Doodle recently learned to ride a 2 wheeler. He's the 3rd child Marathon has taught to ride, and his method has changed and improved since teaching Carman & Sudoku years ago.
Marathon used training wheels to help teach the older 2 kids, and they developed the bad habit of not leaning into turns. Instead they would actually lean in the opposite direction in an effort to keep the training wheels grounded.
So this time Marathon was determined to not use training wheels at all. We had heard of the method of using a small framed bike, lowering the seat, and removing pedals and letting a little tyke learn to balance and coast that way first. We did this for Doodle, but he just didn't get into it enough to learn to balance.
We have a large tricycle that Doodle rode a lot. It has a larger crank than his little bike. It was on the large wheeled trike that he got pedaling experience and built up leg strength.
Also, Marathon built a small wooden seat and attached it to the bars on his own bike. Doodle would sit on the seat in between Marathon's arms and they would ride together, with 2 pairs of hands on the handlebars. The idea was to help Doodle get used to steering and leaning into the turns.
When his pedaling skills were well developed, Marathon got a stick from a broken garden tool and attached it to the back of Doodle's bike. I think he just wedged it between some bars on the bike's frame, and Marathon would run along behind Doodle to help him balance. When Doodle would start to fall, Marathon would let him down easily, until he put his foot down.
Finally Doodle was ready to go it alone. Like we did with Sudoku, we went to a nearby church with a huge gently sloping lawn. At the top of the hill Marathon got him going, told him to pedal hard and gave him a push. Marathon let go of the old tool almost immediately, unbeknownst to Doodle. As Doodle neared the bottom of the slope, Marathon, who had been verbally cheering him on all along, slowly ran beside, then in front of him. Doodle did a double take and dropped his jaw, then started to giggle. I wish you could have seen the look on his face! He was so surprised and pleased with himself!
He did the hill another time or two, having help getting started. Now Carman is practicing with him in the backyard, helping him learn to start by himself.