Document ID: chunk:federal_register_of_legislation:F2021C01192:body:0:p39
Version: federal_register_of_legislation:F2021C01192
Segment Type: other
Provision Reference: 
Character Range: 104700–107425

inspection authority shall verify conformity with the requirements contained in the present annex, by carrying out the following tests:
5.1. Wheel-lock sequence test (see Appendix 1)
 If the wheel-lock sequence test confirms that the front wheels lock before or simultaneously with the rear wheels, conformity with paragraph 3. of this annex has been verified and testing is complete.
5.2. Additional tests
 If the wheel-lock sequence test indicates that the rear wheels lock before the front wheels, then the vehicle:
(a) Will be subjected to additional testing, as follows:
(i) Additional wheel-lock sequence tests; and/or
(ii) Torque wheel tests (see Appendix 2) to determine brake factors To generate adhesion utilization curves; these curves shall satisfy the requirements in paragraph 3.1.(A) of this annex.
 (b) May be refused type-approval.
5.3. The results of the practical tests shall be appended to the type-approval report.
6.  Conformity of production
6.1. When checking vehicles for conformity of production, the Technical Services should follow the same procedures as for type-approval.
6.2. The requirements shall also be the same as for type-approval, except that in the test described in paragraph 5.2.(a)(ii) of this annex, the rear axle curve shall lie below the line z = 0.9 k for all braking rates between 0.15 and 0.8 (instead of meeting the requirement in paragraph 3.1.(A) (see diagram 2).
  Diagram 1

  Diagram 2
Annex 5 - Appendix 1
  Wheel-lock sequence test procedure
1. General information
(a) The purpose of this test is to ensure that lockup of both front wheels occurs at a lower deceleration rate than the lockup of both rear wheels when tested on road surfaces on which wheel lockup occurs at braking rates between 0.15 and 0.8.
(b) A simultaneous lockup of the front and rear wheels refers to the condition when the time interval between the lockup of the last (second) wheel on the rear axle and the last (second) wheel on the front axle is  0.1 seconds for vehicle speeds  30 km/h.
2.  Vehicle conditions
(a) Vehicle load:  Laden and unladen
(b) Transmission position:  Engine disconnected
3. Test conditions and procedures
(a) Initial brake temperature:  Between 65 °C and 100 °C average on the hottest axle.
(b) Test speed:   65 km/h for a braking rate  0.50;
    100 km/h for a braking rate  0.50.
(c) Pedal force:
(i) Pedal force is applied and controlled by a skilled driver or by a mechanical brake pedal actuator.
(ii) Pedal force is increased at a linear rate such that the first axle lockup occurs no less than one-half (0.5) second and no more than one and one-half (1.5) seconds after the initial application of the pedal.
(iii) The pedal is released when the second axle