Patent ID: 7712566
Filing Date: 2010-05-11
Classification: B62K,B62M,Y10T

Abstract:
1. A bicycle transmission assembly mountable to a bottom bracket shell of a bicycle frame, the bicycle transmission assembly comprising: an input crank assembly mounted to a rotatable crank axle mounted to the bottom bracket shell; an output chainring for engaging a bicycle drive chain; a planetary gear mechanism mounted to the bottom bracket shell and providing a plurality of transmission paths, the planetary gear mechanism including a plurality of planet gears operatively connected to the input crank assembly, a sun gear, a ring gear and a locking element operatively connecting the sun gear and the ring gear; and a control system operatively connected to the planetary gear mechanism for selecting one of the plurality of transmission paths, wherein rotation of the input crank assembly drives the planet gears to overdrive the ring gear in a first transmission path of the plurality of transmission paths.