Fitting the vanes at a slight angle tightens the group
2 studies
The summary today
The two tests available come from the same researcher, shoot a compound from a machine and point the same way. In the first, at thirty metres, the group of arrows with vanes angled at about a quarter of a degree was less than half that of the same arrows with straight vanes, but the work does not say how many arrows were shot or give the values. The second, at twenty-five metres with four X7 2315 arrows shot several times each, measures the diameter of the circle containing every hole: with shafts straight to a thousandth of an inch the group goes from 39 millimetres with straight vanes to 27 at 0.9 degrees and 20 at 2.1 degrees, and with shafts straight to three thousandths from 48 to 30 and 28. The biggest gain comes with the first degree. The authors put it down to spin: an arrow that rotates spreads the sideways push from the small imperfections of the shaft in every direction, rather than leaving it always on the same side. What is missing is a test from another laboratory, one with an archer or a recurve, and one at long distances.
Also phrased as: "offset vanes"; "angled fletching"; "fletch angle"; "straight or offset vanes"; "offset and grouping"
In practice
Archers who fletch their own arrows are told to give the vanes a little offset, because an arrow that spins groups better than one that flies without rotating.
Evidence
-
2011
For Equipment tests Published later
A set of arrows shot from a compound on a machine, first with the vanes parallel to the shaft and then angled at about 0.25 degrees: at 30 m the standard deviation of the group with angled vanes was less than half that with straight vanes. Number of arrows and values not reported.
The aerodynamic drag and axial rotation of an arrow · J L Park
-
2017
For Equipment tests Published later
Hoyt Pro Comp Elite compound of 240 N on a Hooter Shooter machine at 25 m, four X7 2315 arrows with MicroLite Super nocks shot ten times each (elsewhere the methods say eight), group measured as the diameter of the smallest circle containing every hole. Shafts straight to ±0.001 inches: 39 mm with vanes at 0 degrees, 27 at 0.9 and 20 at 2.1; to ±0.003: 48, 30 and 28 mm. No statistical analysis; the authors give 1 to 2 degrees as a sufficient angle, and 2 degrees as about the most a typical vane will take on the shaft.
Effect of arrow shaft straightness on arrow grouping · James L Park, Patrick J Aitchison, Adam J Bielby, Vincent Bleakley, Trent P Carberry, Richard M Ellis, Richard D Kerner, Andrew D MacDonald, Danie Oosthuizen, Scott B Pankhurst, Konstantinos Psarakis
Status history
- 2011 Reported The first test: a set of compound arrows shot from a machine, first with the vanes parallel to the shaft and then angled at about a quarter of a degree. At thirty metres the group with angled vanes is less than half that with straight vanes, comparing standard deviations. The work does not say how many arrows were shot or give the values, and the test takes up one paragraph of an article on aerodynamic drag. It is a test on equipment, which counts as direct evidence in a claim about equipment, but there is only one and it is thinly documented: reported.
- 2017 Reported The same researcher, with a team from four countries, repeats the comparison more carefully: four X7 2315 arrows shot at twenty-five metres from a compound on a machine, with three vane angles and two grades of straightness, ten shots per arrow according to the methods, which elsewhere give eight. With shafts straight to a thousandth of an inch the group goes from 39 millimetres at zero degrees to 27 at 0.9 degrees and 20 at 2.1 degrees; with shafts straight to three thousandths from 48 to 30 and 28. The effect appears at both straightness grades and grows with the angle, but with no statistics and from the same laboratory: the picture grows stronger without becoming independent, and stays reported.
Related
Related articles
Research lines
Cite
Campagna, M. (2026). Fitting the vanes at a slight angle tightens the group (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/angled-vanes-group-size
@misc{campagna2026_aletteinclinategruppo,
author = {Campagna, Matteo},
title = {Fitting the vanes at a slight angle tightens the group},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/angled-vanes-group-size},
note = {Version 1; accessed 2026-10-16}
}
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