https://matteocampagna.com/en/registry/equipment/limb-geometry-energy-transfer Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/equipment/limb-geometry-energy-transferThe mathematical models of a single author say so, from 1991 to 2007, with a result that runs against intuition: storing more energy is not enough, what matters is how much of it is passed to the arrow. At equal draw weight and draw length, the modern recurve with limbs that work right out to the tips combines stored energy of 0.434 with an efficiency of 0.770, and launches the arrow faster than any other bow compared, with a velocity coefficient of 2.09. Bows with rigid ears store more than straight bows, from 0.432 to 0.491 against 0.395 to 0.407, but pass on less, with efficiencies from 0.619 to 0.668, because when the string leaves the bridges the thrust on the arrow drops suddenly and sets off an oscillation that uses up energy; in the end their arrow goes about as fast as that of a straight bow. Pushing the curvature to the extreme almost doubles the stored energy, up to 0.810, and almost halves the efficiency, which falls to 0.417. As early as 1991 the same author drew a consequence from this that bears on the claim: because the bows that store more pass on a smaller share, at equal draw weight and draw length the arrow's speed changes little from one bow to another, and shape parameters matter less than is claimed. Geometry decides the share of the stored energy that passes to the arrow, while the energy the arrow actually receives changes much less. These are, however, figures from a model: it was checked against the draw weight of a longbow replica, to within 1 per cent, and against the arrow speed of a single modern bow, where the measured efficiency came out a few points below the calculated one. It compares historical types, not the limbs on sale today, and no measurement on equipment has yet compared different geometries with everything else held equal.claim:geometria-flettenti-trasferimento:revision:2026-04-23:3Thu, 23 Apr 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/limb-geometry-energy-transferclaim:geometria-flettenti-trasferimento:new_claim:2026-03-04:trasferitoWed, 04 Mar 2026 08:00:00 GMT