see that's the thing about fit.
The seat on my Trek hybrid always grabs my butt when I stand up. When I demo'ed a Specialized Ruby I had no trouble standing to climb.
I think deanna's just asking about getting used to it. And I think that's a matter of just doing it. Yes, you will find that some bikes will grab your butt. Crankarm length, seat height, seat position, seat tube angle and the saddle itself all go into that. But other than that...
It's really just like getting up out of a chair with something in your hands. Think about it that way. You're moving your hips forward while keeping hold of the handlebars. If the trouble you're having is not getting up, but pedaling while standing, then yeah, try a bigger gear for sure. It's hard for most people to maintain a cadence over about 70 while standing, at least until they get used to it.
Speed comes from what you put behind you. - Judi Ketteler