Page 14 - 20190101 part 7 (EN)

TBIS 4210-7:2019

Annex A
(informative)

Wheel/tyre assembly — Fatigue test

A.1 Wheel/tyre assembly — Fatigue test for city and trekking bicycles

A.1.1 Requirements

When tested by the method described in A.1.2, there should be no fractures, detachments, or visible
cracks in any part of the wheel, no loss of air pressure in the tyre due to damage from the wheel to the
tyre or the inner tube (when fitted), and the undamaged tyre should remain on the rim, perform the
rotational accuracy described in 4.1. And the requirement is show as below:

The values of permanent deformation after fatigue test
Dimensions in millimetres

City and trek- Young adult Mountain Racing
Bicycle type king bicycles bicycles bicycles bicycles

Permanent 1,2 1,0
deformation

A.1.2 Test method

Assemble the wheel, tyre, and inner tube (when fitted) and inflate the tyre to 90 % of the maximum
inflation pressure.

Mount the wheel/tyre assembly free to rotate on its axle, and free to move in a vertical direction. Load
the wheel assembly by means of dead weights against a drum equipped with equally spaced, transverse,
metallic slats such that the radial force applied to the wheel/tyre assembly is 640 N. The wheel and
drum axes shall be vertically aligned.

An example of a test arrangement is shown in Figure A.1, in which the wheel axle is fixed between the
free ends of a pair of pivoted arms that extend horizontally with the tyre contacting the drum between
the slats.

The diameter of the drum shall be in the range of 500 mm to 1 000 mm, and the slats shall have a width
of 50 mm ± 2,5 mm, a thickness of 10 mm ± 0,25 mm, and 45° chamfered edges of half their thickness.
The circumferential spacing between the centrelines of two consecutive slats shall be not less than
400 mm.

Rotate the drum to give a linear surface speed of 25 km/h (±10 %) for a period to provide 750 000
impacts between the tyre and the slats.

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