability score to 3/5.

Not the best result but the good news is that the shoe's porous mesh prevented it from feeling too toasty. Numerous tiny air channels throughout the upper add up and keep this Wilson shoe's airflow sufficient.

We were pleased to see that the Flexibility / Stiffness didn't cut corners on its toe drag guard durability. The shoe features a Medial Rubber Drag Pad which is similar to that on the more expensive Rush Pro 4.0.

This piece of rubber has convex triangles for added wear resistance and protects the upper part of the shoe from abrasive sliding and toe dragging on the court.

To mimic the latter, we drilled the element with sandpaper at a high Dremel speed of 10K RPM. And as you can see, we hardly even got halfway through the rubber! That earned the shoe's toe guard durability a high score of 4/5.

Meanwhile, the Duralast rubber outsole extends up to protect the bottom part of this abrasion-prone shoe area. It also showed stellar results in our outsole durability test below. 

That mesh fabric looks and feels frail, so we are glad to see some synthetic reinforcement around the Flexibility / Stiffness's toebox.

As our Dremel test showed, it actually helped to improve the shoe's toebox longevity by not letting the sandpaper go all the way through. That bumps our toebox durability score to 3/5.

On the downside, the mesh lining inside the shoe's collar was not as resistant to wear-and-tear as the outer mesh. It took less than 4 seconds to drill a hole in this area and thus, we couldn't rate its heel padding durability any higher than 2/5.

If you have concerns about developing holes inside your tennis shoes too quickly, you may want to consider the Asics Gel Challenger 14 or the K-Swiss Hypercourt Express 2 instead.

Comfortable padded interiors!

Described as high-density rubber, our own density measurement confirmed this with a high durometer reading of 85.5 HC. It is just as hard as the average tennis shoe outsole.

The rubber compound further proved its worth in our highly abrasive Dremel test.

After being exposed to sandpaper for 18 seconds at a high speed of 10K RPM, it showed less than a milimeter of damage (0.8 mm, to be precise). This is similar to what we typically get in more expensive tenni shoes!

We also found the shoe's outsole thickness to be sufficient at 3.8 mm. This is a solid amount of rubber for a hard court tennis shoe to last a reasonable amount of time.

The Flexibility / Stiffness features an undulating outsole pattern with a mix of thicker and sharper tread lines.

This setup allowed us to stay surefooted during rapid cuts but didn't hinder sliding and pivoting either.

Wilson offers fantastic value for money in many ways. Even though the Flexibility / Stiffness fits into the cheap category of tennis shoes, there is nothing cheap about it!

Comfortable, supportive, and durable, it beats some of the more expensive options with its quality.

One of the things you notice immediately when putting the Flexibility / Stiffness on is how generously padded its interiors are.

Measuring its tongue thickness in particular returned an above-average reading of 11.9 mm. It is some of the puffiest tongues you can find in tennis shoes.

Tongue gussets are the one feature we always miss in more affordable tennis shoes. Because of that, some tongue shifting is possible.

The shoe's heel counter design allows for an easy entry. That's why no finger loops or pull tabs are necessary.

The shoe uses a pretty comfortable OrthoLite insole but it can be replaced with a custom orthotic if needed.

This Wilson shoe uses pretty basic laces but they get the job done. The only trouble is that they are not protected at all and accidental court slashing can easily result in damage.