Abstract: A free wheel rotary body structure for use in a bicycle is disclosed. It includes a free wheel kernel having a pair of axially extending ratchet pawl bearings at diametrically opposite positions relative to each other and a pair of ring grooves. The rotary body structure also includes first and second sets of one-way clutches. Each of the one-way clutches includes a c-spring and a pair of ratchet pawls. The pair of c-springs are received in the pair of ring grooves, respectively, of the free wheel kernel, and the pairs of ratchet pawls are received in the diametrically opposing pawl bearings, respectively, of the free wheel kernel. The pair of ratchet pawls in the first set of one-way clutch are of different shapes and dimensions from the pair of ratchet pawls in the second set of one-way clutch, so as to form phase difference when one of each pair of the ratchet pawls is engaged with the ratchet teeth groove of the free wheel housing.

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 bicycle speed changing apparatus comprises a support means, a cable winding means, a fixation plate, a high gear shifting means, a retaining mechanism, a low gear shifting means, and a transmission mechanism. The support means is fastened with the handlebar of a bicycle. The low gear shifting means has a low turning rod connected with the support means by a first retrieving spring and provided with a first braking portion. The cable winding means is connected with the support means by a torsion spring. The fixation plate is provided with a second braking portion. The high gear shifting means has a high turning rod fastened with the fixation plate by a second retrieving spring. The retaining mechanism has a shaft fastened pivotally with the support means and the fixation plate. The shaft is provided with an engaging means and a first cam, a first ratchet portion and a third braking portion.

Abstract: A multiple sprocket assembly for use in a bicycle comprising: (1) at least a large sprocket wheel and a small sprocket wheel, each of the large and small sprocket wheels having a plurality of teeth on an outer edge thereof, and the large sprocket wheel having more teeth than the small sprocket wheel; (2) each of the sprocket wheels being adapted to engage with a chain guided by a derailleur; the chain comprising a plurality of rollers connected in series by link plates. The multiple sprocket assembly is characterized in that the small sprocket wheel has at least two consecutive teeth, each with a portion of its side surface trimmed off, and the large sprocket wheel has at least three consecutive teeth each also with a portion of its side surface trimmed off, so as to avoid interference between the link plates and the large sprocket when the chain is being shifted from the small sprocket to the large sprocket.