Abstract: A front derailleur for a bicycle pivotally couples a base member fixed to the frame of the bicycle, two linkage members, and a movable member having a chain guide mounted thereon which together constitute a four-connected component linkage mechanism. When a bicycle speed change is made, the movable member moves relative to the base member such that the chain guide component swingingly moves with the amount of movement of the chain guiding portion of the chain guide being larger than the amount of movement of the movable member.

Abstract: A speed-changing device for a bicycle, comprising a derailleur, a control lever and a transmitting device formed of an outer cable and a less flexible inner wire. One end of the outer cable is fixed to the derailleur and the other end is fixed to the control lever. The lever is reciprocally operable to push or pull the inner wire for allowing a movable member of the derailleur to be reciprocated, whereby a single wire can, without a return spring, lightly effect the bicycle's speed change.

Abstract: A speed control device for a bicycle, in which a base member is fixed to the upper portion of a handle stem, a mounting member having a rising higher than the upper surface of the handle stem is fixed to the base member, and a speed control lever is pivoted to the rising of the mounting member.

Abstract: Sprockets for a bicycle are disclosed which comprise sprocket bodies and a plurality of teeth circumferentially provided at the outer peripheries of the bodies respectively, at least one of the teeth on a sprocket body being slanted at its tip with respect to the center line of axial thickness of the sprocket body.

Abstract: A drive for a bicycle provided on the side of its pedals with a freewheel of two or more front chain sprockets, in which the rotational resistance of a rear multiple freewheel in its free rotation is larger than that of the front freewheel in its free rotation so that a driving chain may, even when pedalling is stopped in running of the bicycle, travel across both the front and rear freewheels for changing speed. The drive utilizes a force F.sub.1 of an energizing spring for a chain guide cage of a rear derailleur which is respectively larger than a resistance F.sub.2 applied to the chain in speed change by a front derailleur, and a rotational resistance F.sub.3 of the rear freewheel.

Abstract: A derailleur for a bicycle, which comprises a base member, a movable member and two linkage members carrying the movable member therewith in the relation of being swingingly movable with respect to the base member, a control member swinging independently from the movable member, a pair of plates for energy-storing, which sandwich therebetween one of the linkage members and cooperate with the control member through an engageable projection thereof and a positioning and maintaining member provided between the control member and one of the base member, movable member and two linkage members for positioning the driving chain guide cages with respect to any one of a plurality of sprockets whereby the speed change stage can preliminarily be selected when the bicycle is at a standstill or while running when not pedalling.

Abstract: A rear gear for a bicycle, in which a driving member having two or more sprockets is supported rotatably and axially movably with respect to a driven member. Clutch mechanisms are provided at the axially opposite surfaces between the driving and the driven members so that the driving member may be axially moved to cooperate with the driven member through the connection of each of the clutch mechanisms, thereby permitting rotation of the driving and driven members together.

Abstract: A derailer for a bicycle, comprising a fitting member, a movable member, and a connecting member for movably connecting the movable member with the fitting member, at least one control member swingable independently of the movable member, a spring energized by the swing of the control member, and a positioning device provided between the control member and one of the fitting member, movable member and connecting member and serving to positionally set a chain guide on the movable member with respect to one of a plurality of sprockets, so that the speed-changing stage previously desired may be selected when the pedals stop rotating regardless of whether the bicycle is at a standstill or coasting.

Abstract: A driving chain for a bicycle, which serves to transmit the driving force by pedalling from front chain sprockets to rear chain sprockets, in which each of the outer link plates is partially expanded to the extent that each pin connecting outer link plates with inner link plates respectively comes out of the outside of the outer link plate, so that each of the expanded portions, when the driving chain is shifted by a derailleur, may be in contact with teeth of the sprockets.

Abstract: A multi-speed freewheel for a bicycle, whose outer assembly is formed in a cylindrical shape and a plurality of sprockets to be attached to the outer assembly are previously integrated into a sprocket-block so that the sprocket-block may be detachably mounted on the outer periphery of the outer assembly.

Abstract: A derailleur for a bicycle, having four members which include a fitting member, two parallel linkage members and a movable member, among which four members two opposite members comprise one member pivotally supporting a cam plate in swingable relation and another member provided with a pin engageable with the cam face of the cam plate in swinging the cam plate by a pull of a control wire in changing the bicycle speed so that engagement of the cam plate with the pin defines the speed change stage position.

Abstract: In a derailleur for a bicycle, improved pivotal connections between a bracket fixed to a bicycle frame and a support mounted to the bracket and rotatable only in a given range, and between a movable member supported on the support through links and a chain-change-over frame carried with the movable member through swinging motion only in a given range. At least one of the bracket and the support and one of the movable member and the chain-change-over frame is integrally formed in projection by a press a pivot or a receptor receiving the pivot therein, thereby to provide a derailleur having a reduced number of parts for pivotting and saving processes in assembly with attendant low costs of manufacture.

Abstract: A derailleur for a bicycle, which comprises four members, including a fitting member, two linkage members and a movable member, all movable with respect to each other. Between two of the members there is a device for positioning cages having chain-guide pulleys mounted on the movable member, whereby the derailleur enables the cages to be properly positioned and kept in the position at each speed-change stage of the bicycle so that an accurate and light speed-change operation may be performed.

Abstract: A derailleur for a bicycle, having a fitting member movably supporting a support carrying chain-guide pulleys through two parallel linkage members, is provided with a guard for the support and the linkage members, which guard is formed of an extension of the fitting member directed towards the support, thereby preventing the change-speed mechanism of the derailleur from being damaged when the bicycle is overturned.