Topo Ultrafly 6 review

The Topo Ultrafly 6 is a solid choice for runners who:

• Need an anatomical fit with plenty of room for natural toe splay without sacrificing a secure midfoot lockdown.
• Prefer a firm, stable ride over the ultra-soft feel found in many modern daily trainers.
• Land on the midfoot or forefoot and want a stability shoe with a moderate heel-to-toe drop.
• Prioritise long-lasting durability and reliable support for everyday training.

Heavier runners, or anyone seeking maximum shock absorption, should probably skip the Ultrafly 6, as it simply doesn't offer enough cushioning. Instead, we recommend the Saucony Hurricane 25 or the Nike Structure Plus.

We also believe that neutral runners should 100% skip this shoe. The Topo Cyclone 3 or Topo Spectre 2 both deliver a noticeably more lively and fun ride thanks to their Pebax midsole.

The Topo Athletic Ultrafly 6 delivers a slight increase in shock absorption over the Ultrafly 5.

However, it still falls short of standing out in this area. It posted just 114 SA in the heel and 102 SA in the forefoot, so runners seeking maximum impact protection should pick another option.

We found that Topo Athletic sticks with ZipFoam in the Ultrafly 6, and we see this decision as a disappointing choice. This basic EVA foam feels lifeless underfoot and still delivers underwhelming energy return, reaching just 48.3% in the heel and 52.7% in the forefoot.

Brands can always claim that each update improves responsiveness, but our lab data sometimes tell a very different story. Ultimately, it's up to you to decide whether you trust the data or the marketing claims...

Topo keeps the Ultrafly 6 at a moderate heel stack of 33.0 mm. While that may seem low by today's standards, it's 2.8 mm taller than the Ultrafly 5.

We think this gradual increase is a sensible approach, allowing Topo to steadily improve cushioning without dramatically changing the shoe's character.

The forefoot measured 26.4 mm, placing it almost exactly at the current lab average at the time of this review. This also helps explain the shock absorption values we recorded earlier.

As is often the case with Topo Athletic shoes in our lab, the Ultrafly 6 delivered a slightly higher drop than the brand's stated value. Instead of 5 mm, we measured 6.6 mm. Even so, this remains a moderate drop that keeps the shoe especially appealing for midfoot and forefoot strikers.

The Topo Ultrafly 6 features a new dual-density midsole designed to enhance stability, an approach widely adopted across the running shoe market.

We pressed our Asker C durometer into the main layer of foam and measured a firmness of 39.1 AC, which more or less matches the firm ride we experienced during testing. In fact, the shoe felt maybe a bit firmer underfoot, and there's a good reason for that, as you'll see next...

A second foam layer extends from the heel to the midfoot acting as a medial post to improve landing stability. And when we say firmer, we mean it. Our durometer measured this layer at a substantial 53.7 AC!

Like most Topo Athletic running shoes, the Ultrafly 6 features a classic rocker that never feels intrusive or artificial. The profile remains mostly flat, with just enough curvature to complement the natural shape of the foot and provide a subtle amount of guidance through each stride.

Like every Topo Athletic running shoe we've tested, the Ultrafly 6 offers generous room for natural toe splay. Even so, it avoids feeling sloppy and can still provide a comfortable fit for some runners with narrow feet, which is critical in a stability shoe.

That's because Topo typically keeps the width at the widest part of the forefoot close to the average rather than making it excessively wide. The Ultrafly 6 follows the same formula, measuring 96.7 mm in this area.

Unlike most stability shoes, the Ultrafly 6 features an anatomical toebox that closely follows the natural shape of the human foot.

This design makes it an excellent choice for runners who hate cramped toes, particularly those with a square-shaped foot.

Again, Topo stays true to its usual design philosophy with the Ultrafly 6.

The generous toebox height is another hallmark of the brand. We confirmed this with a roomy measurement of 30.9 mm.

One of the riskier aspects of the Ultrafly 5 was the large amount of exposed midsole foam.

With the Ultrafly 6, Topo has taken a step back by extending the rubber coverage, helping protect the foam from premature wear. We think it's a smart update for a stability shoe, as some overpronators often wear through outsoles quite fast.

The Topo Ultrafly 6 is slightly stiffer than its predecessor (11.0N) due to the added stack height and increased outsole coverage. Even so, it remains a flexible shoe, something many runners will appreciate, especially those who also use the Ultrafly series for walking or everyday casual wear.

Despite featuring a bulkier midsole and more outsole rubber, the Ultrafly 6 weighs exactly the same as the Ultrafly 5 at 9.6 oz (272g). That's excellent news, as we expected a weight increase, but the new mesh upper appears to have offset those additions.

On the other hand, if Topo eventually switches this shoe to a supercritical EVA foam, we believe it could become 10% to 15% lighter while also delivering a far more energetic ride. Go for it, guys!

Topo Athletic has completely redesigned the way the Ultrafly 6 delivers stability. The new setup features a medial post that extends farther around the heel, complemented by increased torsional rigidity and a wider heel platform than its predecessor.

The increase in torsional rigidity is substantial. The Ultrafly 6 is 47% stiffer than the Ultrafly 5, delivering greater support and a more planted ride. However, runners who prefer a highly-flexible shoe in every direction may dislike this change.

Most brands would opt for a rigid heel counter here, one we'd likely rate at 4/5 or even 5/5. Instead, Topo sticks with a much more forgiving (though less stable) design that stays out of the way and feels exceptionally comfortable, earning just a 2/5 in our assessment.

Another area where Topo stays true to its design philosophy is the platform geometry.

Because the Ultrafly 6 doesn't rely on an ultra-high stack, it can retain the more traditional dimensions of a classic daily trainer. We measured the forefoot platform at just 114.6 mm.

The heel is now 4.1 mm wider than before, reaching 91.0 mm. While that isn't a dramatic increase, it adds a welcome dose of rearfoot stability without sacrificing the agile feel that has long defined the Ultrafly series.

The new lightweight engineered mesh upper allowed Topo to keep the shoe at the same weight, but that came at the expense of durability.

After attacking the toebox with our Dremel, the Ultrafly 6 earned the lowest possible score of 1/5, and only because our scale doesn't go any lower.

Fortunately, the Ultrafly 6 makes up for it by earning a perfect 5/5 in our heel padding durability test. That's a welcome result, and likely the more important one for many runners.

More importantly, the outsole proved exceptionally durable. Our Dremel removed just 0.6 mm of rubber, and when combined with the increased outsole coverage we observed earlier, the Ultrafly 6 stands out as an outstanding choice for runners who prioritise long-term outsole durability.

We reached for our callipers once again to measure the outsole rubber thickness, and the result was another win for durability-minded runners at 3.0 mm.

Combined with its outstanding abrasion resistance, this outsole is clearly built for the long haul.

The Ortholite insole measures 4.4 mm thick, placing it right in line with what we typically see in modern running shoes.

You can easily remove it, which is great because the generous toebox height makes this shoe an excellent candidate for third-party or custom orthotics.

Our freezer test showed that the midsole became just 12% firmer after spending 20 minutes in sub-zero conditions. That's a positive result for a standard EVA-based foam.

We hoped Topo would finally add reflective elements after leaving them out on the Ultrafly 5. Unfortunately, the Ultrafly 6 still comes without them.

Topo rarely strays from traditional punched eyelets. We also spotted the brand's signature dual tongue loops, which do a good job of holding the tongue securely in place throughout the run.

The tongue packs 8.0 mm of padding, providing excellent protection against lace pressure while delivering a plush and reassuring step-in feel for everyday use.

The dual tongue loops become especially important here because the Ultrafly 6 doesn't feature a gusseted tongue.

The heel design clearly identifies this as the sixth-generation Ultrafly, and as with previous versions, it comes without a heel pull tab.

Topo has kept the Ultrafly 6 at the same price, and that almost feels like a victory in today's market.

We think raising the MSRP would have been a mistake, as competition is stronger than ever and offering solid value is one of the few advantages this model simply can't afford to lose.