Page 71 - TBIS_15194-2019_(EN)_3nd

TBIS 15194:2019
4.3.8 Front fork

4.3.8.1 General

4.3.8.2, 4.3.8.4, 4.3.8.5 and 4.3.8.6 apply to all types of fork.

In the strength tests, 4.3.8.4, 4.3.8.5, 4.3.8.6 and 4.3.8.7, a suspension-fork shall be
tested in its free, uncompressed length condition.

4.3.8.2 Means of location of the axle and wheel retention

The slots or other means of location for the wheel-axle within the front fork shall be
such that when the axle or cones are firmly abutting the top face of the slots, the

front wheel remains central within the fork.

The front fork and wheel shall also fulfil the requirements of 4.3.9.4 and 4.3.9.5.
4.3.8.3 Suspension-forks – Special requirements

4.3.8.3.1 Tyre-clearance test

4.3.8.3.1.1 Requirement

When tested by the method described in 4.3.8.3.1.2, the tyre shall not contact the
crown of the fork nor shall the components separate.

4.3.8.3.1.2 Test method

For the tyre-clearance test, a suspension-fork shall first be checked and adjusted if
necessary according to the items listed in following a) to f):

a) Inflate the tyre to its maximum pressure;

b) Place the fork in uncompressed condition to have the highest displacement
between suspension stanchion legs and suspension lower legs;

c) If the suspension-fork can be locked, place the fork in the open position;

d) If the fork has a spring adjust device, place it in the softest position;

e) If the fork has a pneumatic device, blow up the one or the two chambers at their

minimum pressures according the manufacturer’s instruction;

f) If the fork has a rebound device, place it on the slowest position. With a wheel and
tyre assembly fitted to the fork, apply a force of 2 800 N to the wheel in a direction
towards the fork-crown and parallel to the axis of the fork steerer. Maintain this
force for 1 min.

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