Transmission system for cycle, has upper tube with steering rack fixed on axis and case with differential clearance positioned such that pedal crank permits vertical reciprocal to and fro alternative movement

摘要

The system has a rear yoke (11) articulated around an axis (Fx) on a front frame. A rear frame has an upper tube fixed at the level of a frame head (20). A reinforcement fork (12) extends between a fixation centre of a rear wheel and the tube. Pedal crank (1D, 1G) is articulated at ends of shafts (2). A chain (6) transmits power between a crown plate (5) and pinion cartridges (8). The tube has a steering rack (3) fixed on an axis (Cx) and a case (15) with differential clearance which is positioned such that the pedal crank permits vertical reciprocal to and fro alternative movement.