Page 21 - 2018-v.3-Part 2(EN)

4.7.6.4 Handlebar to handlebar stem — Torsional security test

When tested by the method described in TBIS 4210-5:2016, 4.5, there shall be no movement of
the handlebar relative to the handlebar stem.

4.7.6.5 Handlebar stem to fork steerer — Torsional security test

When tested by the method described in TBIS 4210-5:2016, 4.6, there shall be no movement of the
handlebar stem relative to the fork steerer.

4.7.6.6 Bar end to handlebar — Torsional security test

When tested by the method described in TBIS 4210-5:2016, 4.7, there shall be no movement of the bar end
in relation to the handlebar.

4.7.6.7 Aerodynamic extensions to handlebar — Torsional security test

When a handlebar is suitable for use with aerodynamic extensions, the extension/handlebar/handlebar
stem assembly shall withstand the following security test.

When tested by the method described in TBIS 4210-5:2016, 4.8, there shall be no movement of the
extension in relation to the handlebar and of the handlebar in relation to the handlebar stem.

4.7.7 Handlebar and stem assembly — Fatigue test

4.7.7.1 General

Handlebar stems can influence test failures of handlebars and, for this reason, a handlebar shall always
be tested mounted on a stem, but it is permitted to test a stem with a solid bar in place of the handlebar
and bar ends with dimensions corresponding to handlebars/bar ends suitable for that stem.

When the fatigue test is for the stem only, the manufacturer of the stem shall specify the types and sizes
of handlebar for which the stem is intended and the test shall be based on the most severe combination.

Conduct the test in four stages on the same assembly.

4.7.7.2 Requirement for stage 1, stage 2, stage 3 and stage 4

When tested by the method described in TBIS 4210-5:2016, 4.9.1 or 4.9.2, there shall be no visible cracks
or fractures in any part of the handlebar and stem assembly or any bolt failure.

For composite handlebars or stems, the running displacements (peak-to-peak value) at the points where
the test forces are applied shall not increase by more than 20 % of the initial values.

4.8 Frames

4.8.1 Suspension-frames — Special requirements

The design shall be such that if the spring or damper fails, the tyre shall not contact any part of the frame
or the assembly carrying the rear wheel shall become detached from the rest of the frame.

NOTE See TBIS 4210-6:2017, Annex C.

4.8.2 Frame — Impact test (falling mass)

When tested by the method described in TBIS 4210-6:2017, 4.1, there shall be no visible cracks or
fractures of the frame.

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