Quote Originally Posted by DebW
Give it more time to get used to these gears. If you really need a lower gear for hills you ride frequently, then you should go for it rather than risking damage to your knees. But the compromise is wider-spaced gears which you are already having trouble with. So maybe avoid the biggest hills for awhile and ride the bike like this until you are really used to the bike and the gears. Then gradually start to ride bigger hills and see where you'd prefer to compromise. You can probably switch your 12-25 cluster for a 12-27 without too much hassle and without losing your close spacing on the smaller cogs. Your preference and your compromise point may change with your fitness level.
As of yesterday, I have just over 600 miles on the bike. Most of my riding is on level rail-trails. When I do get out on hills, it's usually pretty small ones. I don't have too much trouble with a short, steep hill, but those long, lower gradient ones really get to me. Yesterday, though, when I was heading uphill on a 2-3% gradient for 15 miles and ended up pedaling 95rpm/10mph, I was totally disgusted.

Just what happens when you switch to cogs with larger spacing? Is it harder to shift? Does it not fit as well on the bike frame?

There's been kind of a flurry of threads on this subject lately, so I'm apparently not the only person wanting to tweak her gearing. It's been a great learning experience to read all of the comments and it's really appreciated!