OK 1919 HO Twin Crankshaft
L. The crankshaft assembly of the 2¾ h.p. O.K., showing the roller bearings on the mainshaft, the half-time pinion, and the split big ends.
R. The novel timing gear. The cams are formed on an internally cut gear wheel, to which also the magneto chain sprocket is fixed.Credit: The Motor Cycle