Abstract

This report compares the empirical findings from the Quad X vane series testing with theoretical

and computational data from the University of Colorado Boulder and Iron Will Outfitters.

Primary parameters evaluated include velocity loss over distance, rotational behavior (RPS),

aerodynamic drag (C_D), and stabilization dynamics. The analysis demonstrates that small-

profile vanes such as the Flex Fletch Quad X maintain aerodynamic efficiency even at steep

helical offsets, with minimal velocity penalties and improved stability characteristics.

1. Introduction

Arrow fletching design affects aerodynamic drag, rotation rate, and stabilization. Traditional

assumptions suggest that higher helical offsets increase drag, which may lead to greater velocity

loss. However, small vanes with low profiles may mitigate this trade-off. This study evaluates

these effects using real-world test data from Flex Fletch Quad X vanes and published CFD

analyses from Iron Will.

2. Methods

2.1 Quad X Testing (PNL Testers)

• Shaft: Black Eagle Carnivore 350, 26.5” C2C

• FOC: 16.5%2

© 2025, PNL TESTERS. All Rights Reserved.

• Total weight: 380.5 gr

• Offsets: 1°, 3°, 5° (measured with a 5C spin indexer)

• Velocity: 285.3 fps ± 0.5

• Instrumentation: LabRadar, paper tuning, index tracking

• Metrics: RPS, RPM, deviation recovery, and velocity at intervals from 0 to 60 yards

2.2 Iron Will Testing (CU Boulder Senior Design Project)

• CFD simulations with SolidWorks Flow Simulation

• Experimental indoor/outdoor shots at 40 yards using Hoyt RX5

• Variables: vane height, shape, fletch angle, and profile thickness

3. Results

3.1 Velocity Loss Over Distance

Helical Offset V0 (fps) V60 (fps) Total Loss % Loss

1° 286.2 260.0 26.2 -9.15%

3° 287.0 260.0 27.0 -9.41%

5° 286.0 259.0 27.0 -9.44%

Observation: Differences in velocity loss between 1° and 5° are negligible (<1 fps).

3.2 Rotational Behavior

Helical Offset RPS (V0) RPM (V0)

1° 24.9 1495.7

3° 48.5 2912.0

5° 63.7 3819.4

Observation: Increased helical offset significantly boosts spin rate, enhancing gyroscopic

stability.

3.3 Stabilization (Paper Test)

Paper tears were tracked from 1 to 15 yards. Primary deviation peaks occurred at 3 yards,

followed by a secondary deviation peak near 5 yards for all setups. The 5° offset showed reduced

overall deviation and a smoother stabilization curve.

Key Finding: Higher spin rate reduced lateral deviation, though recovery time (distance) was not

drastically shortened.3

© 2025, PNL TESTERS. All Rights Reserved.

3.4 Drag and Aerodynamic Efficiency (C_D)

According to Iron Will's data:

• Taller vanes produce lower drag coefficients (0.77 vs. 0.83 for shorter variants)

• Smooth, low-profile vanes with streamlined shapes exhibit lower pressure drag

Quad X vanes likely exhibit efficient drag profiles due to their low height (0.4") and smooth

parabolic contour.

4. Discussion

• Iron Will's CFD findings align with real-world data from Quad X tests: increasing helical

offset does not significantly increase total drag when using small-profile vanes.

• The performance improvements in rotation and stability from a 5° offset come with no

meaningful loss in velocity.

• High RPS does not appear to introduce excess drag, countering widespread assumptions

in traditional archery circles.

5. Conclusion This comparative analysis affirms that increasing helical offset on small vanes

such as the Quad X provides meaningful improvements in rotation and stability without

significant drag penalties. For compound archers using fixed-blade broadheads or shooting in

windy environments, a 3° to 5° offset configuration is recommended. The Iron Will theoretical

framework supports these conclusions and confirms the aerodynamic efficiency of streamlined

vane shapes.

6. References

• University of Colorado Boulder. (2024). Drag and Vanes in Archery Hunting.

• University of Colorado Boulder. (2024). Restoring Torque and Stability in Arrows.

• University of Colorado Boulder. (2024). Vane Height and Its Effects on Performance.

• Newman, E. (2025). Quad X Fletching Performance Series, Parts 1–3.

• NASA Glenn Research Center. (2022). What is Drag?

• Park, J. (2023). Arrows: How to Minimise Drag and Maximise Lift. Bow International.