I am building a new bike and am switching from an FSA Compact 50/34 12/25 to a Cannondale SI 53/39. I want to keep my climbing gears but also do not want to spin out on downhills. I feel as if I need an 11 gear on the low end, but don't know if the 23 will give me enough for climbing? I looked for an 11-25 and can only find a junk Token cassette. People have told me about switching out the drive unit in my wheels to a shimano compatible but I use a Campagnolo wheel and cannot do that. If anyone can tell me what my best fit would be to mirror the compact crank, I would geatly appreciate it.