Abstract: A speed change operation assembly is provided which requires only a small mounting space and is unlikely to interfere with a brake lever assembly and the like even if mounted near a grip portion of a handlebar. The speed change operation assembly (1) comprises an annular lever mount (5) fixedly fitted on a handlebar (2), and a generally C-shaped lever member (6) elastically fitted on the lever mount for pivotal operation about an axis of the handlebar. The lever mount is integrally formed, on its outer circumference, with a sheath stopper portion (11) for attachment to an end of an outer sheath (w2) of a speed control cable (W) which additionally includes an inner wire (w]) inserted in the outer sheath. On the other hand, the lever member is integrally formed, on its outer circumference, with a wire stopper portion (14) for attachment to an end of the inner wire extending beyond the end of the outer sheath as well as with operating arm portions (15a, 5b) for engagement with the fingers of a rider.

Abstract: The following technical measure is taken to provide a bicycle speed change system or method wherein a speed change operation can be performed substantially without unhanding a handlebar and without erroneously shifting to a lower or higher speed.Specifically, the bicycle speed change system (1) comprises a front speed shifter (1a), a rear speed shifter (1b), and speed change operation assemblies respectively including cylindrical operation members (4a, 4b) rotatably supported around right and left grip portions (3a, 3b), respectively, of a handlebar (2); each of the shifters being operated by a control cable (T) which is pulled or released by rotating a corresponding one of the cylindrical operation members, wherein each of the cylindrical operation members (4a, 4b) is designed so that rotation thereof in a direction of moving its top surface rearward causes a corresponding one of the shifters (1a, 1b) to shift to a lower speed position.

Abstract: The following technical measure is taken to provide a bicycle speed change system or method wherein a speed change operation can be performed substantially without unhanding a handlebar and without erroneously shifting to a lower or higher speed.Specifically, the bicycle speed change system (1) comprises a front speed shifter (1a), a rear speed shifter (1b), and speed change operation assemblies respectively including cylindrical operation members (4a, 4b) rotatably supported around right and left grip portions (3a, 3b), respectively, of a handlebar (2); each of the shifters being operated by a control cable (T) which is pulled or released by rotating a corresponding one of the cylindrical operation members, wherein each of the cylindrical operation members (4a, 4b) is designed so that rotation thereof in a direction of moving its top surface rearward causes a corresponding one of the shifters (1a, 1b) to shift to a lower speed position.

Abstract: The following technical means is provided to achieve a chain shift operation with a minimum of the guide pulley travel distance, to improve speed change efficiency and operatability, and to prevent the speed change assembly from protruding sideward:At a forward location of a sprocket cluster (2), a link base (8) of a pantograph link mechanism (12) is supported by a chain stay (7), and from this, an inner link (9) and an outer link (10) are extended. To respective free end portions of these links, there is connected a movable member (11), which pivotally supports a chain guide (15) which is elastically urged. The guide pulley travel control means (18) functions in such a way that when the pantograph link mechanism (12) is deformed, it would cause a guide pulley (13) of the chain guide (15) to move inward axially of the hub shaft and at the same time forwardly downward substantially along a radial path of the sprocket cluster (2).

Abstract: There is provided a bicycle rear derailleur wherein a problem that shifting the chain to a diametrically larger sprocket causes the guide pulley to come too close to the sprocket, which is an inherent problem to a conventional bicycle rear derailleur using a double tension mechanism, is rationally solved with further improved speed change efficiency. This rear derailleur comprises a rearwardly extending control mechanism (23) pivotally supported at a front end portion thereof to a bicycle frame (22) ahead of the multiple sprocket assembly, the control mechanism mounted at a rear end portion thereof with a chain guide (25) rotatably supporting a guide pulley (39) and a tension pulley (40), wherein the control mechanism is urged against the bicycle frame in a clockwise direction about a first lateral shaft (34), and the chain guide is urged against a chain guide mount of the control mechanism in a clockwise direction about a second lateral shaft (41).

Abstract: For the purpose of providing a bicycle speed change operation assembly capable of ensuring stable handlebar operation and immediate braking operation as well as remarkably improved riding safety during the speed change operation, the following technical means are provided: A bicycle speed change operation assembly according to the present invention comprises a cylindrical operation member (11) rotatably supported around a grip end portion of a handlebar (3), a speed change operation mechanism (12) provided in proximity of that grip end portion of the handlebar (3) and capable of winding and unwinding a speed control cable, and a transmission mechanism (13) provided between the cylindrical operation member (11) and the speed change operation mechanism (12) for driving this speed change operation mechanism (12) in response to the rotation of the cylindrical operation member (11), wherein the speed change operation mechanism (12) functions to wind or unwind the control cable in response to rotational reciprocati

Abstract: The present invention provides a bicycle front derailleur comprising: a movable member including an inner and outer guide plates opposed to each other to define a guide space through which a chain runs; the movable member being moved laterally of a bicycle for shifting the chain. For a purpose of preventing the chain from being caught or damaged by a chain entering edge of the movable member, a following techincal measure is employed: The movable member is provided with catch preventive measure for preventing the chain from being caught by the cain entering edge of the movable member when the chain enters the guide space between the inner and outer guide plates.

Abstract: A bicycle speed change lever assembly which includes a lever shift (9) extending downwardly from a mounting bracket (6a) which is attached adjacent an end grip portion of handlebar (1), and a lever pivotally supported on the lever shaft, the lever including a tubular body (7) rotatably fitted on the lever shaft (9), and a control arm (8) extending radially outward from the tubular body (7). The bracket (6a) has a forward extension (6b) so that the lever shaft (9) is arranged forwardly offset relative to an axis of the handlebar (1), and the lever shaft (9) is inclined to have a tip end deviating from a straight line which passes through a base end (9b) of the lever shaft (9) and is perpendicular to the forward extension (6b). This serves a number of purposes, namely to enable speed change operation while gripping the grip portion (2) of the handlebar (1), to enlarge the pivotal range of the control arm (8) to increase the number of speed stages, and to enable smooth pivotal operation of the control arm (8).

Abstract: With an object of decreasing the size and weight of a derailleur and a control lever assembly by decreasing a difference in an elastic returning force between a beginning and ending phases of the pantograph link mechanism's deformation, the following technical is provided: The parallelogram pantograph link mechanism (7) is provided with a first and second pivotal members (12, 13) each having a predetermined length and pivoted to a predetermined position of a different constituent member of the parallelogram pantograph link mechanism (7), and respective ends of the first and second pivotal members (12, 13) are mutually connected by a pin for causing the first and second pivotal members (12, 13) to pivot relatively to the members to which they are respectively pivoted when the parallelogram pantograph link mechanism (7) is deformed; and a return spring (15) is provided between the first or second pivotal member (12 or 13) and a selected one of the constituent members of the parallelogram pantograph (15).

Abstract: The present invention provides a bicycle speed change assembly comprising: a pantogtaph link mechanism including a link base supported on a chain stay ahead of a sprocket cluster mounted on a hub shaft, inner and outer link members each extending rearward, and having a base end pivoted by a connecting pin to the link base, and a movable member pivoted by connecting pins to respective free ends of the inner and outer link members; and a chain guide rotatably supporting a guide pulley and a tension pulley, the chain guide being supported on the movable member of the pantograph mechanism to pivot about an axis in parallel with the hub shaft while being elastically urged to tension a chain.

Abstract: An operating lever assembly is provided for attachment to a bicycle handlebar which itself includes a pair of end grips. The lever assembly comprises a mount bracket fixable to the handlebar, and an operating lever pivotally connected to the mount bracket. The mount bracket is formed with an auxiliary grip which is usable for manual gripping in addition to the handlebar end grips, thereby enabling the rider to selectively assume at least two different riding postures.

Abstract: A bicycle multiple sprocket assembly comprises smaller and larger sprockets for shiftable engagement with a chain. The larger sprocket includes at least one reluctantly disengageable tooth, at least one chain supporting tooth immediately following the reluctantly disengageable tooth with respect to the forward rotational direction of the sprocket assembly, and at least one easily disengageable tooth immediately following the chain supporting teeth. The apex of the chain supporting tooth is wider than those of the other larger sprocket teeth for supporting thereon the chain at the time of shifting from the larger to smaller sprockets.

Abstract: A bicycle multiple sprocket assembly comprises smaller and larger sprockets for shiftable engagement with a chain. The larger sprocket includes first and second easily disengageable chain supporting teeth arranged adjacent to each other, an easily disengageable chain non-supporting tooth immediately following the chain supporting teeth. Each chain supporting tooth has an apex offset away from the smaller sprocket, and a chain supporting portion on its side closer to the smaller sprocket. The entirety of the chain non-supporting tooth is offset away from the smaller sprocket.

Abstract: A bicycle speed change lever assembly comprises a tubular body (7) pivotally supported on a lever shaft (9) which is located inwardly and downwardly relative to an end grip portion (2) of a handlebar (1) and extends downward, and a control arm (8) extending radially outward from the tubular body. The following measure is taken for enabling speed change operation while gripping the grip portion (2) of the handlebar (1), for enlarging the pivotal range of the control arm (8) to increase the number of speed stages, and for enabling smooth pivotal operation of the control arm (8). The control arm (8) has a first operating arm portion (13) which provides a pivotal path immediately under the handlebar (1) or grip portion (2), and a second operating arm portion (14) which provides a pivotal path spaced from the underside of the handlebar (1) or grip portion (2) by a predetermined distance.

Abstract: A bicycle multiple sprocket assembly comprises at least two adjacent sprockets which include a larger sprocket and a smaller sprocket. A chain takes a shifting path extending from a selected furrow of the smaller sprocket toward a selected furrow of the larger sprocket at the time of shifting from the smaller sprocket to the larger sprocket. At least two teeth of the larger sprocket immediately following the selected furrow of the larger sprocket with respect to the forward rotational direction of the sprocket assembly are rendered circumferentially asymmetric. The leading edge of each asymmetric tooth is provided with a support face which is offset rearwardly for supporting the shifting chain adjacent a chain link connection.

Abstract: A bicycle multiple chainwheel is provided which is mounted on a pedal crank for transmitting a rider's pedalling force to a rear gear through a chain. The chainwheel has the following configuration to prevent a chain from being locked to a diametrically larger sprocket or from prematurely disengaging from the larger sprocket before completely shifting to a diametrically smaller sprocket.The larger sprocket has circumferentially asymmetric teeth located in at least one of diametrically opposite angular regions which contain a diametrical line of the larger sprocket extending along crank arms of the pedal crank, each of the asymmetric teeth being offset relative to a corresponding pitch center in the forward rotational direction of the chainwheel in comparison with the other normal teeth of the larger sprocket.

Abstract: The present invention provides a bicycle front derailleur comprising a base member fixed to the seat tube of a bicycle frame, an inner link member, an outer link member, and a movable member having a chain guide, these members being interconnected by pins to form a parallelogrammatic pantographic link mechanism. The link mechanism is biased by a spring so as to return the movable member toward a smallest sprocket of a multiple chainwheel included in a multi-chainwheel assembly, and is deformed against the spring by a cable for a speed change. The cable is connected to the free end of an actuating arm extending from the upper end of the inner link member toward the outer link member to upwardly pull and pivotally move the actuating arm.The actuating arm therefore forms no upward projection beyond the link mechanism, while the cable can be made to extend upward to a shift lever over a shortened distance with a reduced number of bent portions.

Abstract: The present invention provides a bicycle speed change lever assembly comprising a first lever pivotally pressed to wind up a control cable aginst a tension applied thereto, and a second lever pivotally pressed to pivotally return the first lever for paying out the control cable. The lever assembly further comprises an indexing mechanism provided between the first and second levers for holding the first lever at a selected one of stepwise pivotal positions against the cable tension. The indexing mechanism is made to have a skip preventing function for ensuring that the first lever is pivotally returned stepwise.

Abstract: A brake shoe for bicycles having a shoe holder provided with a connecting rod on its back, and a shoe block held at its base portion to the shoe holder. The braking face of the shoe block is formed with a projection serving as a gauge for positioning the braking face at an appropriate angle with the rim surface of the wheel. When the brake shoe is to be attached to a brake arm, the brake shoe is so positioned that two points of the shoe block, i.e., one point of the braking face and the projection, are in contact with the rim surface, and the brake shoe in this state is fixed to the brake arm. The brake shoe thus positioned is operable optimally as contemplated by the designer. When the brake is actuated, the projection is readily collapsed without producing any adverse effect on the braking function and removed early by friction.