On Cloudboom Strike LS vs On Cloudboom Strike:
Which to Choose

Underfoot these two are near-identical twins: the same resilient, springy superfoam, the same carbon plate steering an aggressive forward rocker, and the same trait of feeling tall and slightly tippy at jogging speed before settling into a smooth, propulsive stride once you commit to pace. Both sit on a tall platform right up near the 40mm race limit with a low 4mm drop, both are rated low on stability with no pronation support, and both land in essentially the same fast optimal zone (roughly 3:00–3:30 min/km). Where they split is construction and weight. The standard Cloudboom Strike uses a breathable engineered mesh upper with conventional laces, so you can dial in midfoot security and it holds up better to repeated use; it comes in around 7.6 oz (215g) in a men's sample and its sweet spot stretches a touch shorter, excelling from the 10K up through the marathon. The LS replaces that with a seamless, sprayed LightSpray upper — no laces, no seams — which drops the weight to roughly 6.5 oz (184g) and gives the lightest, most locked-in feel On makes, at the cost of adjustability: the fit is fixed and snug rather than tunable. Both shoes carry the warning that thin racing outsoles wear quickly and should be saved for key sessions and race day.