AJS 18CS Competition

.The 500 cc "long stroke" AJS 18CS was produced from 1951 through 1955. In 1956 it was replaced by the shorter stroke, larger bore models that used the same numeric codes. The bore of these early models was 82.5 mm (3.25 in), while the 1956 through 1966 "short stroke" (final version) models had a bore of 86 mm (3.39 in). The C was for Competition (Scrambles) and the S for Suspension (not a rigid