Don't ask me why we never tried this until our third time around with teaching a little one how to ride a bike. Until now, we've always used training wheels, run along behind, then release when our little one is ready to take off. Which, in the case of Number 3, was taking longer than desired for a little boy who was struggling to keep up with big brothers. And then we learned this trick:
1. Take pedals off of bike. (Make sure your kiddo's feet can touch the ground.)
2. Kiddo rides bike Fred Flinstone style.
3. Kiddo learns balance and confidence in a day.
4. The next day (or two), put the pedals back on, and off he goes!
Learning to ride a bike. Boom. Done. Piece of cake!