While I haven't yet met a grade I couldn't climb, I have been thinking about switching from my 53/39 12-25 set up to a compact. If I can spin up a little more easily and efficiently it should make me faster too, right? I don't know how much difference it really makes though, so I'm worried that I may not even notice a difference? Or should I change the cassette? Tell me your experiences And what are your thoughts and advice? By the way I'm 46 and I also think the compact set-up may help preserve the health of my knees.