I am in need of info on how to determine what is the best Chain Rings\Cassette combo to have on my road bike. On my hybrid, I was riding a 48-38-28 triple with a 11-32 cassette, I changed the cassette to more road based 12-23 and it was working out fairly well for me. On my new bike, I have a 53-39 double with a 13-25 cassette. I find myself almost always in the large ring in about the 5th or 6th cog through out the ride. Doesn't leave a lot of options. On my Hybrid, I would ride about 65 in the middle and 35 in the large and had almost the entire cassette to play with if needed.
Since I basically know squat about gear ratio's other the very extreme basics, I want to learn more about it. So, 1. A good resource, looked on Sheldon's site, not much on it, and 2. is a 12-23 a better option with the 53-39 on the front than the 13-25 since I am in the flat lands of the Southeast and tallest thing I will ride up is a bridge about 100 to 150 ft high. My house is 4 ft above sea level if that tells you how flat it is.
Any help is appreciated.