Abstract: A bicycle sprocket set is composed of a small sprocket and a large sprocket coaxial with the small sprocket. The large sprocket is provided with an axially oriented recess in the bottom portion located between the first tooth and the second tooth of the large sprocket. The recess has a support curved face extending from the second tooth. The large sprocket is further provided with a support protrusion located under the support curved face such that the support protrusion is separated from the support curved face by a distance corresponding to about one tooth pitch. The support curved face and the support protrusion serve to support the inner and the outer chain plates of a drive chain at such time when the gearshifting takes place.

Abstract: A self-contained change speed apparatus for use on a bicycle. It has fixed shaft, a hub body rotatably supported on the fixed shaft, a change speed device controlled to turn the hub body about the fixed shaft at one of a series of speeds, and a power input member adapted to provide driving power, A clutch is moved between an active position and a non-active position and adapted to transmit driving power from the power input member to the change speed device. A control mechanism changes the speed ratio of the change speed device, advances the clutch to the non-active position before changing the speed of the change speed device, and delays the movement of the clutch to the active position, for permitting driving power to be returned to the change speed device after a change of the speed ratio of the change speed device.

Abstract: The present invention relates to a speed-changing transmission hub for a bicycle comprising: a central shaft; a controlling device; a planetary gear system, which comprises a planet gear holder, holding several planet gears; a second ring gear; a first ring gear; and two sun gears. Variations of speed are realized by separately fixing the sun gears of different diameters. There is no switching of input and no reversal of the rotation of the sun gears. The sun gears only need to be controlled by a one-way clutch guided by the controlling device, which is mounted on the central shaft. Thereby the arrangement is simplified and its weight is reduced.

Abstract: A multi-speed sprocket assembly of a bicycle includes at least a small sprocket and a large sprocket which enable the chain to engage with different sprockets to attain the chain shifting effect by the guidance of the rear derailleur device. The improvement of the multi-speed sprocket assembly includes three feature teeth being furnished at both the large sprocket and the small sprocket wherein a side recess is formed on each of the feature teeth at the surface of a sprocket facing another sprocket, in addition, at the first and second feature teeth of the small sprocket, there is a circular top end recess extended from the top of the teeth at the surface subjected to forces and penetrated through the circular top end recess of the whole teeth.