Regarding standing up: I read a tip on the roadbike rider site that cleared something up for me. I don't know whether it applies to you or not. I realized that when I stand up on hills I was leaning too much to the front of the bike, which actually weights the front wheel and slows one down. There is a "sweet spot" for climbing that is a better balancebetween front and back. Maybe you are too far forward or back? Also, be sure to counterweight your weight on the handlebars so that the front keeps steady, with no more than 6" or so of rocking.