FWIW, DD (4 as of next week) just got on a bike with training wheels for the first time a few weeks ago. DS7 was freewheeling without training wheels last summer at 6. He was close the year before then winter came upon us. He was held back a bit by the long, hard winters we endure! This year he got a little bit bigger bike with gears and hand brakes and he can go for miles and miles - quite fun! I still like our really big trike for our 4 year old.
Anyway - keep those training wheels on!
And DS7 was a big fan of the naked dance. A lot of times he still leaves his pants by the door when he comes in. At least he doesn't do it at other people's houses anymore!
