I'm 57 and just got back into cycling after I retired! My goal is to start riding centuries, which I haven't done since I was 42. I currently ride 120-150 per week and can do pretty good on flats and small climbs, BUT when I get to a big hill, I usually gear down and by the time I decide to stand on the pedals, I am in too low of gear to pedal while standing. HOW and WHEN (or do I) shift up to get a gear that will make standing effective? Thanx for this forum...I have learned a lot!