https://matteocampagna.com/en/registry/equipment/arrow-matching-weight-spine 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/arrow-matching-weight-spineTwo independent bodies of evidence say the same thing, and neither has archers shooting. The first comes from the test bench: within one nominal spine group the real stiffness varies a great deal, to the point that in a dynamic identification two neighbouring carbon spines, 500 and 600, come out indistinguishable, 34.5 against 35.3 Hz, while the factory figures predicted a clear difference. The second comes from the shooting machine: on fifty-nine Easton X10 shafts of the same spine, measured one by one and shot at seventy metres, out of two hundred and fifty-five combinations of parameters the closeness of the arrows on the target is best explained by mass, mean spine and the frequency with which stiffness varies around the shaft, that is by something more than weight and spine alone. The same measurement shows that the weight already varies in the shafts and the points, with ranges three to five times the declared tolerance, while nocks and vanes weigh almost the same, and that in the assembled arrows the range reaches 0.282 g: matching heavy points with light shafts would bring the range down to 0.027 g. The counterweight has to be stated. Those same fifty-nine arrows, not matched for weight, still held a vertical spread of 8.8 cm at seventy metres, that is inside the ten ring, which measures 12.2 cm. A calculation by the same group, on twenty-six dozen X10s that did not meet the declared weight tolerance, points the same way: within each dozen the arrows would stay in the ten, and points would be lost only by mixing different dozens. Matching matters, but it is not what separates a ten from a nine, and the step into practice, with archers and a set selected two different ways, has not yet been taken.claim:selezione-frecce-peso-spine:revision:2026-09-02:3Wed, 02 Sep 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-matching-weight-spine#storiaA Korean study of hunting arrows shot by machine at 40 m confirms that within a single model the factory measurements of weight, diameter, straightness and spine vary, and that the spread of the three impacts of an arrow turned through 120 degrees ranges from under two millimetres to two centimetres. It does not link those parameters to the group of each arrow, though, and has no statistical tests: it is context, and the status stays reported.claim:selezione-frecce-peso-spine:history_entry:2026-08-31:2016Mon, 31 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-matching-weight-spine#storiaAn independent dynamic measurement reaches the same conclusion by another route: within one nominal spine group the identified stiffness varies widely, in carbon as in aluminium and cedar, and two neighbouring carbon spines come out indistinguishable to the measurement while the factory figures predicted a clear difference. Damping varies widely too between arrows of the same model. In the same year a conference abstract weighs twenty-six dozen X10s and none stays within the declared weight tolerance, but its calculation says that within each dozen the arrows would still stay in the ten at seventy metres: it confirms that the declared weight has to be measured, not that measured weight and spine are not enough, and it stays context. The authors of the dynamic measurement admit they cannot separate production variability from clamping error, so two coherent bodies of evidence but none on archers: reported.claim:selezione-frecce-peso-spine:history_entry:2026-07-17:2019Fri, 17 Jul 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-matching-weight-spine#storiaA recurve model puts figures on something archers say on the field: two shafts of different models with the same nominal spine need different draw weights to tune, 175.5 against 180 N, and one percentage point of difference in the elastic modulus shifts the impact by twenty-five millimetres at seventy metres. In the same year a laser vibrometer measurement on three specimens per model of carbon shafts finds that within one model the first bending frequency barely varies, with a standard deviation of 0.4 Hz, while the differences grow at the higher frequencies: arrows of the same model are alike on the main bending mode, and the figures do not compare the arrows of a set with each other. In that year the claim therefore rests on a calculation alone: transferred.claim:selezione-frecce-peso-spine:history_entry:2026-07-17:2012Fri, 17 Jul 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-matching-weight-spineclaim:selezione-frecce-peso-spine:new_claim:2026-06-01:riportatoMon, 01 Jun 2026 08:00:00 GMT