The 356 cam was introduced at the beginning of the A10 in 1951 for the sports models A7ST and Super Flash and the A7SS when introduced in 54. The 334 cam, used on basic models, was dropped at the end of 58 and the 356 was then used on all models whilst the 357 was adopted for the sports models in 61. Thick flange barrels (67-1210) were used by all 650 models from 1958 and by the Sports models from 54. The use of three-bolt crank matched the thick flange cylinder application.