How the Year’s Most Innovative Sneaker Flipped the Script on Super Shoes

With spray-on uppers made by robots, On’s laceless running shoes are just as cool as they sound.

Published December 30, 2024

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Updated December 30, 2024

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When Hellen Obiri broke away from the pack during this year’s Boston Marathon, few spectators questioned whether the defending the champ would win the world’s most prestigious road race.

Instead, the only thing anyone could ask was, “What the hell are those shoes?”

They turned out to be an unreleased version of the year’s most intriguing model, the On Cloudboom Strike LS, which feature a laceless upper sprayed on by robots.

It’s just as cool as it sounds.

GP100 Winner

On Cloudboom Strike LS

Specs

Stack Height	39.5mm
Heel-to-Toe Drop	4mm
Weight	170 grams (six grams)

$330 at On

Intricately simple

To appreciate the shoes fully is to recognize the thing they’re destined to replace.

Traditional uppers are engineering marvels. Hundreds of materials come together across complex steps that range from yarn extrusion to gluing everything in place.

But more steps mean more waste, more overseas manufacturing and, as far as runners are concerned, more weight on their feet. In other words, slower times.

By comparison, these LS uppers, short for LightSpray, are made using an automated manufacturing process developed by On.

Robotic arms spray the upper onto a mold with single piece of synthetic monofilament — similar to how a spider weaves its web. Then, the upper attaches to the midsole with a patent-pending thermal bonding technique.

The whole process, which can be done anywhere in the world, takes three minutes from start to finish and cuts down the carbon emissions up to 75 percent, the company claims. One shoe weighs just 170 grams (six ounces).

To date, super shoes have largely been defined by foams and plates. There are likely still gains to be made in these areas, but they’re marginal at most — with every major brand on a race to the bottom.

Even if spray-on uppers aren’t the final frontier, they’ve at least given the industry somewhere else to run.