Quote Originally Posted by maillotpois View Post
Nice! Have lots of cake and eating it, too!

That's exactly how I spec'd my gears to Chris: "I want my cake and eat it."

It seems that you're limited to a 22 tooth range on the Shimano front derailleurs, so for example 30-52 would meet that. Also it seems that 52 is as high as you can go for the large ring, just browsing some Shimano info. Most of the mountain rear ders. take a 34t sprocket, so that's good. Make sure you check the specs to be sure the derailleurs have enough capacity for what you want. Some of the front ders only take a max of 48 teeth on the large chainring, for example. Then watch the total capacity rating, which is the front capacity + rear capacity. So if you want a 30-52 in front and 11-34 in back, that's 22 + 23 = 45 as the total capacity.

This blurb explains it pretty well, http://sheldonbrown.com/gloss_ca-g.html#capacity

He says you can exceed the mfg's specs a bit, but that will get you into finicky shifting, which should be avoided since there are so many good options available in Shimano.