innovation continues - for example,there is considerable interest in recumbent bicycles where the rider lies down on a lower-level cycle,which is more efficient in terms of energy transmission and aerodynamics;the resulting design is capable of speeds in excess of 40km /hour. Motorizing cycles with various kinds of electric devices has been tried notably with the ill-fated Sinclair C5 althought unsuccessful the concept of electric motor assistance to pedal power has led to the relatively successful Zeke device. But the pattern appears to have stabilized again into a transitional/mature phase with emphasis on product differentiation of an incremental nature in specialized market niches,and in process innovation towards cost reduction