The spine recommended by manufacturers' charts is the spine top archers actually use
2 studies · 16 archers measured
The summary today
The only data on archers is an observation made in passing, but a clear one. In high-speed video of 16 recurve archers from national teams, eight men and eight women filmed at the London Olympic test event, arrow stiffness was in every case the one the manufacturer's charts give for their draw weight and arrow length, and fifteen of the sixteen were shooting the same shaft model. Draw weights and lengths were as stated by the archers, and the shafts had very probably been chosen from the charts in the first place: the observation says that the best archers follow the charts, not that the charts point to the best shaft. On that second question there is only a 2025 numerical model, not yet checked experimentally, which broadly reproduces the commercial charts but finds them too stiff, by up to four sizes, for long arrows and low draw weights, and notes that they move in steps of 4 to 6 pounds and one inch, while in many rows half an inch of arrow is already enough to change the recommended shaft. For the statement as it stands, then, there is one observation of sixteen archers, with no comparison against archers who depart from the charts.
Also phrased as: "spine chart"; "choosing spine from the Easton chart"; "the manufacturer's chart is reliable"; "arrow selection chart"
In practice
Archers are told always to start from the manufacturer's chart, crossing actual draw weight with arrow length, and then to refine with tuning, because that is what the best archers do.
Evidence
-
2012
For Archers Published later
High-speed video of 16 recurve archers from national teams, eight men and eight women, filmed at the London Olympic test event in October 2011: in every case arrow stiffness matched what the manufacturer's selection charts would predict for the bow's draw weight and the arrow's length; fifteen were shooting Easton X10 and one Easton ACE. Draw weights and lengths are as stated by the archers, and the study does not say how the shafts had been chosen.
High-speed video analysis of arrow behaviour during the power stroke of a recurve archery bow · James L Park, Oliver Logan
-
2025
Context Model Published later
Park's model rewritten and solved combination by combination, with the criterion of a shaft that leaves without rotating in the horizontal plane, produces charts for Easton X7 and X10 from 20 to 52 pounds and from 25 to 32 inches: broadly consistent with Easton's. In most cells the shaft chosen by the model keeps a residual rotation below 20 degrees per second, which the author says small adjustments of draw weight and button will correct. A university project in a student journal, and the new charts have not been checked by shooting.
Modelling Arrow Dynamics for Optimised Recurve Archery Arrow Selection · Alex Williams
-
2025
Context Model Published later
At the extremes the same model finds the charts too stiff: in the X7 for long arrows, all the more at extreme draw weights, in the X10 at low draw weights, by up to four sizes softer and never more than one size stiffer. The Easton charts move in steps of 4 to 6 pounds and one inch, the model's in steps of 4 pounds and half an inch, and in many rows half an inch changes the recommended shaft.
Modelling Arrow Dynamics for Optimised Recurve Archery Arrow Selection · Alex Williams
Status history
- 2012 Reported The first observation on archers: in video of 16 recurve archers from national teams at the London Olympic test event, arrow stiffness was in every case consistent with the manufacturer's charts for that draw weight and length, and fifteen of the sixteen were using the same shaft model. It is an observation rather than an outcome, based on figures stated by the archers, and the shafts had very probably been chosen from the charts in the first place: there is evidence in favour and it is limited: reported.
- 2025 Reported A numerical model of lateral flex, not yet checked experimentally, produces charts broadly consistent with the commercial ones, but finds the commercial charts too stiff at the extremes, by up to four sizes: for long arrows and extreme draw weights in the X7, for low draw weights in the X10. It also notes that the charts move in steps of 4 to 6 pounds and one inch, where half an inch already changes the shaft. It addresses how sound the charts are, not what archers use, so the status stays where it was in 2012.
Related
Related articles
- The archer's paradox: the physics of the flexing arrowAt full draw the arrow points to one side and still reaches the centre: how it flexes and clears the riser in the first twenty milliseconds, and how spine matches it to the bow.
- How to choose arrow spine and read the manufacturer's chartHow to choose arrow spine: what it is, why draw weight at your draw length matters, how to read a manufacturer's chart and how to check it by shooting.
- Choosing and matching competition arrowsWhich spine to choose and how alike the arrows in a dozen are: charts, weight, the stiff side of the shaft, straightness and nocks, as studies measure them.
Research lines
Cite
Campagna, M. (2026). The spine recommended by manufacturers' charts is the spine top archers actually use (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/manufacturer-spine-charts
@misc{campagna2026_tabellespineproduttori,
author = {Campagna, Matteo},
title = {The spine recommended by manufacturers' charts is the spine top archers actually use},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/manufacturer-spine-charts},
note = {Version 1; accessed 2026-10-16}
}
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