Need Education on Compact Double verses Triple

[Kalidurga]

Whether you can climb hills or not with a compact depends on what your cog range is (which I've been learning the hard way this year ). A 34 tooth chain ring is perfectly sufficient for climbing, I think, if you have a big enough cog in the rear.

Two things I love about my compact chainring: Easier cleaning, and no chain suck

[rij73]

My current bike has a 52-42-30 triple and my new bike is getting a 50-34 double. What I did was make sure to get a 12-27 cassette in the back. The 34 chainring with the 27 in back is only a tiny bit harder to pedal than the 30-26 combo I have currently. The bike will be 6 pounds lighter, so that should make up for it!

Check out this nifty online tool:
http://www.sheldonbrown.com/gears/

If you know the size of your old cassette and new cassette, you can use the tool to see how your new gearing compares to the old!

[HillSlugger]

Chainring teeth divided by cog teeth gives you a power factor. If your largest cogs are the same you'd be getting something like 18% less low gear power from the compact double.

My 35 lb hybrid had a 28/34=0.82 low gear ratio. On my 23 lb triple road bike my lowest is 30/27=1.11 I could climb almost anything on that hybrid, even with the weight penalty.