Originally Posted by UmneyDurak
I think my next bike will have compact crank. Currently I have 53/39 27/12, and it is working out just fine, but on the hills I'm spinning at ~70 rpm. I think I would preffer to have higher cadence.
There are hills that are so steep that you simply need to stand. If you're not used to standing, you can train yourself a bit at a time. When you alternate spinning and standing, it's a lot less tiring and you go faster.
If your knees are bad, you will have to train yourself very gradually. Also, be sure to adjust your cleats carefully and get pedals that work for you. A couple degrees can literally be the difference between agony and feeling great.
I have not been able to run for over 20 years and don't expect I ever will be able to, but I've never run out of gears with 39/25 (though trips in the mountains sometimes have me standing on that combo)
If you never want to stand, it makes more sense to go for the third ring and pop on an 11/32 in the rear than to go with a compact. Anything with 2 rings that would never require standing probably wouldn't leave you with tall enough gears for when you go really fast.