Electronically servo-assisted bicycle gearshift

The invention relates is used for method of electric servo auxiliary electric servo auxiliary transmission bicycle, comprising steps: Bearing (101,102) from support comprising a bicycle transmission chain at least two sprocket gears' the first sprocket wheel of transmission and transferred to the adjacent second sprocket gear signal; The multiple (101) and a sprocket wheel is bigger than the second sprocket gear is less, obtains (103) is used for second sprocket with upward speed change position, the multiple (102) and a sprocket wheel is bigger than the second sprocket wheel diameter more, obtains (104) is used for second sprocket with a speed change position; And drives the driving device (109,110) and group is arranged on the transmission shaft set parallel guide element from the first sprocket gear shifting to respectively to and the second sprocket with upward speed change position or is driven by the second sprocket with a speed change position. The invention relates is further suitable for carrying out the method for bicycle transmission, and a process and is used for carrying out method and device for electronic circuit.