My Kids learned How to Drive a Bike without Guide

It was July 8, 2009 morning my wife shocked when she saw my kids drive a bike without a guide. For me it was also a shocking point because its a long time that he did not use his bike due to some problem with the tire til now I did not buy for a replacement the defective parts. That bike was borrowed in our nearest house. I do hope that this week I can buy tire to replace my kids bike tire.