Document ID: chunk:federal_register_of_legislation:F2021C00509:front:0:p52
Version: federal_register_of_legislation:F2021C00509
Segment Type: other
Provision Reference: 
Character Range: 149890–153063

placed in those parts of the silencer through which the exhaust gases pass and must comply with the following requirements:

           1.2.1.                                        The material must be heated at a temperature of 650 +/- 5 degrees C for four hours in a furnace without reduction in every length, diameter or bulk density of the fibre.

           1.2.2.                                        After heating at 650 +/- 5 degrees C for one hour in a furnace, at least 98% of the material must be retained in a sieve of nominal aperture size 250 mu m complying with ISO Standard 3310/1 : 1990 when tested in accordance with ISO Standard 2599 : 1983.

           1.2.3.                                        The loss in weight of the material must not exceed 10.5% after soaking for 24 hours at 90 +/- 5 degrees C in a synthetic condensate of the following composition:
           1 N hydrobromic acid (HBr): 10 ml
           1 N sulphuric acid (H2SO4): 10 ml
           Distilled water to make up to 1,000 ml.
           Note: The material must be washed in distilled water and dried for one hour at 105 degrees C before weighing.

           1.3.                                              Before the system is tested in accordance with annex 3, it must be put into a normal state for road use by one of the following condition methods:

    1.3.1.                                        CONDITIONING BY CONTINUOUS ROAD OPERATION

           1.3.1.1.                                  According to the classes of motor cycles, the minimum distances to be completed during conditioning are:

Class of motor cycle                   Distance (km)
according to cylinder capacity in cm3
    Class I  < 80                      4,000
    Class II > 80 < 175                6,000
    Class III  > 175                   8,000

           1.3.1.2.                                  50 +/- 10% of this conditioning cycle consists of town driving and the remainder of long- distance runs at high speed; the continuous road cycle may be replaced by a corresponding test-track programme.

    1.3.1.3.                                  The two speed regimes must be alternated at least six times.

           1.3.1.4.                                  The complete test programme must include a minimum of 10 breaks of at least three hours' duration in order to reproduce the effects of cooling and condensation.

           1.3.2. CONDITIONING BY PULSATION

           1.3.2.1. The exhaust system or components thereof must be fitted to the motor cycle or to the engine. In the former case, the motor cycle must be mounted on a test bench.
           The test apparatus, a detailed diagram of which is shown in Figure 1, is fitted at the outlet of the exhaust system. Any other apparatus providing equivalent results is acceptable.

           1.3.2.2. The test equipment must be adjusted so that the flow of exhaust gases is alternatively interrupted and restored 2,500 times by a rapid-action valve.

           1.3.2.3. The valve must open when the exhaust gas back-pressure, measured at least 100 mm downstream of the intake flange, reaches a value of between 0.35 and