He learned (painfully) to ride with training wheels in May. But he relied on the training wheels too much and they became loose and wobbly. He hated that so we took them off. But then he had nothing to lean on, which he hated even more. So we put them back on. But they still wobbled, so we took them off. We tried putting on new training wheels but by then he was just too nervous for anything to work and we just ended up taking the new ones back off. They went on and off over and over again for a couple of months before I said, "Enough!" and just gave up on the whole endeavor.
Then one morning (July 19th, to be exact) he figured out how to balance his bike. It was currently in no-training-wheels mode and he scooted it along like a balance bike, even though the pedals left him very little room to maneuver. He did that all the way to the bank and you can see it in this picture:
On the way home, he would pedal halfway around with one foot, then pedal halfway around with the other foot, always keeping one foot free to scoot along on the ground. Still, I could tell he was getting close and I was so excited!
When we got back to our apartment, he was excited to keep experimenting. He looked like he wanted to pedal with both feet so I offered to hold onto the back of the bike for him. I had tried that before and been completely unable to hold him up because he was leaning so far to one side. But on this day, he was balancing all by himself and I was hardly stabilizing him at all. After only a couple of runs down our driveway, I let go and ran beside him. We were both elated!
As soon as his friend got home, Soren showed him his new skill and they raced down the driveway. He was so proud of himself.