November 01, 2023
Review by Bryan, The Chubby Runner

Moving forward after the hype around the amazing upgrade to the Cloudsurfer 7, On has now made changes to another legendary shoe in their arsenal: The new and improved (personal opinion) On Cloudflow 4.

At first glance

Everyone knows and loves the On Cloudflow, be it the classic or Cloudflow 2 and Cloudflow 3. Those who can, will remember Tim Don doing the Iron Man Brazil in under eight hours. When you first see the Cloudflow 4 you are taken aback at how different it really is. Changes to the design of the shoe make it unreal to look at. The upper material is probably where they have made the most significant changes. The Cloudflow 4 has a much sleeker and race-ready upper than the Cloudflow 3.

Technical Aspects

Cloudflow 3 Cloudflow 4
Weight: 238 g 235 g
Heel-to-toe: 8 mm 8 mm
Midsole/Outsole: Grip rubber compound with enhanced traction pattern. Outsole: Grip rubber pads for enhanced traction.
Midsole: Dual-density Helion™ superfoam for impact absorption.
Sustainability: Recycled content:
– Total recycled content: about 20%
– Polyester: about 70% recycled
Recycled content:
– Total recycled content: about 25%
– Polyester: about 75% recycled
Speedboard®: Made from polypropylene and shaped for speed. Made from Mapex for improved stiffness and strength for greater lightness and performance.
Upper: 70% of the polyester content, and 20% of the entire shoe, is from recycled materials. Engineered woven upper made from 100% recycled polyester.

Changes to the Speedboard® material and construction have made for an improved return of energy for the athlete, making it even closer to a racing high-performance shoe than before. The newly engineered upper is very close in look to the On Cloudboom Echo 2, again pushing this shoe towards the performance racing category. Some water resistance is present, but the shoe breathes well in hot conditions. The upper is also much thinner than its predecessor.

The sole of the shoe has some well-received changes as well. The outer sole has more grip and the midsole now has dual-density Helion™ superfoam. When one glances at the cloud technology of the old and new Cloudflow, the difference is apparent. I am not entirely sure about the exact measurement, but I can see the clouds on the Cloudflow 4 are larger than the Cloudflow 3. This enhances impact absorption for the runner.

After testing this shoe, I can agree that there is more cushion in the Cloudflow 4 than the Cloudflow 3. The Speedboard™ has also now become hidden. There was always a concern with the older versions around stones getting stuck in the groove that ran down the middle of the sole, but no more. It looks sleek and fast now.

The Cloudflow 4 sticks to the DNA of the Cloudflow 3 in being built for speed, tempo sessions and short runs up to 21km. As we have seen on the Iron Man circuit, this shoe can be used for marathons. We have seen the switch even among elite athletes to more cushioned shoes for racing. I still feel the Cloudflow 4 will have its place in racing, and depending on your build, a marathon is not out of the question with this shoe!

Closing Thoughts

The upgrades to the Cloudflow 4 have elevated its spot in the On cloud arsenal. We all know everyone wants high cushion for comfort these days, but you still have your speedsters and triathletes that prefer the less cushion, stiffer shoe for racing. I feel that the Cloudflow 4 does exactly that. The high-toe box pushes the run with fall action, using gravity to propel you forward. The sole is hard, which is perfect for racing, but still has enough cushion for comfort. The shoe has great grip on slippery roads, and the new light upper construction has an element of water resistance but not too much. Where do I see this shoe fitting in for the consumer? My thoughts are this is a perfect 5km, 10km, up to 21km or even 41km (depending on your build) for the average athlete who isn’t a top 10 runner, but still wants a high-performance running shoe that won't break the bank. I feel it fits in between the high-performance Cloudstratus and the Cloudboom Echo for racing.

This is an all-around great shoe for speed and will be a welcome addition to the racing range of shoes. Once I have dropped some weight, I'm sure I will enjoy them in a racing environment as well!

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