This robot is making On’s spray-on marathon sneaker, its fastest-ever distance shoe

In 2024, Kenyan long-distance runner Hellen Obiri beat her compatriots Sharon Lokedi and Edna Kiplagat to win that year’s Boston Marathon – her second victory on the famously undulating course, and at that point her third marathon major (she added a fourth at the 2025 New York Marathon). On her feet? An intriguing pair of laceless sneakers by Swiss sportswear brand On, a prototype of what would become the On Cloudboom Strike. ‘Is this the craziest sneaker you have ever seen?’ read a headline on The New York Times at the time.

Crazy not only because they were without laces, like a sock with a bouncing carbon-plated sole, but because they were constructed using ‘spray on’ technology, their upper created in a single step by a robotic arm in On’s headquarters in Zurich (the On Labs are not only a head office, but a place for technological development – Wallpaper* took a visit in 2022). The process, taking just three minutes per shoe, sees a shoe last steadily coated with a single-filament polymer to create an ultra-light, stretchy mesh (the web-like construction has seen them colloquially deemed the ‘Spiderman’ shoe).

Hellen Obiri in LightSpray On Sneakers

Hellen Obiri, four-time marathon major champion, in a pair of LightSpray Cloudmonster 3 Hyper sneakers

(Image credit: On)

Used for both the Cloudboom Strike, the brand’s fastest racing sneaker, and the more recent Cloudmonster 3 Hyper, for training runs, the trademarked process is called ‘LightSpray’. ‘It’s pioneering because it completely reinvents how a shoe upper is made,’ Scott Maguire, On’s president and COO, tells Wallpaper*. ‘It moves it from a complex, multi-step assembly process to a revolutionary single-step – the ultralight uppers are literally sprayed, not built, which condenses the approximately 200 traditional assembly steps into a single three-minute process.’ (He also notes that beyond efficiency, LightSpray ‘minimises waste and reduces CO2 emissions’.)

Opening today (24 April), in anticipation of the London Marathon this Sunday (26 April) – in which Obiri will compete, marking her London debut – the On LightSpray robot has arrived in the city at a special pop-up in Hanover Square. Created in collaboration with PlayLabs, visitors over the weekend will have the opportunity to watch the robot in action, try on the new sneakers and participate in a series of ‘movement sessions’ and workshops (On has also partnered with Healf, the online wellbeing and supplements platform, on the community activations). Meanwhile, a series of audio clips, played throughout the space, see Obiri recount her experiences running in the Cloudboom Strike (she also visited for a pre-launch event yesterday).

On LightSpray installation in London

The On LightSpray robot in situ at the London pop-up

(Image credit: On)

‘The ultimate proof of [the Cloudboom Strike’s] performance for marathon running was the latest victories we [have] celebrated – Yemen Crippa winning the marathon in Paris, Solveig Lovseth and Kristian Blummenfelt winning the Ironman in Texas and Hellen Obiri’s record-breaking New York City Marathon victory last fall,’ says Maguire. ‘This technology enables unparalleled precision in engineering every part of the upper structure to meet specific performance needs. The core benefit is bringing championship-level innovation – validated by elite athletes – into a radically new running shoe that is now accessible to all runners.’ (The LightSpray sneakers are available in limited-edition drops.)

The London opening coincides with the recent launch of the LightSpray Cloudmonster 3 Hyper, the first sneaker to be created in a new facility in Busan, South Korea. The factory, which is dedicated to the LightSpray technology, allows the brand to scale-up production in order for consumers – and not just high-performing athletes – to get their hands on the sneakers. ‘It’s a pivotal milestone for On,’ says Maguire, who calls the site a ‘robot farm’ (plans for further ‘farms’ in more locations will unfold in the coming years). ‘It houses 32 robots, allowing us to to increase LightSpray product volume by 30-fold. We are intentionally moving the technology beyond limited drops for elite athletes to integrate LightSpray into a much wider range of products for our entire community.’ Watch this space.

The On LightSpray Tour London is open from 24-26 April, 2026.

Register for the various events here.

Also read: The 20 best running brands in the world, according to Wallpaper*

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