Page 73 - TBIS_15194-2019_(EN)_3nd

TBIS 15194:2019

Apply a static, pre-loading force of 100 N to the roller perpendicular to the steerer
axis, against the direction of travel, and in the plane of the wheel. Remove and
repeat this loading until a consistent deflection reading is obtained. Adjust the
deflection measuring device to zero.

Increase the static force to F5 and maintain this force for 1 min, then reduce the
force to 100 N and record any permanent deformation. The forces are given in Table
17.

Table 17 — Forces on loading attachment

Forces, F 5 1 500 N

4.3.8.5 Front fork – Rearward impact test

4.3.8.5.1 Forks made entirely of metal
4.3.8.5.1.1 Crown/steerer joint assembled by welding or brazing

When tested by the method described in 4.3.8.5.3, there shall be no fractures or
visible cracks in any part of the fork, and the permanent deformation, measured as

the displacement of the axis of the wheel-axle or simulated axle in relation to the
axis of the fork steerer, shall not exceed 45 mm. If the fork meets these criteria then
it shall be subjected to a second test as described in 4.3.8.5.4 b), after which, it shall
exhibit no fractures, then it shall be subjected to a third test as described in 4.3.8.5.4
c), irrespective of the amount of permanent deformation, there shall be no relative

movement between the steerer and the crown.
If the fork is used in the frame impact test (falling-mass), 4.3.7.2, there is no need to

perform this test.
4.3.8.5.1.2 Crown/steerer joint assembled by press-fitting, bonding, or clamping

When tested by the method described 4.3.8.5.4 a), if there are any fractures or
visible cracks in any part of the fork, and the permanent deformation, measured as
the displacement of the axis of the wheel-axle or simulated axle in relation to the

axis of the fork steerer, exceeds 45 mm, the fork shall be considered to have failed. If
the fork meets these criteria then it shall be subjected to a second test as described
in 4.3.8.5.4 b), after which, it shall exhibit no fractures, then it shall be subjected to a
third test as described in 4.3.8.5.4 c), irrespective of the amount of permanent

deformation, there shall be no relative movement between the steerer and the
crown.

4.3.8.5.2 Forks which have composite parts
When tested by the method described in 4.3.8.5.3, there shall be no fractures in any
part of a fork and the permanent deformation, measured as the displacement of the

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