ISO 11486:2006

Motorcycles - Methods for setting running resistance on a chassis dynamometer

ISO 11486:2006 specifies the measurement method for determining the motorcycle running resistance on the road, and two methods of setting the chassis dynamometer with the motorcycle running resistance. It is applicable to motorcycles as defined in ISO 3833.

Motocycles — Méthodes pour fixer la résistance à l'avancement sur un banc dynamométrique

General Information

• Status: Published
• Publication Date: 28-Aug-2006
• ICS: 43.140 - Motorcycles and mopeds
• Technical Committee: ISO/TC 22/SC 38 - Motorcycles and mopeds
• Drafting Committee: ISO/TC 22/SC 38 - Motorcycles and mopeds
• Current Stage: 9093 - International Standard confirmed
• Start Date: 02-Apr-2021
• Completion Date: 13-Dec-2025

Relations

• Amended By: ISO 11486:2006/Amd 1:2012 - Motorcycles - Methods for setting running resistance on a chassis dynamometer - Amendment 1
• Effective Date: 09-May-2020
• Revises: ISO 11486:1993 - Two-wheeled motorcycles - Fuel consumption measurements - Chassis dynamometer setting by coastdown method
• Effective Date: 15-Apr-2008

Overview

ISO 11486:2006 - "Motorcycles - Methods for setting running resistance on a chassis dynamometer" defines standardized methods to determine and reproduce a motorcycle’s running resistance on a chassis dynamometer. The standard describes a measured on‑road method (the coastdown method) and a simpler running resistance table (table method) for setting dynamometer load and inertia. It is intended for motorcycles as defined in ISO 3833 and supports reliable fuel consumption and exhaust emission testing by ensuring consistent dynamometer settings.

Key topics and technical requirements

• Scope and methods
  • Two primary setting methods: coastdown method (individual on‑road measurement) and table method (inertia-based approximation).
  • Applicable for exhaust emission and fuel consumption testing where dynamometer running resistance must match on‑road behaviour.
• Road test requirements
  • Road: flat, level, straight, smoothly paved; slope ≤ 0.5 %.
  • Ambient limits: wind steady; max wind speed 3 m/s (gusts 5 m/s); temperature range 278 K to 308 K; relative humidity ≤ 95 %.
  • Standard ambient reference: pressure 100 kPa, temperature 293 K, reference air density 1.189 kg/m³.
• Speeds and measurements
  • Defines specified speeds (at least four points including the reference speed) and reference speed(s) used to calculate target resistance.
  • Coastdown start speed must be sufficiently above the measurement start to allow procedures (see standard).
• Accuracy and instrumentation
  • Measurement accuracy requirements include: running resistance force ±2 %; motorcycle speed ±1 % (resolution 0.45 km/h); coastdown time ±0.5 % (0.01 s); total motorcycle mass ±1.0 %.
  • Annexes specify required documentation: motorcycle description (Annex A) and dynamometer/instrument description (Annex B).
• Data processing
  • Procedures for calculating running resistance, curve fitting, deriving target running resistance forces, inertia settings, warming‑up, tyre pressure and verification checks.

Applications and users

ISO 11486:2006 is used by:

• Motorcycle manufacturers for certification and R&D.
• Independent test laboratories performing fuel consumption and exhaust emissions measurements.
• Regulatory agencies and homologation bodies requiring reproducible dynamometer settings.
• Chassis dynamometer manufacturers and calibration engineers implementing target resistance and inertia settings. Practical benefits: consistent on‑road to laboratory correlation, reproducible test results, and compliance with international test procedures.

Related standards

• ISO 3833 - Road vehicles: types, terms and definitions (applicability to motorcycle definitions).
• ISO 7117 - Motorcycles: measurement of maximum speed. For implementation, follow the instrument and test method requirements referenced in ISO 11486:2006 and the applicable emission or fuel consumption test standards.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11486
Second edition
2006-09-01
Motorcycles — Methods for setting
running resistance on a chassis
dynamometer
Motocycles — Méthodes pour fixer la résistance à l'avancement sur un
banc dynamométrique
Reference number
©
ISO 2006
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 2
5 Test motorcycle, chassis dynamometer and instruments . 3
6 Required accuracy of measurements. 4
7 Road test. 4
7.1 Requirement for road . 4
7.2 Ambient conditions for the road test. 4
7.3 Reference speed . 5
7.4 Specified speed. 5
7.5 Coastdown starting speed. 5
7.6 Coastdown time measurement beginning speed and ending speed . 5
7.7 Preparation of test motorcycle. 5
7.8 Rider and riding position . 6
7.9 Measurement of coastdown time. 6
8 Data processing. 8
8.1 Calculation of running resistance force. 8
8.2 Running resistance curve fitting. 8
8.3 Target running resistance force for chassis dynamometer setting . 8
9 Chassis dynamometer setting derived from on-road coastdown measurements. 8
9.1 Requirements for the equipment . 8
9.2 Inertia mass setting . 9
9.3 Warming up of chassis dynamometer. 9
9.4 Adjustment of tyre pressures. 9
9.5 Motorcycle warming up. 9
9.6 Procedures for setting chassis dynamometer . 9
9.7 Verification of chassis dynamometer. 12
10 Chassis dynamometer setting using the running resistance table. 12
10.1 Applicability. 12
10.2 Requirements for the equipment . 12
10.3 Setting the running resistance force on the chassis dynamometer . 14
10.4 The specified speed for the chassis dynamometer . 14
10.5 Verification of chassis dynamometer. 14
Annex A (normative) Motorcycle description. 15
Annex B (normative) Chassis dynamometer and instruments description. 17
Annex C (informative) Record of coastdown time and chassis dynamometer setting. 19
Bibliography . 22

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11486 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 22,
Motorcycles.
This second edition cancels and replaces the first edition (ISO 11486:1993), which has been technically
revised.
iv © ISO 2006 – All rights reserved

Introduction
While ISO 11486:1993 gave only a running resistance setting method by coastdown method for the purpose
of fuel consumption measurement, this edition of ISO 11486 has been prepared with the aim of establishing
the general setting method that is usable for both exhaust emission testing and fuel consumption testing
covering high-speed range driving.
In addition to the coastdown method, the table method is introduced in this edition of ISO 11486. In the
coastdown method, the running resistance of each motorcycle is measured individually on the road, and the
measured running resistance is reproduced on a chassis dynamometer. The table method is a simple setting
method, where the running resistance value of the motorcycle is determined only with its equivalent inertia
mass.
When this International Standard is applied to the exhaust emission test or the fuel consumption test, it is
essential to follow the requirements specified in those test methods.
INTERNATIONAL STANDARD ISO 11486:2006(E)

Motorcycles — Methods for setting running resistance on a
chassis dynamometer
1 Scope
This International Standard specifies the measurement method for determining the motorcycle running
resistance on the road, and two methods of setting the chassis dynamometer with the motorcycle running
resistance. It is applicable to motorcycles as defined in ISO 3833.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3833, Road vehicles — Types — Terms and definitions
ISO 7117, Motorcycles — Measurement of maximum speed
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
running resistance
F
total force resistant to a running motorcycle which, when measured by the coastdown method, includes the
friction forces in the drive-train
3.2
reference speed
v
motorcycle speed at which the running resistance of the motorcycle is calculated and then used for setting the
chassis dynamometer
3.3
specified speed
v
motorcycle speed at which the running resistance on the road is measured to determine the running
resistance curve
3.4
motorcycle kerb mass
m
k
motorcycle dry mass to which is added the mass of the following:
⎯ fuel: tank filled at least to 90 % of the capacity specified by the manufacturer;
⎯ oils and coolant: filled as specified by the manufacturer;
⎯ auxiliary equipment usually supplied by the manufacturer in addition to that necessary for normal
operation [tool-kit, carrier(s), windscreen(s), protective equipment, etc.]
3.5
motorcycle reference mass
m
ref
kerb mass of the motorcycle increased by a uniform figure of 75 kg, which represents the mass of a rider
4 Symbols
For the purposes of this document, the symbols in Table 1 apply.
Table 1 — Symbols
Symbol Definition Unit
a The coefficient of polygonal function —
b The coefficient of polygonal function —
c The coefficient of polygonal function —
a The rolling resistance force of front wheel N
T
b The coefficient of aerodynamic N/(km/h)
T
d The relative air density under test conditions —
T
d The standard ambient relative air density —
F The running resistance force N
F The set running resistance force on the chassis dynamometer N
E
F (v ) The set running resistance force at the reference speed on the chassis dynamometer N
E 0
F (v ) The set running resistance force at the specified speed on the chassis dynamometer N
E i
F The total friction loss N
f
F (v ) The total friction loss at the reference speed N
f 0
F The running resistance force N
j
F (v ) The running resistance force at the reference speed N
j 0
F The braking force of the power absorbing unit N
pau
F (v ) The braking force of the power absorbing unit at the specified speed N
pau j
F (v ) The braking force of the power absorbing unit at the reference speed N
pau 0
F The running resistance force obtained from the running resistance table N
T
*
F The target running resistance force N
*
F The target running resistance force at the specified speed N
j
*
F (v ) The target running resistance force at the reference speed on the chassis dynamometer N
*
F (v ) The target running resistance force at the specified speed on the chassis dynamometer N
i
f The rolling resistance N
*
f The corrected rolling resistance in the standard ambient conditions N
f The coefficient of aerodynamic drag N/(km/h)
* 2
f The corrected coefficient of aerodynamic drag in the standard ambient conditions N/(km/h)
2 © ISO 2006 – All rights reserved

Table 1 (continued)
Symbol Definition Unit
K The temperature correction factor for rolling resistance —
m The test motorcycle mass kg
m The actual mass of the test motorcycle kg
a
m The equivalent inertia mass kg
i
m The flywheel equivalent inertia mass kg
fi
m The motorcycle kerb mass kg
k
m The equivalent inertia mass of all the wheels kg
r
m The motorcycle reference mass kg
ref
m The rider mass kg
rid
m The rotating mass of the front wheel kg
rf
m The equivalent inertia mass of the rear wheel and the motorcycle parts rotating with the wheel kg
r1
p The standard ambient pressure kPa
p The mean ambient pressure during the test kPa
T
T The mean ambient temperature during the test K
T
T The standard ambient temperature K
v The specified speed km/h
v The specified speeds which are selected for coastdown time measurement km/h
j
v The reference speed km/h
v The speed at which the measurement of the coastdown time begins km/h
v The speed at which the measurement of the coastdown time ends km/h
∆T The corrected coastdown time at the inertia mass (m +m) s
E
i r1
∆T The average coastdown time at the specified speed s
i
∆T The average coastdown time of the two tests s
j
∆T The target coastdown time s
road
∆t The coastdown time s
∆t The mean coastdown time on the chassis dynamometer without absorption s
∆t The mean coastdown time on the chassis dynamometer at the reference speed s
E
∆t The coastdown time measured during the first road test s
ai
∆t The coastdown time measured during the second road test s
bi
∆t The coastdown time corresponding to the reference speed s
i
∆v The coastdown speed interval (2∆v = v − v) km/h
1 2
ε The chassis dynamometer setting error —
ρ The standard relative ambient air volumetric mass kg/m
5 Test motorcycle, chassis dynamometer and instruments
A full description of the motorcycle shall be provided in accordance with Annex A.
A full description of the chassis dynamometer and instruments shall be provided in accordance with Annex B.
6 Required accuracy of measurements
Measurements shall be made to the accuracies as specified in Table 2.
Table 2 — Required accuracy of measurements
Parameter At measured value Resolution
a) Running resistance force, F +2 % —
b) Motorcycle speed (v ,v ) ±1 % 0,45 km/h
1 2
c) Coastdown speed interval [2∆v = v − v ] ±1 % 0,10 km/h
1 2
d) Coastdown time (∆t) ±0,5 % 0,01 s
e) Total motorcycle mass [m + m ] ±1,0 % 1,4 kg
k rid
f) Wind speed ±10 % 0,1 m/s
g) Wind direction — 5 deg.
h) Ambient temperature — 2 K
i) Barometric pressure — 0,2 kPa
7 Road test
7.1 Requirement for road
The test road shall be flat, level, straight and smoothly paved. The road surface shall be dry and free of
obstacles or wind barriers that might impede the measurement of the running resistance. The slope of the
surface shall not exceed 0,5 % between any two points at least 2 m apart.
7.2 Ambient conditions for the road test
During data collecting periods, the wind shall be steady. The wind speed and the direction of the wind shall be
measured continuously or with adequate frequency at a location where the wind force during coastdown is
representative.
The ambient conditions shall be within the following limits:
⎯ maximum wind speed: 3 m/s;
⎯ maximum wind speed for gusts: 5 m/s;
⎯ average wind speed, parallel: 3 m/s;
⎯ average wind speed, perpendicular: 2 m/s;
⎯ maximum relative humidity: 95 %;
⎯ air temperature: 278 K to 308 K.
Standard ambient conditions shall be as follows:
⎯ pressure, p : 100 kPa;
⎯ temperature, T : 293 K;
4 © ISO 2006 – All rights reserved

⎯ relative air density, d : 0,9197;
T
⎯ air volumetric mass, ρ : 1,189 kg/m .
The relative air density when the motorcycle is tested, calculated in accordance with the formula below, shall
not differ by more than 7,5 % from the air density under the standard conditions.
The relative air density, d , shall be calculated by the following formula:
T
p T
T 0
dd=× × (1)
T0
p T
0T
7.3 Reference speed
The reference speed or speeds shall be as defined in the test cycle.
7.4 Specified speed
The specified speed, v, is required to prepare the running resistance curve. To determine the running
resistance as a function of motorcycle speed in the vicinity of the reference speed, v , running resistances
shall be measured using at least four specified speeds, including the reference speed(s). The range of
specified speed points (the interval between the maximum and minimum points) shall extend either side of the
reference speed or the reference speed range, if there is more than one reference speed, by at least ∆v, as
defined in 7.6. The specified speed points, including the reference speed point(s), shall be no greater than
20 km/h apart and the interval of specified speeds should be the same. From the running resistance curve, the
running resistance at the reference speed(s) can be calculated.
7.5 Coastdown starting speed
The coastdown starting speed shall be more than 5 km/h above the highest speed at which coastdown time
measurement begins, since sufficient time is required, for example to settle the positions of both the
motorcycle and rider and to cut the transmitted engine power off before the speed is reduced to v , the speed
at which the measurement of the coastdown time is started.
7.6 Coastdown time measurement beginning speed and ending speed
To ensure accuracy in measuring the coastdown time, ∆t, and coastdown speed interval, 2∆v, the beginning
speed, v , and ending speed, v , in kilometres per hour, the following requirements shall be met:
1 2
vv=+∆v (2)
vv=−∆v (3)
∆v shall be 5 km/h when v is less than 60 km/h, and shall be 10 km/h when v is 60 km/h or more.
7.7 Preparation of test motorcycle
7.7.1 The motorcycle shall conform in all its components with the production series, or, if the motorcycle is
different from the production series, a full description shall be given in the test report.
7.7.2 The engine, transmission and motorcycle shall be properly run in, in accordance with the
manufacturer’s requirements.
7.7.3 The motorcycle shall be adjusted in accordance with the manufacturer’s requirements, e.g. the
viscosity of the oils, tyre pressures, or, if the motorcycle is different from the production series, a full
description shall be given in the test report.
7.7.4 The kerb mass of the motorcycle shall be as defined in 3.4.
7.7.5 The total test mass, including the masses of the rider and the instruments, shall be measured before
the beginning of the test.
7.7.6 The distribution of the load between the wheels shall be in conformity with the manufacturer’s
instructions.
7.7.7 When installing the measuring instruments on the test motorcycle, care shall be taken to minimize
their effects on the distribution of the load between the wheels. When installing the speed sensor outside the
motorcycle, care shall be taken to minimize the additional aerodynamic loss.
7.8 Rider and riding position
7.8.1 The rider shall wear a close-fitting suit (one-piece) or similar clothing, a protective helmet, eye
protection, boots and gloves.
7.8.2 The rider in the conditions given in 7.8.1 shall have a mass of 75 kg ± 5 kg and be 1,75 m ± 0,05 m
tall.
7.8.3 The rider shall be seated on the seat provided, with his feet on the footrests and his arms normally
extended. This position shall allow the rider at all times to have proper control of the motorcycle during the
coastdown test.
The position of the rider shall remain unchanged during the whole measurement period.
7.9 Measurement of coastdown time
7.9.1 After a warm-up period, the motorcycle shall be accelerated to the coastdown starting speed, at which
point the coastdown measurement procedure shall be started.
7.9.2 Since it can be dangerous and difficult from the viewpoint of its construction to have the transmission
shifted to neutral, the coasting may be performed solely with the clutch disengaged. For those motorcycles
that have no way of cutting the transmitted engine power off prior to coasting, the motorcycle may be towed
until it reaches the coastdown starting speed. When the coastdown test is reproduced on the chassis
dynamometer, the transmission and clutch shall be in the same condition as during the road test.
7.9.3 The motorcycle steering shall be altered as little as possible and the brakes shall not be operated until
the end of the coastdown measurement period.
7.9.4 The first coastdown time, ∆t , corresponding to the specified speed, v, shall be measured as the
ai j
elapsed time from the motorcycle speed v + ∆v to v − ∆v.
j j
7.9.5 The procedure from 7.9.1 to 7.9.4 shall be repeated in the opposite direction to measure the second
coastdown time, ∆t .
bi
7.9.6 The average ∆T of the two coastdown times ∆t and ∆t shall be calculated by the following equation:
i ai bi
∆∆tt+
ai bi
∆T = (4)
i
7.9.7 At least four tests shall be performed and the average coastdown time, ∆T , calculated by the following
j
equation:
n
∆∆TT= (5)
j ∑ i
n
i1=
6 © ISO 2006 – All rights reserved

Tests shall be performed until the statistical accuracy, P, is equal to or less than 3 % (P u 3 %).
The statistical accuracy, P, as a percentage, is calculated by the following equation:
ts 100
P=× (6)
∆T
n
j
where
t is the coefficient given in Table 3;
s is the standard deviation given by the following formula:
n
()∆∆TT−
ij
s= (7)
∑
n−1
i1=
n is the number of tests.
Table 3 — The coefficient for the statistical accuracy
t
n t
n
4 3,2 1,60
5 2,8 1,25
6 2,6 1,06
7 2,5 0,94
8 2,4 0,85
9 2,3 0,77
10 2,3 0,73
11 2,2 0,66
12 2,2 0,64
13 2,2 0,61
14 2,2 0,59
15 2,2 0,57
7.9.8 In repeating the test, care shall be taken to start the coastdown after observing the same warm-up
procedure and at the same coastdown starting speed.
7.9.9 The measurement of the coastdown times for multiple specified speeds may be made by a continuous
coastdown. In this case, the coastdown shall be repeated after observing the same warm-up procedure and at
the same coastdown starting speed.
7.9.10 The coastdown time shall be recorded. The example of the record form is given in C.1.
8 Data processing
8.1 Calculation of running resistance force
8.1.1 The running resistance force, F, in newtons, at the specified speed, v, shall be calculated by the
j j
following equation:
12∆v
Fm=× +m× (8)
()
jr
3,6 ∆T
j
m should be measured or calculated as appropriate. As an alternative, m may be estimated as 7 % of the
r r
unladen motorcycle mass.
8.1.2 The running resistance force, F , shall be corrected in accordance with 8.2.
j
8.2 Running resistance curve fitting
The running resistance force, F, shall be calculated as follows:
This following equation shall be fitted to the data set of F and v obtained above by linear regression to
j j
determine the coefficients f and f ,
0 2
F=+ffv (9)
The coefficients f and f determined shall be corrected to the standard ambient conditions by the following
0 2
equations:
*
ff=+⎡⎤1KT−T (10)
()
00 0 T 0
⎣⎦
p
T
* T 0
ff=× × (11)
Tp
0T
K may be determined based on the empirical data for the particular motorcycle and tyre tests, or may be
−3 −1
assumed as follows if the information is not available: K = 6 × 10 K .
8.3 Target running resistance force for chassis dynamometer setting
*
The target running resistance force, F (v ), on the chassis dynamometer at the reference motorcycle
speed, (v ), in newtons, is determined by the following equation:
***2
Fvf=+f×v (12)
()
00 2 0
9 Chassis dynamometer setting derived from on-road coastdown measurements
9.1 Requirements for the equipment
9.1.1 The instrumentation for the speed and time measurement shall have the accuracies as specified in
Clause 6.
9.1.2 The chassis dynamometer rollers shall be clean, dry and free from anything which might cause the
tyre to slip.
8 © ISO 2006 – All rights reserved

9.2 Inertia mass setting
9.2.1 The equivalent inertia mass for the chassis dynamometer shall be the flywheel equivalent inertia mass,
m , closest to the actual mass of the motorcycle, m . The actual mass, m , is obtained by adding the rotating
fi a a
mass of the front wheel, m , to the total mass of the motorcycle, rider and instruments measured during the
rf
road test. Alternatively, the equivalent inertia mass, m, can be derived from Table 4. The value of m , in
i rf
kilograms, may be measured
...