Abstract: A bicycle gearing system includes input and output shafts, two planetary gear systems, and a clutch mechanism. The clutch mechanism includes three clutch presser plates for frictional engagement with two clutch disks and a clutch base. A motor rotates a camshaft formed with cams selectively engageable with cam followers for driving the clutch presser plates to rotate. Steels balls are provided within cavities formed between the clutch presser plates and a clutch housing to convert rotation of clutch presser plates to linear force for frictional engagement with the two clutch disks and the clutch base. Different angles of rotation of the camshaft produce different clutch and gear combinations and different gear ratios.

Abstract: A bicycle gearing system includes input and output shafts, two planetary gear systems, and a clutch mechanism. The clutch mechanism includes three clutch presser plates for frictional engagement with two clutch disks and a clutch base. A motor rotates a camshaft formed with cams selectively engageable with cam followers for driving the clutch presser plates to rotate. Steels balls are provided within cavities formed between the clutch presser plates and a clutch housing to convert rotation of clutch presser plates to linear force for frictional engagement with the two clutch disks and the clutch base. Different angles of rotation of the camshaft produce different clutch and gear combinations and different gear ratios.

Abstract: A variable transmission gearing system for a bicycle includes a mainboard driven by a chain gear, a plurality of cone gears rotatable on a plurality of shafts fixed on the mainboard respectively, and a sun gear rotatable with an input shaft of a wheel. Also disclosed is a variable transmission gearing system including a sprocket mounted on a sprocket mount, a cone driver rotatable with the sprocket mount, a plurality of cone gears rotatably mounted between the cone driver and a cone holder, a driven pad frictionally engaged and rotatable with the cone gears, a main shaft rotatable with the driven pad, and a shifting shaft frictionally engaged and rotatable with the cone gears.