mine have all loved riding. when my wife leaves me with the kids, thats what we do. the older 2 would go to sleep within minutes when they were babies. all of that fresh air in the face just put'em out. the baby, she can't get enough. when i'm working daylight, her and i will go every evening. some nights we put on 20 or 30 miles, other nights we just ride down to the store and get an ice cream cone.
i bought my son a PW50 for his 3rd birthday, and that may have been a little too early since he couldn't ride a bicycle yet. the following year i bought a new Kasea 90. he rode the wheels off of it. he even raced a few times and made podium. i passed that on to my older daughter and bought him an RM60. he hated it. so i sold it and bought a honda 250ex. he rode the heck out of it. he is ready to move up again and my older daughter is already riding the 250ex. i'd like to start the bay on the 90 this summer, but my wife thinks she should wait a year. she is only four, so we'll see.