ISO 9838:2023

Overview

ISO 9838:2023 - Alpine and touring ski-bindings - Test soles for ski‑binding tests - specifies laboratory test soles and test bodies used for reproducible ski‑binding testing. It defines two primary test sole forms: form A (alpine ski‑boot representation, types A for adults and C for children) and form T (touring ski‑boot representation). The standard also defines test bodies to verify free space and dimensional fit for bindings designed to work with boots having improved walking soles (per ISO 23223). ISO 9838:2023 is the fifth edition and updates dimensions and adds Clause 8 for test bodies.

Key topics and technical requirements

• Materials and construction
  • Test soles are moulded in TPU (polyurethane) with a metal reinforcement insert; form T includes a glued rubber sole (68 ± 5 Shore A).
  • Soles are produced with consistent surface roughness to ensure uniform friction at the sole/binding interface.
• Dimensions and tolerances
  • Basic test sole lengths: 305 mm (type A), 255 mm (type C); variable lengths available (type A: 270–360 mm; type C: 200–280 mm).
  • Dimensional tolerances follow the tables in the standard (length, radii, angles ±0.5°).
• Mechanical properties and test methods
  • Flexional stiffness: three‑point support deflection test at 23 °C ±5 °C (loads: type A = 400 N; type C = 200 N).
  • Compressional stiffness: axial compression test (loads: type A = 500 N; type C = 250 N).
  • Hardness: Shore D on form A soles (ISO 868); Shore A on form T rubber.
  • Coefficient of friction: determined per ISO 5355.
  • Thermal expansion: length change measured between 23 °C and −20 °C.
  • Tabled acceptance limits are provided for deflection, residual deformation, hardness, friction and dilation.

Applications and users

• Who uses ISO 9838:2023
  • Binding and boot manufacturers for design validation and production quality control.
  • Independent test laboratories and certification bodies conducting binding release and impact tests (in support of ISO 9462, ISO 9465, ISO 13992).
  • R&D teams developing alpine and touring bindings or walking‑sole interfaces.
  • Standards committees and conformity assessors verifying dimensional fit for boots with improved walking soles (ISO 23223).
• Practical value
  • Ensures reproducible, repeatable test conditions across labs by standardizing the test sole geometry, material and mechanical behaviour.
  • Helps detect wear, changes in friction or dimensional drift - test soles are reusable but must be rechecked periodically.

Related standards

• ISO 9462, ISO 9465 (alpine binding test methods)
• ISO 13992 (alpine touring bindings)
• ISO 5355, ISO 9523, ISO 23223 (boot interfaces and walking soles)

Keywords: ISO 9838:2023, test soles, ski‑binding tests, alpine ski‑bindings, touring ski‑bindings, TPU test sole, Shore hardness, flexional stiffness, binding test standards.