Page 35 - 2018-v.3-Part 2(EN)
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Dimensions in millimetres
Key
a the point where the chain wheel first passes between the side plates of the chain
b 25 mm rearwards from the point where the chain wheel first passes between the side plates of the chain
Figure 9 — Chain and chain-wheel junction
4.16 Saddles and seat-posts
4.16.1 Limiting dimensions
No part of the saddle, saddle supports, or accessories to the saddle shall be more than 125 mm above the
top saddle surface at the point where the saddle surface is intersected by the seat-post axis.
4.16.2 Seat-post — Insertion-depth mark or positive stop
The seat-post shall be provided with one of the two following alternative means of ensuring a safe
insertion depth into the frame.
a) It shall contain a permanent, transverse mark of length not less than the external diameter or the
major dimension of the cross section of the seat-post that clearly indicates the minimum insertion
depth of the seat-post into the frame. For a circular cross section, the mark shall be located not less
than two diameters of the seat-post from the bottom of the seat-post (i.e. where the diameter is the
external diameter). For a non-circular cross section, the insertion-depth mark shall be located not
less than 65 mm from the bottom of the seat-post (i.e. where the seat-post has its full cross section).
b) It shall incorporate a permanent stop to prevent it from being drawn out of the frame such as to
leave the insertion less than the amount specified in item a) above.
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