Originally Posted by
vane171
I was wondering if that has an automatic shifting mode whereby it would downshift or upshift for you whenever the cadence would change either way. You would set cadence range on your cyclocomputer, say 75-85 rpm and the system would shift as you started to approach either limit so your cadence would stay within the limit.
In general, riders don't stay within a narrow range of rpm (or power, or crank torque, or effort) unless the conditions stay within a narrow range. The more variable the conditions (wind, or slope, or riding with a group, or fatigue) the greater the range in rpm, power, speed, or crank torque. Cadence turns out to be a poor control variable, so it's a poor basis for automatic shifting.