Released in March 1953, the Diamond Free proved
hugely popular, with its double-sprocket wheel mechanism for avoiding power
loss. With 2-speed transmission and output of a mere 2ps at 4,000rpm, it had a
maximum speed of 60km/h. The combined effect of victory in the Mt. Fuji hill
climb race and the machine's showing in across-Japan performance testing led to
an explosion in demand. The displacement was subsequently increased from 60cc to
70cc.
Any corrections or more information on these motorcycles will be kindly appreciated.