Electronic transmission control system for a bicycle

A method for controlling gear changing in a bicycle transmission comprising the steps of:

• calibrating the bicycle transmission by calculating a gear ratio from sensed bicycle speed and sensed cadence for each position of a derailleur in the bicycle transmission during a calibration mode;
• sorting the calculated gear ratios during the calibration mode;
• calculating a theoretical cadence from sensed bicycle speed and calculated gear ratio during an operational mode;
• determining if the calculated theoretical cadence is within predetermined limits;
• and
• providing a signal if the calculated theoretical cadence is outside the predetermined limits.

A transmission control system for a human-powered vehicle, comprising:

• a gear means;
• a crank means coupled to the gear means;
• cadence determining means for determining a cadence of the crank means;
• adjusting means including at least one actuator comprising motor means and at least one bellcrank pivotally coupled to and controlled by the at least one actuator;
• and
• computer control means responsive to the cadence determining means, for controlling the adjusting means, the computer control means comprising means for comparing the cadence with predetermined limits, means responsive to the comparison means for controlling the adjusting means, and at least one gear position sensor.

A bicycle transmission control system, comprising:

• a derailleur means for moving a chain between gears;
• means for sensing a position of the derailleur means;
• means for sensing bicycle speed;
• means for sensing a cadence;
• and
• control means, responsive to the means for sensing a position of the derailleur means, the control means comprising calculation means for calculating a gear ratio in response to sensed bicycle speed and sensed cadence for each position of the derailleur means, for controlling the position of the derailleur means.

In a bicycle having at least one set of sprockets coupled to at least one wheel and a chain which is selectably moved between individual sprockets int he set of sprockets by an adjusting means, a programmable, retrofittable control system, comprising:

• switch means for entering data relating to at least a physical configuration of the at least one set of sprockets;
• reprogrammable memory means for storing the data relating to at least the physical configuration of the at least one set of sprockets and data relating to a state of the adjusting means for any selected individual sprocket in the set of sprockets;
• accessing means for retrieving the data stored in the memory means;
• means for receiving commands from a rider, the commands indicating a desired position of the adjusting means;
• and
• control means, responsive to the means for receiving command and the data retrieved by the accessing means, for controlling the adjusting means to move the chain to any selected individual sprocket in the set of sprockets.