The charge carrier mobility along a molecular wire of fluorene-thiophene copolymers represented by poly-(9,9'-di-n-octylfluorene-co-bithiophene): F8T2 is investigated by flash-photolysis time-resolved microwave conductivity. We systematically examined the impacts of the number of oligothiophene units, their composition ratios, and molecular weights. It is revealed that the odd-even number of oligothiophene units has a significant effect on the mobility if they are incorporated into the polyfluorene backbone in high ratio. The structural dependence study and the observed high intramolecular mobility of about 1 cm(2) V-1 s(-1) could be helpful for the design of novel multicomponent conjugated copolymers and its application in organic electronic devices.