How high you grip the pole — the dial that follows your approach speed, never the other way round. About 7.6 cm more grip height feels like a 2.3 kg softer pole.
Approach speed, pole stiffness and grip height are one system, not separate dials: change one without the others and you either produce a soft pole you blow through or a stiff one that barely bends. The order is always speed, then grip, then pole. The expensive mistake is running it backwards — buying a stiffer pole in order to jump higher. Without the speed it simply does not bend enough, your cleared height drops despite the “better” equipment, and the risk rises. That speed leads is not a coach's opinion: approach speed explains about 67% of the height differences among world-class vaulters, and 6% more speed delivers roughly 13% more usable energy at the plant. What gets missed: never change two variables at once — and a pole's flex rating is only comparable within the same series.