Quote Originally Posted by Biciclista View Post
a guy who used to race told me that under a load, it's easier to go from your bigger chain rings down than it is to shift the gears in the back on the cassette.
So I'd suggest you stay in your middle chain ring until you need to shift then drop into the lowest chainring... hopefully you'll still have a couple more gears in the back when you do this in case it gets even steeper.
I stay in my middle chain ring up front so as to keep up my cadence. I start to gear down in the back when my cadence falls below 70. For cyclists with faster cadence than I have, they gear down when their cadence falls below 80. If the grade gets real steep over 11%, or if it is a long climb of more than a mile and I need to conserve energy, I may ease up on my chain a bit, then shift into the granny in the front. If I have prior knowledge that I am facing a hill with a grade that is excessively steep, like over 13%, I will shift down to my granny in the front and the lowest in the back at the bottom of the climb so that I won't have to worry about dropping my chain halfway up the climb. If I didn't have prior knowledge, and find myself on a hill where halfway up it turns to a 16-17% grade, well the grade is too steep to get slack to shift into the granny, so I stay in my middle chain ring and start praying. I got up some real steep hills in my middle chain ring this year, which suprised me considerably, and even more satisfying, I passed male cyclists who dropped their chains.