The Cloudflow 5 is On's long-running tempo shoe, now running Helion HF hyper foam through CloudTec tuned for pace, with a glass-fiber-infused nylon Speedboard doing the propelling. It is the speed-day sibling to the Cloudmonster family — the shoe that firms up where they bounce.
It suits you for tempo runs, intervals, and shorter races: quick sessions where you want structure and snap without committing a carbon racer.
It is not soft — this has always been the firm On, and easy miles in it feel like a misunderstanding. It also now costs $180, which buys several plated super trainers; the Flow's case is feel, not arithmetic.