A electric motor system for supplying assistive propelling power to a bicycle, comprising: one or more drivetrains, each comprising a motor-drive shaft having a pinion with fixed drive system driving a crown and bearing assembly connected to a spindle; and a controller for executing a motor control sequence comprising: an initial state activated by a rider's start command where the motor speed is being detected for an initial period, and if the motor speed is higher than a first speed threshold continuously for a first period, then the motor is turned on to output a rider-selected torque level; a continuous motor speed detection state where the motor speed is being continuously detected, and if the motor speed falls below a second speed threshold continuously for a second period, then the motor is turned off; and the motor is turned off if a stop command from the rider is received.

A crank apparatus equipped with a labor-saving mechanism and a bicycle crank assembly are disclosed. The crank apparatus includes a crank mechanism, a transmission mechanism, a supporting module and a rotating arm module. The crank mechanism includes a crank, an axle-end gear and a pedal-end gear. The transmission mechanism includes a rotating axle having a circular groove. The supporting module is adapted to sheathe the rotating axle and includes an outer ring and rollers received inside the circular grooves and clamped between the rotating axle and the outer ring. The rotating arm module includes a first rotating arm and a second rotating arm. One end of the second rotating arm is connected to the first rotating arm, and another end of the second rotating arm is connected to the pedal-end gear. Accordingly, the transmission stability and useful lifetime of the crank apparatus and bicycle crank assembly are increased.

A bicycle bearing system comprising: an integrated cup, the integrated cup having an outer diameter; a plurality of rolling elements configured to abut and rotate against a first race groove located on an inner surface of the integrated cup; a second race groove configured to abut and rotate about the plurality of rolling elements, the second race groove located on an inner surface of the inner race, the inner race having an inner diameter; where the rolling elements do not have a separate outer race, but rather the inner surface of the integrated cup acts as the outer race to the rolling elements; and where the rolling elements, integrated cup and inner race are axially locked when assembled as a single cartridge unit due to the geometry of the rolling elements, first race groove and second race groove.

A bicycle having a widened rear wheel preferably includes an existing bicycle, a double tire rear wheel, a widened crank tube, a widened crank and widened rear fork. The existing bicycle includes a bicycle frame, a front wheel, handlebars, and a seat. The bicycle frame includes a frame unit and a crank set. The frame unit includes a base frame portion, a front fork and a rear fork. The base frame portion includes a top tube, a seat tube, a down tube and a crank tube. The crank tube is replaced with the widened crank tube. The rear fork is replaced with a widened rear fork. A crank of the crank set is replaced with the widened crank. The widened rear wheel preferably includes three bicycle tire rims, a plurality of spokes, two tires and a lengthened rear wheel hub.

A bicycle crank assembly includes a sprocket having a rotational center axis, a crank, a crank axle and a slide mechanism. The crank axle is attached to the crank and includes an internal space. The slide mechanism is configured to displace the sprocket relatively to the crank in an axial direction parallel to the rotational center axis. At least part of the slide mechanism is disposed in the internal space of the crank axle.

A shaft element of a bicycle bottom bracket assembly comprising a first end portion having a first coupling portion for coupling with another shaft element and an opposite second end portion having a second coupling portion for coupling with a crank arm. The first coupling portion comprises at least one reference element that defines a single mutual coupling position of the shaft element with the other shaft element. The second coupling portion comprises at least one coupling element having a predetermined angular position with respect to the at least one reference element.

A drive train for muscle-driven single-track or multi-track vehicles with a crank-driven bottom bracket gearbox which is connected on the output side to a chain or belt drive from which a chain or belt leads directly or shiftably to a pinion to a rear wheel hub, belt leads directly or switchably in each case to a pinion to a rear wheel hub, wherein in addition to the bottom bracket gearbox, which is designed as a primary gearbox with n speeds or with variable transmission ratio, a rear-mounted gearbox is also arranged in the drive train as a switchable rear wheel hub gearbox with m=two or m=three speeds, wherein n and m are natural numbers. In addition to the bottom bracket gearbox, which is designed as a primary gearbox with n speeds, the drive train also includes a rear-mounted gearbox as a shiftable rear wheel hub gearbox with m=two or m=three speeds.

A bottom bracket having a shaft having a longitudinal axis (X), first and second adapters radially outside of the shaft and associated with respective ends of a bottom bracket housing. Rolling bearings are radially interposed between the shaft and the first adapters with axial locking members axially outside the rolling bearings and in axial abutment on the first and second slewing bearings. A protective screen, positioned between a selected adapter and a radially outer surface of the associated axial locking members in the axial direction and at least partially outside of the first adapter, is fixedly connected to the selected adapter and comprising a sealing member arranged in sliding contact on the radially outer surface of the associated axial locking members.

A bottom bracket for a bicycle may include a left bearing cup and a right bearing cup, the two bearing cups configured to be threaded together within a bottom bracket shell. Threading the bearing cups together may result in an axial force being applied to a resilient ring disposed on one of the bearing cups. This axial force may cause an outer diameter of the resilient ring to expand against an inner surface of the bottom bracket shell, thereby effectively locking the bottom bracket into the shell.

A bicycle crank assembly includes a fixing member for fixing a sprocket to a crank arm. The fixing member includes a radially-extending projection, to prevent the sprocket from moving relative to the crank axle in an axial direction, and an axially-extending base portion, which is secured to the crank arm. A contact part is provided on an inner periphery of the base portion and contacts the crank axle or is provided on the crank axle and contacts the base portion. The contact part permits force to be transmitted between the crank axle and the fixing member to limit flexing of the crank axle assembly.