Yep, you'll be fine. I have a similar time up Lookout and just did the Sunrise Century 75 mile course this weekend with a compact 50/34 11-28 with no trouble. Total climbing was only about 400' less than the Copper Triangle. One caveat though, I have also done High Grade with a 53/39 11-25 without too much trouble (definitely not at a cadence of 80 though! ;^)