Originally Posted by Kingby

First step is drive train telling head unit the gearing metrics for the record and later analysis. I am thinking the next step will be the user entering power/cadence/heart rate/speed parameters into the head unit and algoriths of the head unit (garmin or whatever) being able to control the gearing keeping the rider within power/cadence/speed/heart rate parameters. May not appeal to all, but I can see merits with regards to training and coaches being able to provide very specific training plans etc... Essentially auto-shift.