Overview
ISO 6267:1980 specifies a laboratory test method to determine the bending vibration natural frequency and damping time of alpine skis. The method applies to skis of nominal length 150 cm or more. The ski is rigidly clamped in the binding area so that the free front section vibrates; vibrations are recorded with an inductive displacement transducer and analyzed to extract period, frequency and damping metrics.
Key Topics
- Mounting and conditioning: The ski is conditioned at 23 ± 5 °C and encastrated (clamped) in a fixture located at the mounting zone. The clamping device must have a mass of at least 100 kg to avoid resonance effects and should use a flat jaw plus three clamps (30 mm wide) spaced at least 150 mm apart.
- Excitation and trigger: An excitation (mechanical deflection or mass) imposes an initial flexion. The triggering device must not introduce torsional vibration or shock and should be placed no more than 200 mm from the ski tip.
- Initial deflection and measurement: The prescribed initial flexion at the measurement point is 2.5 ± 0.5 mm; the initial amplitude used for evaluation should correspond as closely as possible to a 2 mm flexion at the measurement point. The subsequent 30 vibrations are used for evaluation.
- Transducer and recording: Vibrations are measured with an inductive displacement transducer attached to the fixture and recorded on a recorder for graphical analysis.
- Computed quantities:
- Period of vibration (T): time between successive peaks.
- Natural frequency (f): f = 1 / T.
- Alternative calculation: T = t30 / 30, where t30 is the time for 30 complete vibrations.
- Damping time (t1/2): time required for the vibration amplitude to reduce to half its initial value while the ski is vibrating.
Applications
This standard provides a reproducible mechanical test for manufacturers, test laboratories and researchers concerned with ski dynamic behavior. Typical uses:
- Product development: Compare bending vibration properties across prototypes to refine flexural design.
- Quality control: Verify that production skis meet specified dynamic response ranges.
- Performance and safety assessment: Assess vibration characteristics that can influence ride stability and skier feedback.
The method yields objective metrics (frequency, period, damping time) that support repeatable comparisons between ski models and batches.
Related Standards
- ISO 6267:1980 was developed by ISO/TC 83 (sports and outdoor equipment).
- Complementary documents typically cover binding mounting procedures, environmental conditioning of sports equipment, and mechanical test methods for skis and related gear. Users should consider other ISO or national standards on ski bindings and mechanical testing when designing a complete test program.
Keywords: ISO 6267:1980, alpine skis, bending vibration, natural frequency, damping time, inductive transducer, clamped mounting, test method.
