https://matteocampagna.com/en/registry/equipment/string-material-bow-vibration 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/string-material-bow-vibrationThere is a single measurement, and it concerns the Japanese bow. Ten university kyudo archers shot with four strings, Kevlar, Technora, Vectran and hemp, fifty shots per string, with strain gauges on the bow near the grip. The material changes how quickly the vibrations die away, not the frequency at which the bow vibrates: the spectra are almost identical with every string, while the logarithmic decrement of bending runs from 0.61 with Kevlar to 0.70 with hemp and that of twisting from 0.32 with Technora to 0.51 with hemp, with almost every pair different from the others. The exceptions show that the difference is not always clear-cut, since Kevlar and Technora damp twisting in the same way and Technora and Vectran damp bending in the same way. The archers notice, but only just: in the free comments after each shot hemp collects more remarks on vibration and impact than would be expected, with a chi-square of 12.69 against a threshold of 12.59, and Kevlar is left out of that analysis because it was the usual string of eight archers out of ten. The models explain why the question makes sense but do not answer it: in 1981 a calculation with an elastic string leaves 22 per cent of the energy in the string and limbs after the arrow leaves and predicts two vibration frequencies instead of one, and in 2007 a model of the recurve estimates that the peak force in the string comes just after the arrow leaves, at about seven times the draw weight, without counting the damping that the kyudo study measures. On a modern recurve or compound, with stabilisers and dampers, there are no measurements.claim:corda-materiale-vibrazioni-arco:revision:2026-01-14:2Wed, 14 Jan 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/string-material-bow-vibrationclaim:corda-materiale-vibrazioni-arco:new_claim:2026-01-13:riportatoTue, 13 Jan 2026 08:00:00 GMT