Hi,

I currently ride a Specialized Secteur 2009 model. It had a triple chainring and a 11-28 cassette. I changed the cassette to 11-32 last year so I could ride my century with about 7000ft of total elevation (max. grade was about 16%). The Secteur is an aluminum frame and I've been thinking about upgrading to carbon. Which one would you recommend?

1. My goal is to ride at least 2 centuries every year (with a lot of practice rides, of course)
2. I mainly ride hills (sometimes even 21% grade)
3. I am open to any brand bike
4. Do I need a triple chainring? I am little weak in stamina but working towards building it
5. My budget is not more than $2000 (I am assuming I can sell/trade-in my current bike)
6. I like the 11-32 cassette. My feeling is that it makes things a bit easier?
7. I am noob when it comes to bike science (You probably understood by now)
8. Do I need 105? How is Tiagra compared to 105? I have no idea.

Thanks.