A distance determination method has: detecting a first received signal strength indicator (RSSI) of a first electronic device by a second electronic device; detecting a second RSSI of the second electronic device by the first electronic device; obtaining the first RSSI from the second electronic device by the first electronic device; and calculating a motion direction and a distance of the second electronic device relative to the first electronic device according to the first RSSI and the second RSSI by the first electronic device.

A centrally-mounted drive mechanism used for a power-assisted bicycle, and a power-assisted bicycle. The centrally-mounted drive mechanism comprises an outer casing (1), an electric motor (2), a planetary gear mechanism in a transmission connection with an output shaft of the electric motor (2), a bevel gear driving end (9), and a bevel gear driven end (10) that meshes with the bevel gear driving end (9), said bevel gear driven end (10) being connected to a crankset (13). The planetary gear mechanism comprises a planetary gear (4) and a planetary gear output bracket (5), and a bevel gear support base (8) that is sleeved on the outer part of the planetary gear output bracket (5). A clutch (6) is disposed between the planetary gear output bracket (5) and the bevel gear support base (8), and a transmission connection is formed by means of the clutch (6) between the planetary gear output bracket (5) and the bevel gear support base (8). The bevel gear driving end (9) and the bevel gear support base (8) are coaxially and fixedly connected, and a support assembly (7) is mounted on the outer part of the bevel gear support base (8), said support assembly (7) being used to support the planetary gear output bracket (5) and the bevel gear driving end (9). The axial length of the centrally mounted drive mechanism is relatively short, and thus the overall structure and volume are more compact, thus making it convenient to install a battery with a greater capacity on the power-assisted bicycle, and increasing endurance capacity.

A centrally-mounted drive mechanism used for a power-assisted bicycle, and a power-assisted bicycle. The centrally-mounted drive mechanism comprises an outer casing (1), an electric motor (2), a planetary gear mechanism in a transmission connection with an output shaft of the electric motor (2), a bevel gear driving end (9), and a bevel gear driven end (10) that meshes with the bevel gear driving end (9), said bevel gear driven end (10) being connected to a crankset (13). The planetary gear mechanism comprises a planetary gear (4) and a planetary gear output bracket (5), and a bevel gear support base (8) that is sleeved on the outer part of the planetary gear output bracket (5). A clutch (6) is disposed between the planetary gear output bracket (5) and the bevel gear support base (8), and a transmission connection is formed by means of the clutch (6) between the planetary gear output bracket (5) and the bevel gear support base (8). The bevel gear driving end (9) and the bevel gear support base (8) are coaxially and fixedly connected, and a support assembly (7) is mounted on the outer part of the bevel gear support base (8), said support assembly (7) being used to support the planetary gear output bracket (5) and the bevel gear driving end (9). The axial length of the centrally mounted drive mechanism is relatively short, and thus the overall structure and volume are more compact, thus making it convenient to install a battery with a greater capacity on the power-assisted bicycle, and increasing endurance capacity.

A straddled vehicle, including a head pipe, a main frame extending rearward from the head pipe, a fuel tank supported by the main frame, an air cleaner arranged in front of the fuel tank, a side cover formed on a lateral side of the fuel tank to partially overlap the fuel tank in a side view of the straddled vehicle, an intake port provided at an edge of the side cover and opening toward an outside of the straddled vehicle, an air cleaner chamber in which at least a part of the air cleaner is arranged, and an intake passage including a first passage between the side cover and a side surface of the fuel tank, the intake port communicating with the air cleaner chamber through the intake passage. The side cover includes a front portion located forward of the air cleaner, and the intake port is arranged rearward of the air cleaner.

An electric bicycle assembly for propelling a bicycle includes a bicycle that includes a first chain sprocket and pedals coupled to the first chain sprocket for rotating the first chain sprocket to propel the bicycle. A second chain sprocket is coupled to the first chain sprocket such that the second chain sprocket is rotated when the first chain sprocket is rotated. A generator is coupled to the bicycle and the generator is rotated to generate electrical energy when the pedals are pedaled. A motor is coupled to the bicycle and the motor is in mechanical communication with the rear wheel. The motor rotates the rear wheel when the motor is turned on for propelling the bicycle.

A battery holder 54 for fitting a battery pack 52 to a frame 4 of a cycle 2 comprises a spine portion 100 for fixing to the frame 4; a connector portion 110 to form an electrical connection between the battery pack and wiring; and a battery moving portion 115 for moving the battery pack 52 towards the connector portion to engage the battery pack with the connector portion. A lever mechanism 120 actuates sliding of the battery moving portion 115 in a linear direction between an open state providing clearance for insertion/removal of the battery pack and an engaged state for engagement of the battery pack 54 and connector portion 110. The lever mechanism 120 has a retained state which provides resistance to removal of the battery pack from the battery holder. This provides a simple to install and fasten holder which securely holds the battery pack.

A battery holder 54 for fitting a battery pack 52 to a frame 4 of a cycle 2 comprises a spine portion 100 for fixing to the frame 4; a connector portion 110 to form an electrical connection between the battery pack and wiring; and a battery moving portion 115 for moving the battery pack 52 towards the connector portion to engage the battery pack with the connector portion. A lever mechanism 120 actuates sliding of the battery moving portion 115 in a linear direction between an open state providing clearance for insertion/removal of the battery pack and an engaged state for engagement of the battery pack 54 and connector portion 110. The lever mechanism 120 has a retained state which provides resistance to removal of the battery pack from the battery holder. This provides a simple to install and fasten holder which securely holds the battery pack.

An electric drive motorcycle (100), comprises: a front portion comprising one or more front wheels (103) and a handlebar (104); a rear portion comprising a saddle (101), a shell body (107) arranged below said saddle (101), and a rear wheel (105) arranged below said shell body (105); an intermediate portion (108) extending as a connection between said front portion and said rear portion; an electric drive unit (8) connected to said rear wheel (105); a power supply unit feeding said electric drive unit (8); and a helmet carrying compartment (11) placed in the shell body (107) below the saddle (101), wherein said power supply unit is arranged in a position below said helmet carrying compartment (11), so that said saddle (101), said helmet carrying compartment (11) and said power supply unit are substantially stacked on each other, being said helmet carrying compartment (11) and said power supply unit arranged inside the shell body (107), wherein said supply unit comprises a battery unit (15) or a battery unit (15) and an electric motor/generator, wherein a control unit apt to control said drive unit (8) and said battery unit (15) is provided, said control unit comprising a case (20) arranged below the battery unit (15), wherein a rear fork (1) jointed to the shell body (107) is provided, said rear fork comprising at least a fork arm (3, 4) extending between said shell body (107) and said drive unit (8), and wherein said rear fork (1) is placed beside and/or surrounds said case (20).

An electric drive motorcycle (100), comprises: a front portion comprising one or more front wheels (103) and a handlebar (104); a rear portion comprising a saddle (101), a shell body (107) arranged below said saddle (101), and a rear wheel (105) arranged below said shell body (105); an intermediate portion (108) extending as a connection between said front portion and said rear portion; an electric drive unit (8) connected to said rear wheel (105); a power supply unit feeding said electric drive unit (8); and a helmet carrying compartment (11) placed in the shell body (107) below the saddle (101), wherein said power supply unit is arranged in a position below said helmet carrying compartment (11), so that said saddle (101), said helmet carrying compartment (11) and said power supply unit are substantially stacked on each other, being said helmet carrying compartment (11) and said power supply unit arranged inside the shell body (107), wherein said supply unit comprises a battery unit (15) or a battery unit (15) and an electric motor/generator, wherein a control unit apt to control said drive unit (8) and said battery unit (15) is provided, said control unit comprising a case (20) arranged below the battery unit (15), wherein a rear fork (1) jointed to the shell body (107) is provided, said rear fork comprising at least a fork arm (3, 4) extending between said shell body (107) and said drive unit (8), and wherein said rear fork (1) is placed beside and/or surrounds said case (20).

An electrically powered bicycle equipment has an attachment/detachment seat for an electric power supply unit, and a latch assembly for holding the electric power supply unit in the seated state includes a slider having a head and a back. Either the electric power supply unit or the equipment has a sliding seat for the slider, the other one has a retaining seat for the head. The sliding seat accommodates the back of the slider, which has a peripheral groove and a ring gasket housed in the peripheral groove. The groove has two aligned sections and a deeper intermediate section between them. When the slider is in the fully advanced position, a gasket portion bridges the intermediate section between the two aligned sections, and when the slider moves back, the gasket portion can curve towards the bottom of the intermediate section of the peripheral groove.