AJSModel D 1912 - 1919

　　The model D, with a displacement of 698cc, first appeared in 1912, being the first from the AJS big twins line that ended with a huge machine of 1000cc, manufactured in 1930. This bike was equipped with all-chain drive and a three speed gearbox. The first engines had detachable cylinder heads but in 1913 integral heads were introduced because there were complaints of some leakage. In three years, the capacity of the machine increased to 748cc.