On one of my bikes, I have a 30 with my standard compact Campy record rear derailleur, and that's great for all but the longest and steepest hills. My new bike has ultegra, and I built it up with a 105 long cage rear derailleur and that goes to 34 at present. I could put 36 on if I wanted to, but I feel like a 1 to 1 is enough.