new wheel design

[mechanicalbrain]

(i dont know if i posted the image correctly or not but i hope it shows if not it looks like an X with omniwheels on each end connected by chain to an outer center shaft and an inner shaft connected directly to the X)
hey im looking for advice. it was one in the morning and this idea hit me and i had to draw it. the little wheels are omniwheels and are rotated by the outer shaft and are connected to the outer shaft by bike chain. this would hapen during normal movement giving the robot a smooth motion. when the inner shaft is rotated it rotates the whole assembly rotates allowing it to
overcome heavy obstacles like stairs with no sweat. the rotation betwean inner and outer shaft would be switched by a gearbox. this means one motor can control each assembly. my only real concern is weight. i would have to experiment with making as much as possible out of plastics. any comments or ideas. note this design would kick $@#$@#$@# on stairs and other rugged terrain.