Clamping groove type rear brake for electric bicycle

The utility model discloses a clamping groove type rear brake for an electric bicycle, which comprises a shell and a brake shoe, the shell is used for being fixed on a bottom fork of the electric bicycle, a clamping groove is arranged on the shell, the clamping groove corresponds to a bulge on the bottom fork of the electric bicycle, a cam shaft is arranged on the shell, and the brake shoe is arranged on the cam shaft. A brake rocker arm and a driving wheel are arranged at the two ends of the cam shaft respectively, an adjusting gear is arranged on the inner side of the shell and meshed with the driving wheel, and the brake rocker arm is used for driving the driving wheel and the adjusting gear to rotate. The adjusting gear is connected with a push block; the brake shoe comprises a positioning shaft and two brake blocks, one ends of the brake blocks are movably installed on the positioning shaft, the other ends of the brake blocks abut against a push block, and the push block is used for rotating and pushing