Page 31 - 2017-v.2-Part 4(EN)

Recorded operating force F Op rec = 184 N

Correction factor = 180/184
Corrected braking force F Br corr = 225 × (180/184)

e) Test results

Select from the record the maximum output braking force, F Br max, for each combination of wheel
(front or rear) and each test condition (wet or dry).

The braking performance value shall be calculated using Formula (3):

m
B = F Br max × (3)
p
M

where

B p is the braking performance value (N);

F Br max is the maximum F Br average (N);

m is the standard mass of the bicycle defined as 100 kg for adult bicycle and 60 kg for
young adult bicycle (kg);

M is the maximum permissible total mass specified by the manufacturer in TBIS 4210-2,
Clause 5 item h) (kg).

Where a manufacturer specifies that his bicycle can carry a mass such that the sum of that mass
plus the mass of the bicycle is in excess of 100 kg (60 kg for young adults) to some value M, apply M
as total weight.

f) Linearity

Plot the calculated F Br average values (the arithmetic mean of the three corrected braking forces at
each level of operating force) against the equivalent operating force values, F Op intend, in order to
assess the linearity against the requirement in 4.6.5.3. Plot the results on a graph, showing the line
of best fit and the ±10 % for mountain and racing bicycle, others are ±20 % limit lines obtained by
the method of least squares outlined in Annex A.

g) Ratio between wet and dry braking for city and trekking, young adult, and mountain bicycles, and
racing bicycle in disc brake system

D
For any operating force (F Op) for which the measured dry braking force (F Br average) is greater
than 200 N, the ratio between the measured braking force in wet conditions (F W Br average) and the
D
measured braking force in dry conditions (F Br average) shall be greater than 50 %.

For each F Op where F Br average is > 200 N, determine] whether or not the requirements of have been
D
met using Formula (4):

F W Br average: F Br average (4)
D

For symbols see 4.6.5.2.

h) Simple track test (see TBIS 4210-2:2017, 4.19)

After completion of the machine test, conduct a brief, simple track test with progressively increasing
operating forces to determine whether or not the brakes bring the bicycle to a smooth, safe stop.

NOTE This test can be combined with the test on the fully assembled bicycle.

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