Page 49 - TBIS_15194-2019_(EN)_3nd

TBIS 15194:2019

4.3.6.4 Handlebar stem to fork steerer – Clamping requirements

The distance g, see Figure 11, between the top of the handlebar stem and the top of
the fork steerer to which the handlebar stem is clamped shall not be greater than 5
mm.

The upper part of the fork steerer to which the handlebar stem is clamped shall not
be threaded.

The dimension g shall also ensure that the proper adjustment of the steering system
can be achieved.

For aluminium and composite fork steerer the avoidance of any internal device that
could damage the internal surface of the fork steerer is recommended.

g Distance between the upper, clamping part of the handlebar stem and the upper, part of
the fork steerer
1 Handlebar stem
2 Extended fork steerer
3 Spacer-rings
4 Head set
5 Head-tube

Figure 11 — Clamping between the handlebar stem and fork steerer

4.3.6.5 Steering stability

The steering shall be free to turn through at least 60° either side of the
straight-ahead position and shall exhibit no tight spots, stiffness or slackness in the

bearings when correctly adjusted.

A minimum of 25 % of the total mass of EPAC and rider shall act on the front wheel

when the rider is holding the handlebar grips and sitting on the saddle, with the
saddle and rider in their most rearward positions.

NOTE Recommendations for steering geometry are given in Annex D.

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