Originally Posted by
AlexCyclistRoch
Don't over-think it too much. You can pretty much use EVERY gear when the front derailleur is in the middle ring, and you really only need to avoid the large-large and the small-small combo on a 7-speed.
"Don't over-think it too much." That's what I think too.
Think of your left (front) gears as 3 ranges: one for uphill, one for the flats, and one for downhill. Within those gear ranges, use your right (rear) shifter to keep your feet spinning at a comfortable rate. That's pretty much all that you need to know. If you do it that way you'll seldom or never get yourself into the cross chaining combinations.