Downhill is when you need the big ring. As I posted in another thread, I didn't think we needed anything bigger than 53-11 until racing on a mountainous course.

At Masters Nationals, we tried to attack coming down Mt Bachelor. Got a bit of seperation, but we were spinning almost 140rpm in the low 50's, and it was just too unstable to try to pedal faster.

In that admittedly rare circumstance, a 56, or even a 60 would have been handy.