Overview
ISO/TR 5262:2023 - Motorcycles - Guideline for verification of total running resistance force during mode running on a chassis dynamometer - provides evidence-based guidance for establishing pass/fail thresholds when verifying the performance of an electric inertial chassis dynamometer. The technical report focuses on how changes in inertial settings and running-resistance elements affect measured fuel consumption and the evaluation items defined by ISO 18580. It is applicable when the dynamometer’s running resistance force is set in accordance with ISO 18580.
Key topics and technical requirements
- Scope and applicability
- Verification guidance for dynamometers that simulate inertia electrically (no mechanical flywheel), used during WMTC mode running tests.
- Applicable when running resistance is configured per ISO 18580.
- Evaluation metrics (ISO 18580 evaluation items analyzed)
- Correlation coefficient (γ)
- Slope (A) and intercept (B) of the regression line between target and measured running resistance
- Relative standard deviation (σ / cov)
- Integral work error (e)
- Factors studied
- Equivalent inertia (mechanical and electrical), front-wheel rolling resistance, aerodynamic (wind) loss, dead time, and rise time of the dynamometer control.
- Test methods
- Vehicle tests using WMTC Type I cycles on representative motorcycle models (various classes, transmission types and displacements).
- Simulation tests to assess effects of controlled dead time and rise time.
- Fuel consumption is calculated from exhaust gas data per the method/formula provided in the report.
- Outcome
- Relationship curves and regression analyses linking changes in fuel consumption to the ISO 18580 evaluation items, enabling guideline thresholds for pass/fail decisions.
Practical applications - who uses this standard
- Vehicle and powertrain test laboratories validating chassis dynamometer setups for motorcycle certification.
- Motorcycle manufacturers verifying dyno-based emissions and fuel-consumption test reproducibility.
- Dynamometer manufacturers implementing and validating electric inertia control algorithms and specifying permissible dead time/rise time.
- Regulatory bodies and compliance engineers establishing objective thresholds for verification under ISO 18580 and WMTC-related testing.
- R&D teams studying impacts of rolling resistance, aerodynamic drag and inertia settings on measured fuel consumption.
Related standards
- ISO 18580 - Verification of total running resistance force during mode running on a chassis dynamometer (primary normative reference).
- WMTC (Worldwide harmonized Motorcycle Test Cycle) procedures and Global Technical Regulation No. 2 (vehicle selection and test cycle relevance).
ISO/TR 5262:2023 is a practical complement to ISO 18580, helping laboratories and manufacturers interpret verification results, set defensible thresholds, and improve repeatability when using electric inertial chassis dynamometers for motorcycle testing.