Page 24 - TBIS_79010-2019_(EN)_1nd

TBIS 79010:2019

high enough to achieve a braking force of 200 N ± 10 %. Maintain this operating
force for at least 2,5 s, and note the value of the applied operating force.

Repeat the procedure (applying the operating force determined as above accurate to
within ± 5 %) 10 times, or, with more repetitions if necessary, until the mean braking
force from anyone of the three latest tests does not deviate by more than ± 10 %

from the mean braking force from these same three tests.
c) The performance tests
1) Testing under dry conditions

For hand operated brakes, with a vertical force applied to the bicycle sufficient to
prevent skidding of the tyre on the wheel under test, accelerate the driving
mechanism to the specified velocity, then apply the operating-force in a series of 20

N increments from 40 N to either 180 N or to the force necessary to achieve a
braking force of at least 700 N, whichever is the lesser. However, if the wheel locks,
if any possible brake-overload device is actuated, or if the hand-lever comes into
contact with the handlebar, do not increase the force further. For each increment of

applied operating force, perform three tests within 1 min. Before applying the next
level of operating force, allow the brake to cool for 1 min.

For back-pedal brakes, with a vertical force applied to the bicycle sufficient to
prevent skidding of the tyre on the wheel under test, accelerate the driving
mechanism to the specified velocity, then apply the operating-force in a series of 50
N increments from 100 N to either 350 N or to the force necessary to achieve a
braking force of at least 400 N, whichever is the lesser. However, if the wheel locks,

if any possible brake-overload device is actuated, do not increase the force further.
For each increment of applied operating force, perform three tests within 1 min.
Before applying the next level of operating force, allow the brake to cool for 1 min.

The applied operating forces shall lie within ± 10 % of the intended operating forces,
shall be applied as specified in Figures 5 and 6 and 4.2.2.9.3.3 c), shall be recorded
with an accuracy of ± 1 %, and shall be fully applied within 1,0 s of the

commencement of braking.
For each increment of operating force, record the braking force value, F Br rec, for a

period of between 2,0 s and 2,5 s, with measurement starting 0,5 s to 1,0 s after the
commencement of braking. Record F Br rec as the average braking force during this
measurement period.

The time at which the measurement of the braking force is started shall be related to
the speed at which the operating force is applied. If the operating force is fully
applied in less than 0,5 s after the commencement of braking, start the
measurement after 0,5 s. However, if the operating force is fully applied between 0,5

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