https://matteocampagna.com/en/registry/equipment/points-vanes-drag 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/points-vanes-dragThe two halves of this sentence are not equally solid. On the vanes the measurements point the same way, and the effects are large when the fletchings really differ: in a magnetic suspension wind tunnel the vanes roughly double the drag of the bare shaft, from a coefficient of about 0.75 to about 1.5, and between two models of straight vane the coefficient goes from 1.56 to 2.05; outside that tunnel, untrimmed hunting feathers produce about three times the drag of parabolic ones, and with a wooden bow the energy loss over the first five metres runs from 1.93 per cent with four inch feathers to 7.5 with the shortest, and over 12 with flu-flu fletchings. It is also the vane, not the tube or the point, that switches the layer of air from the low-drag regime to the high-drag one. Between two competition vanes, one with three quarters of the other's area, the difference can vanish, though: shot by an archer from her recurve, arrows with Spin Wing and with Gas Pro vanes gave the same coefficient, 2.68 against 2.63, because the flexing of the shaft made the boundary layer turbulent in both cases; and a repeat run by the same Japanese group did not confirm the low-drag regime for one vane model. On the point the picture is narrower than the way it is told on the range. With the shaft held aligned with the airflow, bullet and streamlined points give the same drag; the difference appears when the point creates a step or a taper behind its widest part, because that is where the layer of air separates, and with that geometry the arrow slows down more. Even then the calculated effect stays at a few per cent: on a compound arrow the point accounts for 4 per cent of the drag, a bulge point lengthens the drift at seventy metres by about 5 millimetres out of 156, and a point designed to keep the first stretch of shaft laminar would shorten it by 8 per cent. Finally, nobody has taken the comparison to the target: there is no study in the bibliography that measures archers' scores or groups with different points and vanes.claim:punte-alette-resistenza:revision:2026-10-01:3Thu, 01 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaA measurement in the magnetic suspension wind tunnel quantifies the most solid half, the vanes: a drag coefficient of 2.05 with large straight vanes against 1.56 with short ones, all else being equal. The same year, in Belgium, with a wooden bow held in a mechanical device, the energy loss over the first five metres runs from 1.93 per cent with four inch feathers to 7.51 with two and a half inch ones, and over 12 with flu-flu fletchings. From Australia a calculation sizes up the point half: a point designed to keep the first stretch of shaft laminar would take 8 per cent off the drift at seventy metres. Vanes change drag a great deal when they are very different; the point changes it by a few points: reported.claim:punte-alette-resistenza:history_entry:2026-08-06:2020Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaThe Japanese group has an expert woman archer shoot the same arrow from her recurve, 36 times with Spin Wing vanes and 36 with Gas Pro: the drag coefficient is 2.68 against 2.63, in other words the same. According to the authors the flexing of the shaft makes the point's angle of attack oscillate by about 3.7 degrees, and at an angle like that the boundary layer is turbulent with both vanes. It is the first comparison of two vanes on arrows actually shot from a bow, and it goes against the vane half, but it concerns two competition vanes not far apart, one with three quarters of the other's area, and a single archer, while the large differences measured so far concern very different fletchings: the status stays reported.claim:punte-alette-resistenza:history_entry:2026-08-06:2017Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaA water tunnel and a wind tunnel in China look at the flow over the vanes: at zero incidence it stays attached on helical plastic vanes and separates on flat straight ones, while changing the point does not move lift and moment beyond the repeatability of the measurement. These are mostly qualitative observations, with no drag values, in a venue flagged as questionable: the status does not change.claim:punte-alette-resistenza:history_entry:2026-08-06:2014Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaThe measurements spread from the tunnel to free flight and the picture sharpens. The bare shaft with the point alone stays in the low-drag regime and its value matches the theoretical figure for a cylinder; with the vanes the drag roughly doubles, and vanes of smaller area add less of it. With the same vanes, on the other hand, the shape of the point does not change the drag when the arrow is held aligned to the flow, and the nock does not count either, because it sits inside the already thick layer of air at the rear. In the same work an expert national-team archer shoots the arrow with Spin Wings from her recurve, and all her shots fall in the high-drag regime. In the same year, outside that laboratory, a sensor fitted in the tip of a crossbow bolt finds that two hunting heads of almost identical mass slow it in a similar way, with a mean deceleration of 1,385 against 1,441 thousandths of a g over four shots each: it is a small test, on something other than a target arrow, and it stays context. The status stays reported because the fullest tests come from the same rig and the same group, and the outside one from 2007 is a single shot per arrow.claim:punte-alette-resistenza:history_entry:2026-08-06:2012Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaThe first measurements in a magnetic suspension wind tunnel arrive. With the vanes fitted and the arrow spinning, the layer of air switches to the high-drag regime at a speed twenty-five per cent lower and the drag coefficient rises by about half a point, while without vanes it is the shape of the point that decides whether the flow stays attached. A second paper on the same rig, on a crossbow bolt, finds coefficients from 1.0 to 1.9 across three point shapes. The same year, in Australia, a water channel shows why the point matters: behind a short bulge point the flow separates on the taper and the whole shaft is turbulent, while with a bullet point it stays laminar for a stretch. But the same author's calculations put the effect in proportion: on a compound arrow the point accounts for 4 per cent of the drag and the vanes for 12, and the bulge lengthens the drift at seventy metres by 5 millimetres out of 156. Direct tests on the equipment, none on the target: reported.claim:punte-alette-resistenza:history_entry:2026-08-06:2011Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaThe first measurement comes from sound. Two arrows identical except for their fletching pass over three microphones, and the Doppler effect of the point's whistle shows how much they slow down: the drag constant is about three times higher with untrimmed hunting feathers than with parabolic ones. It is one shot per arrow, in a thirteen metre room, with two fletchings worlds apart, and it says nothing about the point: reported, on the vane half.claim:punte-alette-resistenza:history_entry:2026-08-06:2007Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-drag#storiaThe first person to treat the arrow with the methods of aeronautics calculates drag as friction on the surface and puts the feathers into a factor multiplying the area of the shaft: 1.02 for the celluloid vanes of flight arrows, up to 1.50 for hunting feathers. On that calculation large feathers would add up to half the drag, but the factors come from geometry and nobody has measured anything yet: not studied.claim:punte-alette-resistenza:history_entry:2026-08-06:1933Thu, 06 Aug 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/points-vanes-dragclaim:punte-alette-resistenza:new_claim:2026-05-28:riportatoThu, 28 May 2026 08:00:00 GMT