The present invention relates to a disk apparatus which is detachably attached to an existing wheel, and which generates electricity that provides the driving force to move the wheel. More specifically, the disk apparatus comprises: a fixed plate attached ...

Disclosed is a bicycle which is a means of short-distance movement favored by men and women of all ages. The present invention is an application of a bicycle having a motor-generator disclosed in Korean Patent Application No. 2009-035298 that the applicant...