To Motivate a Child

Some of my goals for the summer had been to help Anders learn to ride his bike without training wheels, to be able to do the monkey bars and to learn to swing by himself. He's kind of able to do the monkey bars when he's motivated, and he can pump on the swing when he doesn't get too focused because then he becomes frustrated. He won't let me help him on the bike if he's too scared to try, which is most of the time. I try to only use encouraging words and tell him that I believe in him. That doesn't seem to work. He's got to want to do it on his own, and apparently I can't motivate him to want that (well, maybe money or the promise of new Legos or Star Wars toys could work, but we're not going down the bribery road). So if you've got any pointers, I'd love to hear them. Until then, I'm working with my 2 1/2 year old. He wants to be able to do those things.