Bicycle drive apparatus

Claim 1

A BICYCLE COMPRISING A FRAME, A FRONT WHEEL AND A REAR WHEEL BOTH MOUNTED IN SAID FRAME, SAID FRAME HAVING A HANDLEBAR FOR STEERING SAID BICYCLE AND A SUPPORT MEMBER POSITIONED BETWEEN SAID FRONT AND REAR WHEELS, A HUB DISPOSED IN SAID REAR WHEEL, A MULTIPLE SPEED GEAR MECHANISM DISPOSED WITHIN SAID HUB, A GEAR SHIFT LEVER POSITIONED ON SAID HANDLEBAR, MEANS DISPOSED ON SAID FRAME COMMUNICATING BETWEEN SAID GEAR SHIFT LEVER AND SAID GEAR MECHANISM FOR SHIFTING GEARS THEREIN, A CRANK POSITIONED IN SAID FRAME INTERMEDIATE SAID FRONT AND REAR WHEELS, A DOUBLE SPROCKET WHEEL MOUNTED ON SAID CRANK AND COMPRISING A FIRST SPROCKET WHEEL AND A SECOND SPROCKET WHEEL DISPOSED IN SIDE BY SIDE RELATIONSHIP, SAID FIRST SPROCKET WHEEL HAVING A SMALLER DIAMETER THAN AND ARRANGED CONCENTRICALLY WITH SAID SECOND SPROCKET WHEEL, A REAR SPROCKET WHEEL MOUNTED ON THE HUB OF SAID REAR WHEEL, AN ENDLESS CHAIN ARRANGED TO ENGAGE AND PASS OVER SAID REAR SPROCKET WHEEL AND ALTERNATIVELY ONE OF SAID FIRST AND SECOND SPROCKET WHEELS, MEANS MOUNTED ON SAID FRAME AND BIASED AGAINST SAID CHAIN TO MAINTAIN TENSION THEREIN, A MOVABLY POSITIONABLE LEVER ARM PIVOTALLY MOUNTED AT APPROXIMATELY ITS MID-POINT ON THE SUPPORT MEMBER OF SAID FRAME, AND MEANS ATTACHED TO THE LOWER END OF SAID LEVER ARM AND IN COMMUNICATION WITH SAID CHAIN WHEREIN BY SELECTIVELY POSITIONING SAID LEVER ARM SAID CHAIN CAN BE ALTERNATIVELY DISPOSED ON SAID FIRST AND SECOND SPROCKET WHEELS.