We bought our son a balance bike from REI when he was 18 months old. Around 2 years old he started trying to ride it but was frustrated after falling. He would get on it a few times but never really wanted to ride it. Around 3 years old he started having an interest in it and loved riding it. We let him ride it inside the house also and do laps which helped. A few months before he turned 4 we bought him a 14” WOOM bicycle. I ended up putting training wheels on it just so he could learn how to pedal. After a month we took the training wheels off and he has been crushing it. I just purchased a 16” Trek for him, but it’s a little big and I think I was starting to rush him. But the 14” bike is starting to look small and he is out pedaling the bike.