Patent ID: 7806006
Filing Date: 2010-10-05
Classification: B62J,B62M,G01L

Abstract:
1. A torque measurement system for a bicycle comprising: a first crank arm and a second crank arm extending between a drive axle and pedals of the bicycle, wherein each of said first and second crank arms includes at least one stain gauge; an electrical circuit on each crank arm coupled to said strain gauges and including a transmitter for transmitting strain measurement information to a main controller representative of the strain and, therefore, the torque exerted on the axle by the pedals; a main controller mounted to the bicycle and including a receiver for receiving information from said transmitters of said first and second crank arms and further including a first sensor for detecting the position of a bicycle drive sprocket as it rotates through a cycle of operation and supplying information to said main controller relative to the detected position of said sprocket, wherein said first sensor is an optical sensor and wherein teeth of the sprocket interrupt the light beam of the optical sensor to provide timing signals representative of the position of the sprocket as it rotates through a cycle of operation; and an index position sensor for supplying information as to a reference location of the crank arm with respect to a cycle of operation, wherein said index position sensor is a Hall effect sensor positioned on the frame of the bicycle and wherein one of said first and second crank arms includes a magnet for providing a signal from said Hall effect sensor when said one crank arm passes a predetermined location during a cycle of operation.