Patent ID: 7740565

Claim:
A driving and resistance device for stationary bikes, comprising: a frame including two boards and a shaft extending through the two boards, two cranks connected to two ends of the shaft; a flywheel connected to the shaft, and a driving unit including a driving wheel mounted to the shaft and driving the flywheel, the driving unit further including a first belt, a second belt, an idle wheel unit, an intermediate wheel unit and a passive wheel, the passive wheel connected to a sleeve which is secured to the shaft in a first direction, the driving wheel being driven by rotating the cranks and the first belt, the intermediate wheel unit, the second belt, the passive wheel and the sleeve and the flywheel being driven in sequence; wherein the idle wheel unit includes two adjustment rods, two idle wheels and two side rods, the two adjustment rods extend through two extensions extending from the two boards and are connected to the two idle wheels, the two idle wheels include two axes which movably extend through slots defined through the two boards and the two axes are connected to the two adjustment rods respectively.