Document ID: chunk:federal_register_of_legislation:F2008C00323:reg:21:p1
Version: federal_register_of_legislation:F2008C00323
Segment Type: reg
Provision Reference: reg 21 (pt 1/7)
Character Range: 219904–223079

21                Idle               13                            20                20          400                 PM (1)

                   (1) PM = gearbox on neutral, clutch engaged.
                           K1,K5 = first or fifth gear engaged, clutch disengaged

                   (2) Additional gears can be used according to manufacturer recommendations if
       the vehicle is equipped with a transmission with more than five gears.
Figure 1/3

Extra-urban cycle (Part Two) for the Type I test

Annex 4 - Appendix 2

CHASSIS DYNAMOMETER

         1.  DEFINITION OF A CHASSIS DYNAMOMETER WITH FIXED LOAD CURVE

         1.1.  Introduction

         In the event that the total resistance to progress on the road cannot be reproduced on the chassis dynamometer between speeds of 10 km/h and 120 km/h, it is recommended that a chassis dynamometer having the characteristics defined below should be used.

         1.2.  Definition

         1.2.1. The chassis dynamometer may have one or two rollers.
         The front roller shall drive, directly or indirectly, the inertial masses and the power absorption device.

         1.2.2. The load absorbed by the brake and the chassis dynamometer internal frictional effects between the speeds of 0 and 120 km/h is as follows:

                                     F =  (a + b.V2) ± 0.1.F80  (without being negative)

         where:

            F  = total load absorbed by the chassis dynamometer (N)
            a = value equivalent to rolling resistance (N)
            b = value equivalent to coefficient of air resistance (N/(km/h)2)
            V = speed (km/h)
             F80 =   load at 80 km/h (N).

         2. METHOD OF CALIBRATING THE DYNAMOMETER

         2.1.  Introduction

         This Appendix describes the method to be used to determine the load absorbed by a dynamometer brake. The load absorbed comprises the load absorbed by frictional effects and the load absorbed by the power-absorption device.

         The dynamometer is brought into operation beyond the range of test speeds. The device used for starting up the dynamometer is then disconnected: the rotational speed of the driven roller decreases.

         The kinetic energy of the rollers is dissipated by the power-absorption unit and by the frictional effects. This method disregards variations in the roller's internal frictional effects caused by rollers with or without the vehicle. The frictional effects of the rear roller shall be disregarded when the roller is free.

         2.2. Calibration of the load indicator to 80 km/h as a function of the load absorbed.

         The following procedure shall be used (see also Figure 2/1):

         2.2.1. Measure the rotational speed of the roller if this has not already been done. A fifth wheel, a revolution counter or some other method may be used.

         2.2.2. Place the vehicle on the dynamometer or devise some other method of starting-up the dynamometer.

         2.2.3. Use the flywheel or any other system of inertia simulation for the particular inertia class to be used.

Figure 2/1

Diagram illustrating the power absorbed by the chassis dynamometer

 = F