ON Cloudflyer 4 Introduction

Cloudflyer debuted in 2017 as a lightweight low stability shoe and has changed quite a bit since, moving more “stability” and less “lightweight.” The shoe has presented with different drop heights —9 to 7 and now to 11 mm.—and increased in weight by 1.7 oz. from the first Cloudflyer.

More firm side panels and a wider sole now enhance its moderate stability, and the upper is now more cushioned for increased comfort.

On is trying some fun and some not-as-helpful innovations in the upper (see upper section).

What has not changed is that Cloudflyer is an expensive shoe, going from $160 USD up to just shy of $170 USD. The increased ability to customize the forefoot fit due to unique lacing technology and cushioned-responsive sole may make the price worth it for some users.

Cloudflyer is marketed to offer “supreme cushioning plus premium comfort” and their “plushest ever tongue,” which does not match my experience as I tested these side by side with the brand’s Cloudgo. Cloudgo was released two months before the Cloudflyer 4 with a higher cushion; see the “upper” and “sole” sections below for a detailed comparison.

Cloudflyer competes with Brooks Ravenna in responsive stability; Lululemon Blissfeel is similar but quicker into toe-off.

Cloudflyer is only a fraction lighter than the brand’s Cloudace stability shoe but has a significantly lighter-feeling ride along with thicker walls on the cloud pods underfoot.

ON Cloudflyer 4 First Impressions

The anticipation of unboxing new running shoes can’t be beat for our particular brand of people, and the current industry hotshot, On, brings no exception. On Cloudflyer 4 looked sleek, stylish, and techy. I didn’t even realize all of the particularities until examining the shoe in more detail a few runs later.

Slipping them on I noted the roomy fit and smooth roll forward. It fits true to size.

Early runs with both Cloudflyer and Cloudgo proved Cloudflyer better suited for faster running, and Cloudgo for supreme comfort.

The unique lacing system allows for a customized forefoot fit, and the midfoot can be pulled in by the laces. I need to use the top holes to get a better, yet still not ideal, heel lock.

After 14 miles on Cloudflyer in three days I had to take a break because the medial ankle piece next to the laces was cutting into my skin. The irritation was minimized by wearing higher (for protection), thicker (for better fit) socks and not using the top holes.

In contrast, Cloudgo has an excellent heel fit (with no use of top holes) and a soft pad around the ankle.

Medium-width heels may fit very nicely in Cloudflyer but could potentially still be irritated by the high collar with stiff aspects.

ON Cloudflyer 4 Upper

A re-engineered upper brings more padding and structure (and weight) to this version of Cloudflyer, with plastic overlays protecting the tip, reinforcing the lace holes, and framing side panels to aid a locked-in feel.

Innovation shines as the tongue slides under side overlays that extend 2-3 cm. beyond their attachment to the rest of the upper. The tongue then merges with the toe box mesh under the overlay.

Shoe strings first run through the bottom “regular” holes and up through two loops in the toe box before lacing the rest of the ties. Together with the flexible mesh this allows for the most custom fit at the ball that I’ve come across!

After multiple runs I thought the shoe was narrow in the toe and medium through the rest, but when I loosened the strings through those forward loops, I was reminded that it is medium throughout but adjustable—also available in wide width.

Towards the back, a higher heel collar is meant to provide a more-secure feel—but will potentially nick against some runners’ lateral and medial malleoli (the bony bumps on the sides of the ankles) as it does for me.

The heel is capped by a moderately strong external heel counter to guide the foot plant forward.

The front of the lateral ankle opening also cut my skin as I tied the laces through the very top holes to better lock in my heel, which pressed the rigid corner into my front ankle.

On promotes Cloudflyer’s tongue as their “plushest ever.” In reality it is a pretty standard tongue only a hair thicker than Cloudgo’s, with Cloudgo’s being wider to cushion more of the foot.

To avoid discomfort I unlaced the top laces and got used to a less-than-ideal heel fit. This made long laces even longer, and they would sometimes hit my other leg while running through tied and double-knotted.

Cloudgo has a secure heel fit (without using top laces), so I know On knows how to get it done; hopefully, they’ll change this going forward.

Cloudflyer fits true to size for length and medium for width.

It fits the same at the ball of the foot when matched up with Cloudgo but with more “give” due to the mesh and the construction of the lace described above. Cloudflyer then narrows more than Cloudgo moving to the tip.

ON Cloudflyer 4 Sole Unit

On’s signature cloud pods in the sole are made from the brand’s Helion™ superfoam, which combines rigid and flexible elements, and Zero-gravity foam to cut out extra weight. The section under the heel is more dense and firm for greater stability for heel strikers and a quicker transition for all wearers.

Upon landing, the pods compress against a thermoplastic polymer plate called a Speedboard® located near the top of the midsole. The pods pop back to provide a uniquely buoyant ride with stiffness and responsiveness due to the board.

Like in the Cloudmonster, the Speedboard® is custom designed with a surfer’s experience in the background to give just the right ride to each runner.

As with most On shoes, the arch height is medium to allow more runners access to the shoe. Custom inserts are a great option for those who need higher arch support.

Cloudflyer is built with a wide base which works together with the Speedboard® to create a stable ride. The width is about the same as found in the Cloudgo but slightly more narrow towards the tip; drop is 11 mm. heel down to forefoot.

Rubber patches cover much of the forefoot, the back heel pods, and late lateral midfoot pod to protect these higher abrasion areas and provide grip together with ridges cut into the foam of the exposed Cloud pods.

ON Cloudflyer 4 Conclusions

Cloudflyer is a versatile shoe in both fit and function.

The medium width can be dialed in by the laces for the forefoot and midfoot, but the heel is simply going to be too loose for some runners; others will welcome the heel space that they need.

The combination of cloud pod cushion and responsive Speedboard® make this a good choice for runners who want one shoe for both longer interval training and medium-distance runs.

Long laces, a high collar, and rough corners around the ankle opening will bother some runners, but the cushioned yet responsive ride through a moderately quick transition onto toes may be exactly what you are looking for!