The new On Running Cloudracer is made to compete as the fastest shoe in the world. According to the results of a study by the Swiss Federal Institute of Technology (the ‘MIT of Europe’), the On Running CloudTec outsole ’empowers you to run with lower heart rate’ compared to other leading running shoe – save essential energy to win. The skeleton-design of the upper shoe holds your foot with minimal weight.

The Cloudracer combines an ultra-lightweight skeleton-design with On Running’s patented CloudTec 3D cushioning system. The CloudTec elements will keep your impact light while giving you extra force on push-off.

High-grade EVA extends the midsole durability while a lightweight sock provides an anatomical fit. A highly dense ‘Integrated Transition Bridge’ provides propulsion and efficiency while the ‘Flight-Control-Pad’ on the insole stimulates foot proprioception for quicker reflexes.

The uppers ‘skeleton-design’ holds the foot with minimal weight and the liner mesh with smart foam adapts to the foot for comfort – seamless. A nylon heel strap provides easy entry. Additionally, the lightweight and welded eye stay enables easy lacing and intelligent side-stitching secures the perfect tongue positioning. The perforated tongue provides comfort without sacrificing breathability.

The outsole is made of 18 CloudTec elements that provide 3D cushioning and interlock directly with the midsole for a firm and direct push-off. CloudTec rubber compound offers durability and a honeycomb-slip-pattern provides grip on and off the road.

The Cloudracer in US Men’s Size 10.5 weighs in at 10.0 ounces and has a heel to toe differential between 5mm to 6mm. Lighter than the Cloudsurfer by about 1.5 ounces but still on the heavy side for a racing shoe.

So did the Cloudracer perform to expectations? I reviewed its predecessor, the Cloud Surfer, over a year ago. This is the shoe that I have waited over a year for – it addresses a lot of the issues I have with the Cloudsurfer: weight, bulkiness, breathability, flexibility, cushioning. It is lighter in weight and at least a 10X improvement in breathability with its skeleton-uppers! Cushioning is reduced and it is not as flexible as a lot of shoes in the market today. But it is still too bulky for a racing shoe – great for training though.

If you’ve been running with the Cloudsurfer, Cloudrunner, or Cloudster, then upgrading to the Cloudracer is a no-brainer. But to me, it is still not a minimal shoe just as Newton shoes are not minimal shoes – they’re all neutral, transitioning shoes in my book.

The Cloudracer also comes with an additional set of laces for customization – orange and white. A little detail that I noticed on the aglets (small plastic sheath at the end of shoelace) of these laces: ‘Put Me On’.

I’ve been testing various different minimal shoes with a heart rate monitor over a controlled environment (terrain, distance, time of day, elapsed time) for a personal project. So far, I haven’t concluded if certain shoes make you run with a lower heart rate (preferably aerobic). More time is needed and results need to be double-verified (by re-running) but the problem is over time, you get faster (Maffetone training). With that in mind, I cannot say that the Cloudracer ’empowers you to run with lower heart rate’…

The Cloudracer reminded me of the Newton MV2 and in fact, there were conflicting reports about the energy return system (ERS) used in Newton shoes and On Running shoes – who invented it first or who stole from who. I’ll leave this to the conspiracy theorists. But comparing the MV2 to the Cloudracer, I prefer the fit (MV2 is way too narrow on the forefoot) and technology (hard to adjust to the MV2 lugs) of the Cloudracer – I did NOT get injured running in them. The Cloudracer is bulkier and if they can shave off 3 ounces from the midsole and outsole by making it thinner and more flexible, this can be a favorite racing shoe for a lot of runners.

Looking closely at the removable insole/insert, I noticed the text ‘Secret Weapon May Self-Destruct After 222 KM’. Does that mean it is meant to be a racing-only shoe? Because long training runs (222 KM is about 138 miles) might reduce the racing life of this shoe…

There is a single colorway for both men and women (unisex): Silver with Orange. The On Running Cloudracer is now available at: On Running

*Product provided by On Running (MSRP $130). CMP.LY/1 Review

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