An electronic device comprises a wireless transmitter and an operation device. The operation device comprises a base, a brake lever, operation portions and an electronic controller. The base is to be removably attached to a handlebar. The operation portions includes first, second and third operation portions. The first operation portion is arranged on the base. The second and third operation portions are arranged adjacent to the brake lever and are disposed between the brake lever and the handlebar. At least one of the operation portions includes a lever. At least one of the operation portions includes a button. The electronic controller is configured to transmit an operation signal to the wireless transmitter upon operation of any of the operation portions to control at least one bicycle component that is any one of a shifting device, a brake device, an adjustable seatpost, a suspension and a drive unit.

A bicycle chain comprises a first outer link plate and a second outer link plate. A first outer-link longitudinal axis extends through a first outer-link center axis and a second outer-link center axis to divide a first outer surface into a first side and a second side when viewed in an axial direction. A second outer-link longitudinal axis extends through a third outer-link center axis and a fourth outer-link center axis to divide a second outer surface into a third side and a fourth side when viewed in the axial direction. The fourth side includes a first circumferential area and a first chamfer free area. The first circumferential area has a first angle equal to or larger than 20 degrees. The first chamfer free area is adjacent to the first circumferential area. At least one second chamfer is provided outside the first chamfer free area.

A bicycle chain comprises a first outer link plate and a second outer link plate. A first outer-link longitudinal axis extends through a first outer-link center axis and a second outer-link center axis to divide a first outer surface into a first side and a second side when viewed in an axial direction. A second outer-link longitudinal axis extends through a third outer-link center axis and a fourth outer-link center axis to divide a second outer surface into a third side and a fourth side when viewed in the axial direction. The fourth side includes a first circumferential area and a first chamfer free area. The first circumferential area has a first angle equal to or larger than 20 degrees. The first chamfer free area is adjacent to the first circumferential area. At least one second chamfer is provided outside the first chamfer free area.

A bicycle rear sprocket comprises a sprocket body and a plurality of sprocket teeth. The plurality of sprocket teeth includes at least one driving tooth configured to engage with a roller of a bicycle chain. The at least one driving tooth comprises a driving surface, a first tangential line, a first angle, a second tangential line, and a second angle. The driving surface includes a first driving surface and a second driving surface. The first driving surface has a first contact point. The second driving surface has a second contact point. The first angle is defined between the first tangential line and a reference line. The second angle is defined between the second tangential line and the reference line. The first angle is smaller than the second angle.

A bicycle rear sprocket comprises a sprocket body and a plurality of sprocket teeth. The plurality of sprocket teeth includes at least one driving tooth configured to engage with a roller of a bicycle chain. The at least one driving tooth comprises a driving surface, a first tangential line, a first angle, a second tangential line, and a second angle. The driving surface includes a first driving surface and a second driving surface. The first driving surface has a first contact point. The second driving surface has a second contact point. The first angle is defined between the first tangential line and a reference line. The second angle is defined between the second tangential line and the reference line. The first angle is smaller than the second angle.

A bicycle rear sprocket assembly 28 comprises a sprocket carrier 31, at least one metallic support 33, and at least one rear sprocket 28a-28h. The sprocket carrier 31 is made of a non-metallic material. The at least one metallic support 33 is attached to at least one of a first circumferentially facing surface 41 and a second circumferentially facing surface 43 of at least one mounting arm 39 of the sprocket carrier 31. The at least one rear sprocket 28a-28h is made of a metallic material. A sprocket body 51 of the at least one rear sprocket 28a-28h is attached to the at least one metallic support 33.

A bicycle sprocket comprises a sprocket body and chain-driving teeth. The chain-driving teeth comprises at least one first tooth and at least one second tooth. The at least one first tooth has a first circumferential tooth-length defined in a circumferential direction at a radial location defined in vicinity of a reference line. The at least one second tooth has a second circumferential tooth-length defined in the circumferential direction at the radial location. The first circumferential tooth-length is larger than the second circumferential tooth-length. A dimensional difference between the first circumferential tooth-length and the second circumferential tooth-length is equal to or smaller than 1 mm.

A bicycle sprocket comprises a sprocket body and chain-driving teeth. The chain-driving teeth comprises at least one first tooth and at least one second tooth. The at least one first tooth has a first circumferential tooth-length defined in a circumferential direction at a radial location defined in vicinity of a reference line. The at least one second tooth has a second circumferential tooth-length defined in the circumferential direction at the radial location. The first circumferential tooth-length is larger than the second circumferential tooth-length. A dimensional difference between the first circumferential tooth-length and the second circumferential tooth-length is equal to or smaller than 1 mm.

A bicycle sprocket comprises a plurality of sprocket teeth including at least one first tooth and at least one second tooth. The at least one first tooth has a first non-driving surface including a first non-driving surface portion and a second non-driving surface portion so that a first ridge is formed between the first non-driving surface portion and the second non-driving surface portion. The at least one second tooth is configured to initially engage with the bicycle chain in a shifting operation. The at least one second tooth is disposed adjacent to the at least one first tooth. The at least one second tooth has a second non-driving surface including a third non-driving surface portion and a fourth non-driving surface portion so that a second ridge is formed between the third non-driving surface portion and the fourth non-driving surface portion.

A bicycle sprocket comprises a plurality of sprocket teeth including at least one first tooth and at least one second tooth. The at least one first tooth has a first non-driving surface including a first non-driving surface portion and a second non-driving surface portion so that a first ridge is formed between the first non-driving surface portion and the second non-driving surface portion. The at least one second tooth is configured to initially engage with the bicycle chain in a shifting operation. The at least one second tooth is disposed adjacent to the at least one first tooth. The at least one second tooth has a second non-driving surface including a third non-driving surface portion and a fourth non-driving surface portion so that a second ridge is formed between the third non-driving surface portion and the fourth non-driving surface portion.