Page 67 - TBIS_15194-2019_(EN)_3nd
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TBIS 15194:2019
4.3.7.5 Frame – Fatigue test with horizontal forces
4.3.7.5.1 General
Where a frame is convertible for male and female riders by the removal of a bar,
remove the bar.
It is not necessary for a genuine fork to be fitted, provided that any substitute fork is
of the same length as the intended fork (see Annex F) and it is correctly installed in
the steering-head bearings. For a suspension fork, lock it at a length equivalent to
that with an 90 kg rider seated on the bicycle either by adjusting the spring/damper
or by external means. (In case of young adult bicycles, apply 40 kg)
In tests on suspension frames with pivoted joints, lock the moving part of the frame
into a position as would occur with a 90 kg rider seated on the bicycle. This may be
achieved by locking the suspension unit in an appropriate position or, if the type of
suspension system does not permit it to be locked, then the suspension system may
be replaced by a solid link of the appropriate compressed size. Ensure that the axes
of the front and rear axles are horizontally in line, as shown in Figure 22. For
suspension-frames in which the chain-stays do not have pivots but rely on flexing,
ensure that any dampers are set to provide the minimum resistance in order to
ensure adequate testing of the frame.
Where a suspension frame has adjustable brackets or linkages to vary the resistance
of the bicycle against the ground-contact forces or to vary the attitude of the bicycle,
arrange the positions of these adjustable components to ensure maximum forces in
the frame.
4.3.7.5.2 Requirement
When tested by the method described in 4.3.7.5.3, there shall be no visible cracks or
fractures in the frame and there shall be no separation of any parts of any
suspension system.
For composite frames, the running displacement (peak-to-peak value) at the point
where the test forces are applied shall not increase by more than 20 % of the initial
values (see 4.3.1.6).
4.3.7.5.3 Test method
4.3.7.5.3.1 Stage 1 Frame – Fatigue test with horizontal forces
Mount the frame in its normal attitude and secured at the rear drop-outs so that it is
not restrained in a rotary sense (i.e. preferably by the rear axle) as shown in Figure
22. Ensure that the axes of the front and rear axles are horizontally in line.
Apply cycles of dynamic, horizontal forces of F2 in a forward direction and F3 in a
rearward direction to the front fork drop-outs for C1 cycles as shown in Table 15 and
Figure 22, with the front fork constrained in vertical direction but free to move in a
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