Compact vehicle drive mechanisms are provided. These compact drive mechanisms, for example, have contributed to the advent of the compact, carry-on bicycles set-forth in the teachings.

A chainring includes a first section having consecutive first teeth. Each of the first teeth includes a first load flank surface having a first wear resistance. The chainring also includes a second section coupled to the first section. The second section includes consecutive second teeth. Each of the second teeth includes a second load flank surface having a second wear resistance greater than the first wear resistance. The consecutive second teeth span an arc length corresponding to between one twelfth and one third of a circumference of a pitch circle of the chainring.

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

A chain for a bicycle, a sprocket cassette, a chainring, a crankset, a chain drive system, and a bicycle are provided. The chain comprises a plurality of interleaved link elements, each link element being pivotably attached to at least one other link element and comprising at least two teeth. A flank of each tooth is adapted to engage with a flank of a sprocket tooth. The sprocket cassette comprises one or more sprockets, each comprising a plurality of sprocket teeth, wherein each sprocket tooth has a flank with a profile corresponding to a profile of at least part of a tooth of each of the plurality of link elements. The chainring comprises a plurality of sprocket drive teeth having a profile corresponding to the profile of at least one of the teeth of each of the plurality of link elements.

An apparatus for driving a drive chain, such as on a bicycle, may include a chainring having teeth arranged around a circumference of the chainring, and one or more magnetic portions disposed adjacent to the teeth of the chainring. The one or more magnetic portions may be disposed on the chainring and/or on a frame to which the chainring is rotatably coupled.

A sprocket wheel for a bicycle is provided with a plurality of first teeth; a plurality of second teeth alternating with the first teeth; and a plurality of recesses on one side, each recess extending from one first tooth to the adjacent first tooth via the second tooth between the two first teeth.

A sprocket wheel for a bicycle is provided with a plurality of first teeth; a plurality of second teeth alternating with the first teeth; and a plurality of recesses on one side, each recess extending from one first tooth to the adjacent first tooth via the second tooth between the two first teeth.