Sigma BC 509 Manual Del Usuario página 14

5.2 Wheel size chart (Radgröße / Wheel size / Circonference de Roue)
A
B
14
mm x 3,14
1x
km/h:
WS = mm x 3,14
mph:
WS = mm x 3,14
km/h:
WS = mm
mph:
WS = mm
= WS (mm)