I live in central California near the coast and am surrounded by hills. I mean, I am immediately faced with some sort of hill climbing as soon as I leave my house. Some are rollers, others are steep. Nothing really long and steep. I ride 42x18. Too low for many, but it saves my knees. Steep decents can be difficult, but it is all about trade-offs here. I use a Trek 520 for commuting and my fixed gear for just fun, around town kind of stuff.