I changed my previous bike over from a Triple to compact double. It was a full ultegra bike, and only had to change the cranks and rear derailleur. The triple rear derailluer was a long cage and could never get it adjusted right. Bought a short cage rear derrailuer and adjusted it and it was perfect. I had to adjust the front derailleur a couple times to find the "sweet spot" for making the large jump from small to large ring, but it shifts incredible. And if you need a short cage rear derailleur, I have a extra ultegra one with less than 20 miles on it I was keeping for a spare but am switching to sram.