Every once in a while he would go out and give it a try and come back in after about a minute. I got him a bigger bike around his birthday and gave him a few tips on starting, had cousins over to ride, and he looked like he was going to have a breakthrough, but not quite. Then we started talking about visiting his cousin over the summer and watched a video of said cousin riding his bike up and off a ramp.
After a super-rainy-cooped-up-in-the-house Memorial Day weekend, we let the kids go out and play Sunday after church. Jack came in after a little while and said, "Mom, come out and see what I can do. I'm awesome!" I go out and he RIDES HIS BIKE around the yard. I was appropriately excited for him and he was beaming.
Monday morning he was up at 6:30 and dressed, something that has not happened since he was five years old, two years ago. I asked him not to wake any one else up. He said, "I'm not. I just want to go in the back and ride my bike." I say okay, but please put on some shoes. Inside I'm saying YES!! FINALLY!! This from the boy who thought it was a punishment every time I took him out to practice riding. He finally got it, just in time to ride his bike to school every day for the last week of school.