Interesting observations ovoleg and timely in that I'm considering a chain-ring change at the moment.

I'm currently running 53/39 with 12-25 on the CAAD10 (12-27 on the Defy) and am seriously considering 52/36 on the CAAD10, to give me that little bit more 'headroom' in the hills. Do you reckon 52/36 on the 12-25 would give me a bit more climbing capacity, yet not impact the top-end too much? Or, would a cassette change be more beneficial?

cheers