On has been building toward this shoe for a while, and the Cloudboom Strike LS represents a genuine leap forward — not just in performance, but in how a racing shoe is made. The headline is the LightSpray upper, a construction process that sprays a continuous filament directly onto the shoe's form in a single step, with no glue, no seams, no laces, and no overlapping layers. The result is an ultra-featherweight second-skin fit that eliminates distraction completely, letting you focus entirely on the race from gun to tape.

Beneath that groundbreaking upper, the performance platform is every bit as serious. Helion HF superfoam delivers a lightweight, highly responsive ride, while a drop-in Bounceboard layer amplifies energy return even further. A full-length carbon fiber Speedboard with a spoon-shaped profile drives maximum forward propulsion, and minimal CloudTec elements smooth the roll-through with each stride rather than interrupting it. The combination makes the Cloudboom Strike LS feel fast in a way that's almost effortless — efficient, propulsive, and surprisingly smooth for a shoe built purely around speed.

A grippy, generously applied rubber outsole provides the traction confidence you need when racing at full effort on road surfaces. As On's lightest and most technically advanced road racing shoe to date, the Cloudboom Strike LS is built for one purpose — helping serious runners chase down personal records at any distance.

MIDSOLE

• Helion™ HF is 40% bio-based Pebax superfoam that provides an unparalleled underfoot experience.
• Full-length carbon fiber Speedboard® provides rigidity for energetic toe-offs and efficient strides. 
• Bounceboard is a thick drop-in layer of Helion™ HF immediately underfoot, allowing direct compression of the foam for maximum energy return.
• CloudTec® elements are strategically placed to create a smooth roll-through, increasing running efficiency. 

OUTSOLE

• Unique rubber compound offers next-level traction across variable road conditions. 

UPPER

• LightSpray™ filament forms the entire ultra-thin and mesh-like upper, weighing just 30 g (1.0 oz) for On's lightest upper ever. Spun by a specialized robot in a single 3-minute step, it provides a seamless second-skin fit that's breathable, elastic, and supportive enough for racing. It reduces upper-related carbon emissions by 75%.