Binary solid solution alloys that show class A alloy (CAA) behaviour with low stress exponents, absence of substructure and reduced normal or inverted primary creep are analysed. These characteristics are referred to as the class A state (CAS). Basic dislocation climb based models are used to compute properties of Al-Mg and Al-Zn alloys. It is demonstrated that a single climb based model can accurately represent the creep strain rate versus stress. It is no longer necessary to consider a transition from climb to glide and back to climb again. The absence of substructure in CAS is allotted to the recovery of screw dislocations by cross-slip. An expression for the rate of this type of recovery is derived. The presence of inverted primary creep is believed to be due to a significant initial dislocation density. This is consistent with simulated primary creep curves.