Nocking point height needs to be set to the millimetre
1 study
The summary today
The only work that calculates how much nocking point height matters runs against the claim, but it models a single bow. On a 166 newton recurve with a 600-spine X10, the calculation finds a height, 1.62 millimetres above the rest in the model's geometry, at which the arrow leaves without rotating in the vertical plane. Around that point the minimum is gentle: a millimetre either way changes the arrow's rotation by about 8 degrees per second and keeps the angle of attack under 0.2 degrees, and moving to the next spine shifts the best height by only 0.2 millimetres. The arrow leaves the rest after 0.7 milliseconds, so what sets its vertical launch is mainly the path of the nock on the string. On a shooting machine, with the nocking point set, fletched and bare shafts landed less than 20 millimetres apart vertically at 20 metres, a result consistent with rotation under 10 degrees per second; with the arrow raised 10 millimetres on the string, by contrast, the tear in paper at 2 metres grew to 40. An error of a centimetre shows straight away, one of a millimetre, in the model, hardly at all. The limit is a serious one: the model holds the string exactly at the nocking point, whereas an archer holds it with three fingers, and no study in the registry has tried different heights with archers shooting.
Also phrased as: "nocking point height"; "setting the nocking point"; "nocking point to the millimetre"; "vertical bare shaft tuning"; "how high to set the nocking point"
In practice
At clubs the nocking point is set with a bracing square and adjusted half a millimetre at a time, on the idea that even one millimetre too many sends arrows high or low.
Evidence
-
2013
Against Model Published later
In the model the best height is a gentle minimum and sensitivity is low: a millimetre either way of nocking point height changes the arrow's angular velocity by about 8 degrees per second, and the initial angle of attack stays positive and under 0.2 degrees (p. 22).
Arrow behaviour in the vertical plane during and immediately following the power stroke of a recurve bow · James L Park
-
2013
Context Model Published later
A flexible-beam model of a 68-inch Hoyt Nexus recurve (166 N, 220 mm brace) with a 21.65 g, 600-spine X10: with the nocking point 1.62 mm above the rest, measured at brace, the arrow leaves with zero angular velocity in the vertical plane and a residual angle of attack of 0.03 degrees; rotation and angle of attack cannot both be brought to zero. The height belongs to the model's geometry, not to a bracing square reading.
Arrow behaviour in the vertical plane during and immediately following the power stroke of a recurve bow · James L Park
-
2013
Context Model Published later
Repeating the calculation with X10s of the adjacent spines, behaviour in the vertical plane changes little and the best nocking point height moves by only 0.2 mm for one spine size.
Arrow behaviour in the vertical plane during and immediately following the power stroke of a recurve bow · James L Park
-
2013
Context Model Published later
In the model the arrow stops touching the rest after 0.7 ms, and the highest force on the rest, 0.14 N, is at full draw before release. Removing the rest force altogether moves the best height from 1.62 to 1.60 mm: what sets the arrow's vertical launch is the path of the nock, not the rest.
Arrow behaviour in the vertical plane during and immediately following the power stroke of a recurve bow · James L Park
-
2013
Context Equipment tests Published later
The author's recurve on a shooting machine, with the string pushed to the left at release to imitate it leaving the middle finger. With the nocking point set, fletched and bare shafts land less than 20 mm apart vertically at 20 m, consistent with an angle of attack of about zero and angular velocity under 10 degrees per second; in the paper test at 0.8, 2, 5, 8, 10 and 12 m, point and fletching pass less than 1 mm apart. With the arrow raised 10 mm on the string, the tear at 2 m becomes 40 mm. Heights in between, from one to ten millimetres, were not tried.
Arrow behaviour in the vertical plane during and immediately following the power stroke of a recurve bow · James L Park
Status history
- 1990 Not studied No work in the registry's bibliography had yet calculated how much the arrow's rotation at launch depends on nocking point height. Care to the millimetre was handed down with the bracing square and the bare shaft test, with no figure for what a millimetre is worth: the claim had not been studied.
- 2013 Contradicted A recurve model, a 166 newton Hoyt Nexus with 600-spine X10 arrows, finds a nocking point height, 1.62 millimetres above the rest, at which the arrow leaves the bow without rotating in the vertical plane. That height is not critical, though: a millimetre either way changes the rotation by about eight degrees per second, and moving to a neighbouring spine shifts the optimum by two tenths of a millimetre. The arrow leaves the rest after seven tenths of a millisecond and the rest pushes on it with very little force. On a shooting machine, with the best setting, fletched and bare shafts land within two centimetres of each other vertically at twenty metres, while an arrow raised a centimetre on the string tears the paper by 40 millimetres. The only evidence, a model checked on a machine, runs against the claim, and it is indirect: contradicted.
Related
Related articles
- The parts of an Olympic recurve bow, one by oneThe parts of an Olympic recurve bow, from riser and limbs to arrow rest and clicker: what each one is called, what it does and what the rules allow.
- Fishtailing and porpoising: what arrow flight saysDoes your arrow wag sideways or wave up and down? What causes fishtailing and porpoising, which to fix first, and how to confirm it with a bare shaft test.
- Bow tuning in archery: how to tune your bow, backed by scienceBow tuning and the research: spine, centre shot, button, nocking point, brace height and tiller. What models and machine tests show, and how precise you need to be.
Research lines
Cite
Campagna, M. (2026). Nocking point height needs to be set to the millimetre (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/nocking-point-height-to-the-millimetre
@misc{campagna2026_puntoincoccomillimetro,
author = {Campagna, Matteo},
title = {Nocking point height needs to be set to the millimetre},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/nocking-point-height-to-the-millimetre},
note = {Version 1; accessed 2026-10-16}
}
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