A bicycle frame is discussed having a battery fully contained within a down tube of the bicycle frame. The battery may be inserted into or removed from the down tube via a through opening through a bottom bracket housing of the bicycle frame. Weakness in the bottom bracket housing due to the through opening may be compensated for, fully or partially, by utilizing a bottom bracket bearing assembly that has a structural component, or structural component assembly, that extends completely through the bottom bracket housing and removably couples to the bottom bracket housing.

A bicycle frame is discussed having a battery fully contained within a down tube of the bicycle frame. The battery may be inserted into or removed from the down tube via a through opening through a bottom bracket housing of the bicycle frame. Weakness in the bottom bracket housing due to the through opening may be compensated for, fully or partially, by utilizing a bottom bracket bearing assembly that has a structural component, or structural component assembly, that extends completely through the bottom bracket housing and removably couples to the bottom bracket housing.

A bicycle is equipped with a dual chain drive system having two cranksets symmetrically mounted on the rear section of an adapted and compact frame. The cranksets are located in close proximity to the rear wheel hub axle to enhance the energy efficiency, responsiveness and manoeuvrability of the bicycle.

A bicycle is equipped with a dual chain drive system having two cranksets symmetrically mounted on the rear section of an adapted and compact frame. The cranksets are located in close proximity to the rear wheel hub axle to enhance the energy efficiency, responsiveness and manoeuvrability of the bicycle.

A bicycle frame assembly including a seat tube having first and second end portions (wherein the seat tube second end portion includes a bend and terminates in a first open end facing a first direction), a down tube having first and second end portions (wherein the down tube first end portion is mounted to the seat tube first end portion, and the down tube second end portion includes a bend and terminates in a second open end facing a second direction opposite to the first direction), and a top tube having first and second end portions (wherein the top tube first end portion is mounted to the seat tube second end portion and terminates in a third open end facing the first direction, and the top tube second end portion is mounted to the down tube second end portion and terminates in a fourth open end facing the second direction).

A bicycle frame is discussed having a battery fully contained within a down tube of the bicycle frame. The battery may be inserted into or removed from the down tube via a through opening through a bottom bracket housing of the bicycle frame. Weakness in the bottom bracket housing due to the through opening may be compensated for, fully or partially, by utilizing a bottom bracket bearing assembly that has a structural component, or structural component assembly, that extends completely through the bottom bracket housing and removably couples to the bottom bracket housing.

A bicycle frame is discussed having a battery fully contained within a down tube of the bicycle frame. The battery may be inserted into or removed from the down tube via a through opening through a bottom bracket housing of the bicycle frame. Weakness in the bottom bracket housing due to the through opening may be compensated for, fully or partially, by utilizing a bottom bracket bearing assembly that has a structural component, or structural component assembly, that extends completely through the bottom bracket housing and removably couples to the bottom bracket housing.

A bike frame includes including a seat tube (10) for receiving a seatpost (2), a front portion comprising a top tube (13) connecting the seat tube (10) to a head tube (16), the seat tube (10), the top tube (13). The head tube (16) extends in a plane of symmetry of the bike frame (1). A rear portion has two chain stays (11a, 11b) and two seat stays (12a, 12b) arranged symmetrically relative to the plane of symmetry of the bike frame (1). The two seat stays (12a, 12b) are independent of each other and the two seat stays (12a, 12b) have a preform that is curved along at least one arc in a plane passing through the two seat stays, so as to enable the two seat stays to move away from or closer to each other under the action of a vertical load.

A bike frame includes including a seat tube (10) for receiving a seatpost (2), a front portion comprising a top tube (13) connecting the seat tube (10) to a head tube (16), the seat tube (10), the top tube (13). The head tube (16) extends in a plane of symmetry of the bike frame (1). A rear portion has two chain stays (11a, 11b) and two seat stays (12a, 12b) arranged symmetrically relative to the plane of symmetry of the bike frame (1). The two seat stays (12a, 12b) are independent of each other and the two seat stays (12a, 12b) have a preform that is curved along at least one arc in a plane passing through the two seat stays, so as to enable the two seat stays to move away from or closer to each other under the action of a vertical load.

A bicycle frame is discussed having a battery fully contained within a down tube of the bicycle frame. The battery may be inserted into or removed from the down tube via a through opening through a bottom bracket housing of the bicycle frame. Weakness in the bottom bracket housing due to the through opening may be compensated for, fully or partially, by utilizing a bottom bracket bearing assembly that has a structural component, or structural component assembly, that extends completely through the bottom bracket housing and removably couples to the bottom bracket housing.