Patent attributes
An electronic rear derailleur comprising a fixing part, a drive element, a transmission assembly, a linkage unit, and a chain adjusting portion. The fixing part has a first joint and a fixing end. The drive element drives a drive wheel. The transmission assembly has a transmission shaft and a transmission element. The linkage unit includes a base, a revolving wheel, and a gear set. The revolving wheel is engaged with the drive portion, and the gear set is disposed in the base. The base has a first and a second end, and the chain adjusting portion has a second joint pivotally connected to the second end, so that the chain adjusting portion rotates relative to the base. The gear set is connected with the first and the second joint so as to make the first and the second joint synchronizely rotate, so that the adjusting portion shifts the chain.