Page 15 - 20190101 part 6 (EN)

TBIS 4210-6:2019

4.3.2 Test method
4.3.2.1 Stage 1

Use a new frame/fork assembly fitted with standard head tube bearings for the test. The front fork can
be replaced by a dummy fork (see Annex A) of the same length and at least the same stiffness as the
original fork.

NOTE If a genuine fork is used, failures of the fork are possible; therefore, it is recommended that for
convenience, a dummy fork stiffer and stronger than the genuine fork be used.

Where a frame is convertible for male and female riders by the removal of a bar, test it with the bar
removed.

Mount the frame assembly on a base as shown in Figure 3 with the fork or dummy fork secured by its
axle to a rigid mount of height R w (the radius of the wheel/tyre assembly ±30 mm) and with the hub free
to swivel on the axle. Secure the rear dropouts by means of the axle to a stiff, vertical link of the same
height as that of the front, rigid mount, the upper connection of the link being free to swivel about the
axis of the axle but providing rigidity in a lateral plane, and the lower end of the link being fitted with a
ball-joint.

Fit a crank, chain wheel and chain assembly or, preferably, a strong, stiff, replacement assembly to the
bottom bracket as shown in Figure 3 and described in item a) or b) below.

a) If a crank/chain-wheel assembly is used, incline both cranks forwards and downwards at an angle
of 45° (accurate to within ±2,0°) to the horizontal and secure the front end of the chain to the middle
chain wheel of three, the smaller chain wheel of two, or the only chain wheel. Attach the rear end of
the chain to the rear axle and perpendicular to the axis of the axle.

b) If an adaptor assembly is used (as shown in Figure 3), ensure that the assembly is free to swivel
about the axis of the bottom-bracket and that both replacement arms are 175 mm long (L) and that
they are both inclined forwards and downwards at an angle of 45° (accurate to within ±2,0°) to the
horizontal. Secure the position of the crank replacement arms by a vertical arm (which replaces the
chain wheel) and a tie rod which has ball joints at both ends and which is attached to the rear axle
perpendicular to the axis of the rear axle. The length of the vertical arm (R c) shall be 75 mm and the
axis of the tie rod shall be parallel to and 50 mm from the vertical plane through the centreline of
the frame.

Subject each pedal spindle (or equivalent adaptor component) to a repeated downward force of F 1 at
a position 150 mm from the centreline of the frame in a vertical, transverse plane and inclined at 7,5°
(accurate to within ±0,5°) to the fore/aft plane of the frame as shown in Ta ble 3 and Figure 3. During
application of these test forces, ensure that the force on a “pedal spindle” falls to 5 % or less of the peak
force before commencing application of the test force to the other “pedal spindle”.

Apply the test forces for 120 000 test cycles, where one test cycle consists of the application and removal
of the two test forces. The maximum test frequency shall be maintained as specified in TBIS 4210-
3:2014, 4.5.
If the frame meets the requirement as specified in TBIS 4210-2:2017, 4.8.4, and conduct stage 2 of the
test with the assembly in the same mountings.

4.3.2.2 Stage 2
With the frame and front fork assembly mounted as in 4.3.2.1. Apply a repeated downward
force of Stage 2 F1 as shown in Tab. 3 for 100 000 test cycles, where one test cycle consists of the
application and removal of the two test forces. The maximum test frequency shall be maintained as
specified in TBIS 4210-3:2016, 4.5.
Table 3 — Forces on pedal spindle

Forces in newtons

City and trekking
Bicycle type bicycles Young adult bicycles Mountain bicycles Racing bicycles

Stage 1 F1 1 000 1 000 1 200 1 100
Stage 2 F1 1100 1100 1300 1200

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