[mepstein]

You use your gears for optimum cadence but the optimum will vary depending on what you are doing. Climbing hills out of the saddle, around 60. Steady flat road, around 80-90, sprinting to catch the guy in front of you, 120+. If it was always 85, we would just have computerized shifting like an automatic car but that's not the way our bodies work, For example, going up a short hill, you might not shift down because you want your cadence to naturally slow down so you can stand easily and push over the hill. Going up a longer hill, you might click through the gears to keep it at 70-80 and sit the whole time. a third way to climb is to be spinning up the hill on an easier gear but then start shifting to a harder one and stand up as you get near the top. Lot's of variations and techniques because we all are different and are exposed to different situations.